CN109041348B

CN109041348B - Adaptive circuit module, LED driving circuit with silicon controlled rectifier dimmer and method

Info

Publication number: CN109041348B
Application number: CN201811007069.1A
Authority: CN
Inventors: 王曙光; 杨林伟; 陈晓亮
Original assignee: Xiamen Biyi Micro Electronic Technique Co ltd
Current assignee: Xiamen Biyi Micro Electronic Technique Co ltd
Priority date: 2018-08-31
Filing date: 2018-08-31
Publication date: 2024-04-19
Anticipated expiration: 2038-08-31
Also published as: CN109041348A

Abstract

The invention discloses a self-adaptive circuit module, an LED driving circuit with a silicon controlled rectifier and a method thereof, wherein the LED driving circuit comprises the silicon controlled rectifier, a rectifying circuit, a bleeder circuit, a constant current control circuit and a self-adaptive circuit module; the self-adaptive circuit module is respectively connected with the rectifying circuit, the bleeder circuit and the constant current control circuit, and the rectifying circuit is connected with the silicon controlled rectifier dimmer; the bleeder circuit is connected with the constant current control circuit, the constant current control circuit is connected with the LED lamp, and the self-adaptive circuit module is used for adaptively controlling bleeder current in the bleeder circuit at least according to the starting information of the silicon controlled rectifier dimmer. The invention can be compatible with all the silicon controlled dimmers, and can control the starting of the silicon controlled dimmers according to the pulse currents with different amplitudes or different pulse widths or different frequencies generated by different silicon controlled dimmers, thereby improving the efficiency of different systems to the maximum extent and being compatible with all the silicon controlled dimmers.

Description

Adaptive circuit module, LED driving circuit with silicon controlled rectifier dimmer and method

Technical Field

The invention belongs to the technical field of power electronics, and particularly relates to a self-adaptive circuit module, an LED driving circuit and an LED driving method.

Background

Silicon controlled dimming is a currently commonly used dimming method. The silicon controlled rectifier dimmer adopts a phase control method to realize dimming, namely, the silicon controlled rectifier dimmer is controlled to be conducted every half period of the sine wave, and the same conduction phase angle is obtained. The magnitude of the conduction phase angle can be changed by adjusting the chopping phase of the silicon controlled rectifier dimmer, so that the dimming is realized.

Silicon controlled dimmers have been commonly used to dim incandescent lamps, and with the popularity of LED light sources, more and more LED driving circuits employ silicon controlled dimmers as dimming means. However, the system efficiency of the existing LED driving circuit is still to be improved, and it is difficult to be compatible with all the scr dimmers.

Referring to fig. 1, the unidirectional silicon controlled rectifier, also called a thyristor, has a structure that is shown in fig. 1-a and can be divided into four silicon regions P, N, P, N and A, K, G. The figure is cut in half as shown in fig. 1-b, and it can be easily understood that a unidirectional silicon controlled transistor is composed mainly of a PNP transistor and an NPN transistor as shown in fig. 1-c.

When the positive voltage V is applied to the anode-cathode (a-K), the transistor Q2 is turned on in the forward direction as long as the gate G is turned on to trigger the power supply Vg, the transistor Q2 is turned on at the moment Q1 just like a load connected to the collector of Q1 is turned on with the positive electrode of the power supply, and then Q1 is turned on under the pull current of Q2, at this time, since C is charged, even if the trigger power supply Vg of the gate is turned off, Q1 and Q2 can maintain the on state under the interaction, and Q1 and Q2 are turned off again only after the power supply voltage V becomes relatively small.

Compared with unidirectional thyristors, the bidirectional thyristors are in principle the biggest difference in that they can be turned on in two directions, and instead of having anode and cathode portions, they are represented by T1 and T2, the schematic structure is shown in fig. 3-a, if they are divided into fig. 3-b without considering the difference of G-level, it can be seen that two unidirectional thyristors are connected in opposite parallel, as shown in fig. 3-c.

Referring to fig. 4, fig. 4 discloses a schematic diagram of a scr dimmer. The silicon controlled dimmer turned on requires a large current, but maintains on without requiring a large current, and the dimmer turned off has a process requiring time according to the characteristics of the transistor, without abrupt change, as shown in table 1.

TABLE 1 silicon controlled dimmer on-off condition table

As shown in fig. 5, the conventional scr dimmer control circuit is controlled by a constant current IL, has no segmentation distinction, can adjust the size of IL only by adjusting a resistor R1, is difficult to be compatible with all dimmers, and has low efficiency. The conventional scheme drive waveforms are shown in fig. 6.

The existing scheme mainly has the following defects: (1) The efficiency is low, for example, when the triac dimmer is turned on, the bus voltage VBUS on the rectified dc bus exceeds the LED start-up voltage VLED, the operating current of the LED will generate enough current to normally turn on or maintain the triac dimmer, no bleed current is required, and the bleed current IL at this time will cause additional losses; (2) The bleed current can only be adjusted through R1, and R1 is fixed, and the current is not adjustable, and is difficult to be compatible with all dimmers.

In view of this, there is an urgent need to design an LED driving circuit so as to overcome the above-mentioned drawbacks of the existing LED driving circuit.

Disclosure of Invention

The technical problems to be solved by the invention are as follows: the self-adaptive circuit module can improve the efficiency of different systems to the greatest extent and is compatible with all silicon controlled dimmers.

Meanwhile, the invention provides an LED driving circuit with the silicon controlled rectifier light modulator, which can furthest improve the efficiency of different systems and is compatible with all the silicon controlled rectifier light modulators.

In addition, the invention also provides a driving method of the LED driving circuit with the silicon controlled rectifier light modulator, which can furthest improve the efficiency of different systems and is compatible with all the silicon controlled rectifier light modulators.

In order to solve the technical problems, the invention adopts the following technical scheme:

an adaptive circuit module for use in an LED driver circuit having a thyristor dimmer, the adaptive circuit module comprising:

the timer is used for detecting the starting time position of the silicon controlled rectifier dimmer;

The detector is coupled with the timer and the direct current bus and is used for detecting whether the silicon controlled rectifier dimmer is normally started or not;

and the controller is respectively coupled with the timer, the detector and the bleeder circuit and is used for adaptively controlling the bleeder current of the bleeder circuit according to the feedback results of the timer and the detector.

As a preferred scheme of the invention, the bleeder current comprises a pulse current, and the amplitude or pulse width or frequency of the pulse current is adjusted according to the information of whether the dimmer is normally started, so that the pulse current reaches the minimum current of the corresponding silicon controlled rectifier dimmer which is normally started; or alternatively

The discharging current comprises direct current, and the size of the direct current is adjusted according to the information of whether the dimmer is normally started or not, so that the direct current reaches the minimum current of the corresponding silicon controlled rectifier dimmer which is normally started.

As a preferred embodiment of the present invention, the controller uses pulse current control to adjust the amplitude or pulse width or frequency of the pulse current according to the information about whether the dimmer is normally turned on, and includes:

If the detector detects that the dimmer can be normally started in N continuous periods, the amplitude of the bleeder current is reduced according to a given proportion, or the pulse width is reduced or the frequency is reduced to reduce the average value of the bleeder current; then continuously detecting whether the dimmer can be normally started or not in N continuous periods; if the dimmer can be normally started in N continuous periods, continuously reducing the amplitude of the discharge current according to a given proportion or reducing the pulse width or reducing the frequency; and the like, until the detector detects that the dimmer cannot be normally started in N continuous periods, increasing the amplitude or pulse width or frequency of the discharge current to a value which can normally start the dimmer, and keeping unchanged, wherein the period is a period of the rectified power supply, N is more than or equal to 2, and N is a natural number;

If the detector detects that the dimmers cannot be normally turned on in N continuous periods, increasing the amplitude of the bleeder current or increasing the pulse width or increasing the frequency according to a given proportion to increase the average value of the bleeder current; then continuously detecting whether the dimmer can be normally started or not in N continuous periods; if the dimmer cannot be normally started in N continuous periods, continuously increasing the amplitude of the discharge current according to a given proportion or increasing the pulse width or increasing the frequency; and the like, the amplitude, pulse width and frequency of the bleeder current are kept unchanged until the detector detects that the dimmer can be normally started in N continuous periods.

As a preferred embodiment of the present invention, the controller uses dc current control to adjust the magnitude of dc current according to the result of detecting whether the dimmer is normally turned on, and includes:

under the given initial condition, if the dimmer can be normally started in N continuous periods, the current value is reduced according to the proportion set each time until the dimmer cannot be normally started, the current value is adjusted to the last value, then the current value is fixed and unchanged, the period is the period of the rectified power supply, and N is more than or equal to 2, and N is a natural number;

under the given initial conditions, if the dimmer cannot be normally turned on for N consecutive periods, the current value is increased in proportion to each setting until the current value is fixed after the dimmer is normally turned on.

As a preferred solution of the present invention, the adaptive circuit module further includes an LED on detection unit, configured to detect whether the LED lamp is turned on, and the controller controls according to feedback results of the LED on detection unit, the timer, and the detector:

If the light modulator is started at the moment, the LED lamp is started, and then no current is required to be discharged;

if the light modulator is started at the moment, the LED lamp is not started yet, and the starting position of the light modulator is more than 50% T, then no current is required to be discharged;

if the light modulator is turned on at the moment, the LED lamp is not turned on yet, and the position of the light modulator turned on is less than 50% T, then the current is required to be discharged.

As a preferable scheme of the invention, when the LED lamp is turned off and the time position exceeds 50% of T, a pulse current with low frequency or low pulse width is provided to ensure that the bus voltage can follow the change of the mains supply, and when the bus voltage is further reduced to a threshold voltage, a bleeder current is provided to reset the SCR dimmer.

As a preferred scheme of the invention, the LED on detection unit comprises a zeroth comparator, a first input end of the zeroth comparator is coupled with a reference voltage, and a second input end of the zeroth comparator is coupled with the constant current control circuit.

As a preferable mode of the invention, the controller comprises a fourth comparator, a fifth comparator, a sixth comparator, an SR trigger and a sixth capacitor; the controller is connected with a bleeder circuit, and the bleeder circuit comprises a first power amplifier, a first power tube and a first resistor;

the non-inverting input terminal of the fourth comparator 31 is connected to the first terminal of the sixth capacitor, the inverting input terminal of the fifth comparator 32, and the inverting input terminal of the sixth comparator 33, respectively;

The inverting input end of the fourth comparator is connected with the second reference voltage, and the output end of the fourth comparator is connected with the SR trigger; the second end of the sixth capacitor is grounded; the non-inverting input end of the fifth comparator is connected with a third reference voltage, and the output end of the fifth comparator is connected with an SR trigger;

the non-inverting input end of the sixth comparator is connected with a reference voltage, the output end of the sixth comparator is connected with an enabling port of the first power amplifier, the non-inverting input end of the first power amplifier is connected with a fourth reference voltage, the fourth reference voltage determines the amplitude of the discharge current, and the inverting input end of the first power amplifier is connected with the first end of the first resistor and the source electrode of the first power tube; the output end of the operational amplifier is connected with the grid electrode of the first power tube, the source electrode of the first power tube is connected with the bus voltage, and the second end of the first resistor is grounded;

Generating a triangular wave signal by charging and discharging the sixth capacitor, and then comparing the triangular wave signal with a reference voltage to generate a pulse signal, wherein the pulse signal controls the generation of a discharge current; wherein the pulse width is adjusted by adjusting the magnitude of the reference voltage; adjusting any one or more of the charge and discharge current of the triangular wave signal, the capacitance, the second reference voltage and the third reference voltage to adjust the frequency; and adjusting the fourth reference voltage to adjust the amplitude.

As a preferable scheme of the invention, the detector comprises a first switch, a second switches, a+1 capacitors, an AND gate and a comparators, wherein a is an integer greater than or equal to 1;

The first ends of the first switch and each second switch are respectively connected with the second end of the third resistor; the second ends of the first switches are respectively connected with the inverting input ends of the comparators, the second ends of the second switches are respectively connected with the non-inverting input ends of the different comparators, the second ends of the second switches are respectively connected with the first ends of the different capacitors, and the second ends of the capacitors are grounded; the output end of each comparator is connected with the input end of the AND gate, and the output end of the AND gate provides a detection result.

An LED driver circuit having a thyristor dimmer, the LED driver circuit comprising: the device comprises a silicon controlled rectifier dimmer, a rectifying circuit, a bleeder circuit, a constant current control circuit and a self-adaptive circuit module;

The self-adaptive circuit module is respectively connected with the rectifying circuit, the bleeder circuit and the constant current control circuit, the rectifying circuit is connected with the silicon controlled rectifier dimmer, the bleeder circuit is connected with the constant current control circuit, the constant current control circuit is connected with the LED lamp, and the self-adaptive circuit module is used for adaptively controlling the bleeder current in the bleeder circuit at least according to the starting information of the silicon controlled rectifier dimmer.

As a preferable scheme of the invention, the self-adaptive circuit module drives the silicon controlled rectifier dimmer through a preset pulse current, then detects whether the silicon controlled rectifier dimmer is normally started, and then appropriately adjusts the amplitude or pulse width or frequency of the pulse current according to the detection result so that the pulse current reaches the minimum current of the corresponding silicon controlled rectifier dimmer which is normally started;

Or the self-adaptive circuit module adopts a direct current control with an adjustable current value; and directly adjusting the magnitude of the discharge current according to the result of detecting whether the dimmer is normally started or not, so that the direct current reaches the minimum current of the corresponding silicon controlled rectifier dimmer which is normally started.

As a preferred embodiment of the present invention, the adaptive circuit module includes: the device comprises a detector, a timer and a controller, wherein the controller is respectively connected with the detector and the timer;

The detector is used for detecting whether the silicon controlled rectifier dimmer is normally started or not and sending a detection result to the controller;

The timer is used for detecting the starting position of the silicon controlled rectifier dimmer and feeding the acquired information back to the detector and the controller;

The controller is used for driving the silicon controlled rectifier dimmer through a pulse current with preset fixed amplitude, frequency and pulse width; and the pulse current is used for adjusting the amplitude or the pulse width or the frequency of the pulse current according to the detection result after the situation that the thyristor dimmer is not normally started is known, so that the pulse current reaches the minimum current of the corresponding thyristor dimmer which is normally started.

As a preferred scheme of the invention, the adaptive circuit module further comprises an LED on detection unit for detecting whether the LED lamp is on; the controller controls according to feedback results of the LED starting detection unit, the timer and the detector;

If the starting time of the silicon controlled rectifier dimmer is not yet started, and the counter knows that the starting time of the dimmer is less than 50% by T, the bleeder current of the starting interval of the silicon controlled rectifier dimmer is needed, wherein T is the period of the rectified power supply; providing an initialization current in an initial state, wherein the initialization current has set amplitude, frequency and pulse width;

The controller judges whether the dimmer can be normally started in N continuous periods according to the state of the dimmer detected by the detector; if yes, go to ①, otherwise go to ②;

① If the detector detects that the dimmer can be normally started in N continuous periods, the average value of the discharge current is reduced; then continuously detecting whether the dimmer can be normally started or not in N continuous periods; if the dimmer can be normally started in N continuous periods, continuously reducing the average value of the bleeder current; and the like, until the detector detects that the dimmer cannot be normally started in N continuous periods, increasing the average value of the discharge current to a value which can normally start the dimmer last time, and then keeping unchanged; wherein N is more than or equal to 2, and N is a natural number;

② If the detector detects that the dimmers cannot be normally started in N continuous periods, the average value of the discharge current is increased; then continuously detecting whether the dimmer can be normally started or not in N continuous periods; if the dimmer cannot be normally started in N continuous periods, continuously increasing the average value of the bleeder current; and the like, until the detector detects that the dimmer can be normally started in N continuous periods, the average value of the discharge current is kept unchanged.

As a preferred aspect of the present invention, the bleeder circuit is configured to provide a bleeder current; the bleeder circuit comprises a first power amplifier, a first power tube and a first resistor;

The output end of the first power amplifier is connected with the grid electrode of the first power tube, the drain electrode of the first power tube is connected with the bus, and the source electrode of the first power tube is respectively connected with the first end of the first resistor and the inverting input end of the first power amplifier; the non-inverting input end of the first power amplifier is connected with a first main reference voltage, the first power amplifier is connected with the controller, and the second end of the first resistor is connected with the constant current control circuit;

The constant current control circuit comprises a second power amplifier, a second power tube and a second resistor;

The output end of the second power amplifier is connected with the grid electrode of the second power tube, the drain electrode of the second power tube is connected with the second main reference voltage, and the source electrode of the second power tube is respectively connected with the first end of the second resistor, the inverting input end of the second power amplifier, the second end of the first resistor and the inverting input end of the zeroth comparator; the non-inverting input end of the second power amplifier is connected with a second main reference voltage, and the second end of the second resistor is grounded.

An LED driving method of an LED driving circuit having a silicon controlled dimmer, the LED driving method comprising:

Detecting the starting position of the silicon controlled rectifier dimmer;

Detecting whether the silicon controlled rectifier dimmer is normally started; and

And adaptively adjusting the bleeder current in the driving circuit according to the information of whether the silicon controlled rectifier dimmer is normally started or not and the starting position information of the silicon controlled rectifier dimmer.

As a preferable scheme of the invention, the controllable silicon dimmer is driven by a preset pulse current, whether the controllable silicon dimmer is normally started or not is detected, and the amplitude or the pulse width or the frequency of the pulse current is regulated according to the detection result, so that the pulse current reaches the minimum current of the corresponding controllable silicon dimmer which is normally started;

or adopting a direct current control with an adjustable current value; and directly adjusting the magnitude of the discharge current according to the result of detecting whether the dimmer is normally started or not, so that the direct current reaches the minimum current of the corresponding silicon controlled rectifier dimmer which is normally started.

As a preferred embodiment of the present invention, the triac dimmer is driven by a pulse current of a predetermined fixed amplitude, frequency and pulse width; after the silicon controlled rectifier dimmer is not normally started, the amplitude or the pulse width or the frequency of the pulse current is adjusted according to the detection result, so that the pulse current reaches the minimum current of the corresponding silicon controlled rectifier dimmer which is normally started.

The invention has the beneficial effects that: the self-adaptive circuit module, the LED driving circuit with the silicon controlled rectifier light modulator and the driving method thereof can be compatible with all the silicon controlled rectifier light modulator, and can control the starting of the silicon controlled rectifier light modulator according to the pulse currents with different amplitudes or different pulse widths generated by different silicon controlled rectifier light modulator, so that the efficiency of different systems can be improved to the greatest extent and all the silicon controlled rectifier light modulator can be compatible.

Drawings

Fig. 1 is a schematic diagram of a unidirectional thyristor structure.

Fig. 2 is a schematic diagram of the operation of the unidirectional silicon controlled rectifier.

Fig. 3 is a schematic diagram of a structure of a bidirectional thyristor.

Fig. 4 is a schematic diagram of a thyristor dimmer principle.

Fig. 5 is a schematic diagram of a conventional scr dimmer circuit.

Fig. 6 is a conventional driving waveform diagram of a conventional scr dimming circuit.

Fig. 7 is a circuit diagram of an LED driving circuit according to an embodiment of the present invention.

Fig. 8 is a timing diagram illustrating operation of an LED driving circuit according to an embodiment of the present invention.

Fig. 9 is a circuit schematic of a detector in an LED driving circuit according to an embodiment of the present invention.

Fig. 10 is a schematic diagram of a detector in an LED driving circuit according to an embodiment of the present invention.

Fig. 11 is a schematic diagram of a counter in an LED driving circuit according to an embodiment of the present invention.

Fig. 12 is a functional block diagram of a controller according to an embodiment of the present invention.

Fig. 13 is a flow chart of a controller for adjusting pulse current according to an embodiment of the invention.

Fig. 14 is a circuit diagram of a pulse width modulation circuit in an LED driving circuit according to an embodiment of the present invention.

Fig. 15 is a schematic diagram of a pulse width modulation circuit in an LED driving circuit according to an embodiment of the present invention.

Fig. 16 is a schematic diagram of a normal waveform detected by a detector in an LED driving circuit according to an embodiment of the present invention in the fifth embodiment.

Fig. 17 is a schematic diagram of an abnormal waveform detected by a detector in an LED driving circuit according to an embodiment of the present invention in the fifth embodiment.

Fig. 18 is a timing diagram of a controller in an adaptive circuit module according to an embodiment of the present invention.

Fig. 19 is a timing diagram of a controller in an adaptive circuit module according to an embodiment of the present invention.

Fig. 20 is a circuit schematic of a controller in an adaptive circuit module according to a sixth embodiment of the invention.

Detailed Description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

For a further understanding of the present invention, preferred embodiments of the invention are described below in conjunction with the examples, but it should be understood that these descriptions are merely intended to illustrate further features and advantages of the invention, and are not limiting of the claims of the invention.

The description of this section is intended to be illustrative of only a few exemplary embodiments and the invention is not to be limited in scope by the description of the embodiments. It is also within the scope of the description and claims of the invention to interchange some of the technical features of the embodiments with other technical features of the same or similar prior art.

The term "coupled" or "connected" in the specification includes both direct and indirect connections, such as through some active, passive, or electrically conductive medium. "plurality" means two or more.

Example 1

Referring to fig. 7, the present invention discloses an adaptive circuit module applied to an LED driving circuit with a scr dimmer, the adaptive circuit module includes: the timer 1, the detector 2 and the controller 3, wherein the controller 3 is respectively connected with the detector 2 and the timer 1.

The timer 1 is configured to detect a time position when the triac dimmer is turned on, and feed back the acquired information to the detector and the controller.

The detector 2 is coupled to the timer and the dc bus, and is configured to obtain a time position when the thyristor dimmer is turned on and a bus voltage VBUS, further detect whether the thyristor dimmer is normally turned on according to a time position when the thyristor dimmer is turned on and a variation trend of the bus voltage VBUS, and feed back a detected result to the controller.

The controller 3 is respectively connected with the detector 2 and the timer 1, and is used for adaptively controlling the bleeder current according to the information of whether the silicon controlled rectifier dimmer is normally started or not and the starting position information of the silicon controlled rectifier dimmer.

In one embodiment, the bleed current comprises a pulsed current comprising a continuous plurality of current pulses. The controller 3 adjusts the amplitude or the pulse width or the frequency of the pulse current according to the information of whether the dimmer is normally turned on, so that the pulse current reaches the minimum current of the corresponding silicon controlled rectifier dimmer which is normally turned on. Specifically, in one cycle, the controller 3 is configured to drive the triac dimmer by a pulse current of a predetermined fixed amplitude, frequency and pulse width; and the method can also be used for adjusting the amplitude or the pulse width or the frequency of the pulse current according to the detection result after knowing that the thyristor dimmer is not normally started, so that the pulse current reaches the minimum current of the corresponding thyristor dimmer which is normally started.

In addition, the adaptive circuit module may further include a zeroth comparator 4 for detecting whether the LED lamp 9 is turned on; the controller 3 controls the bleed current differently according to the different feedback results of the zeroth comparator 4, the timer 1 and the detector 2. Of course, the zeroth comparator 4 may also be part of the controller 3.

The working principle of the self-adaptive circuit module of the invention is as follows:

[ working time-series diagrams ]

Referring to FIG. 8 and Table 1, the working period T is divided into intervals of T0-T2, T2-T3, T3-T4, T4-T5, T5-T0; maintaining the T5 state in the interval of T0-T2; in the interval of T2-T3, the TRIAC is started; in the interval of T3-T4, the LED lamp is conducted; in the interval of T4-T5, the LED lamp is turned off; in the interval of T5-T0, VBUS < VF1.

In the sections T4-T5, the VBUS voltage can be ensured to be changed along with the mains supply, and the thyristor dimmer is not required to be completely started, so that pulse current with very low frequency and pulse width can be given.

In the sections T5 to T0, since VBUS is already low, it is necessary to turn on the scr dimmer completely, so that the scr dimmer can be reset at the normal zero crossing point of the bus voltage before the rectification, and therefore, the dimmer is driven with a large current to turn on.

Table 2 working time schedule

[ Detector ]

Referring to fig. 7, the adaptive circuit module further includes a voltage dividing resistor, where the voltage dividing resistor includes a third resistor R3 and a fourth resistor R4; the first end of the third resistor is connected with the direct current bus, the second end of the third resistor is respectively connected with the first ends of the detector 2, the timer 1 and the fourth resistor R4, and the second end of the fourth resistor R4 is grounded.

Referring to fig. 9 and 10, the detector 2 includes a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a first comparator 21, a second comparator 22, a third comparator 23, an and gate 24, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5.

The first end of the first switch S1, the first end of the second switch S2, the first end of the third switch S3, and the first end of the fourth switch S4 are respectively connected to the second end of the third resistor R3. The second end of the first switch S1 is connected to the first end of the second capacitor C2, the inverting input end of the first comparator 21, the inverting input end of the second comparator 22, and the inverting input end of the third comparator 23, respectively, and the second end of the second capacitor C2 is grounded. The second end of the second switch S2 is connected to the first end of the third capacitor C3 and the non-inverting input end of the first comparator 21, and the second end of the third capacitor C3 is grounded. The second end of the third switch S3 is connected to the first end of the fourth capacitor C4 and the non-inverting input end of the second comparator 22, and the second end of the fourth capacitor C4 is grounded. The second end of the fourth switch S4 is connected to the first end of the fifth capacitor C5 and the non-inverting input end of the third comparator 23, and the second end of the fifth capacitor C5 is grounded. The output end of the first comparator 21, the output end of the second comparator 22 and the output end of the third comparator 23 are respectively connected with the input end of the and gate 24.

When the dimmer is turned on, the first switch S1 is turned on, the voltage at this time is sampled, and then the first switch S1 is turned off. And (2) starting the S2 sampling voltage after delaying M% by T (T is the time of the whole period). And similarly, sampling is performed for N times (the sampling time point of each time cannot exceed 50% T), and if the voltage sampled later is higher than that of the first time, EN outputs a high potential to indicate that the silicon controlled rectifier dimmer is normally started. M is a constant greater than 0 and less than 10.

[ Timer ]

Referring to fig. 11, the timer 1 is used for detecting the on position of the dimmer and counting the number of cycles of VBUS. The on count of the dimmer is the time that the VBUS voltage is lower than VF 1. And VBUS jumps from below a certain threshold to above the threshold during this period.

[ Controller ]

Please refer to fig. 12 to 15. Fig. 12 shows a functional block diagram of a controller according to an embodiment of the invention. The controller receives the outputs of the timer, detector and comparator, determines the condition by the logic control circuit, and further provides and adjusts the VPWM signal by the pulse modulation circuit.

Fig. 13 shows a block flow diagram of a controller adjusting a pulse current according to an embodiment of the invention. Firstly, judging whether to adjust the pulse signal according to a signal that whether the LED is turned on when the silicon controlled rectifier dimmer is turned on and a signal that whether the time position of the turned-on time position of the silicon controlled rectifier dimmer exceeds 50% T. If the LED is not turned on when the silicon controlled rectifier dimmer is turned on and the time position of the turn-on is less than 50% T, pulse current is required to be provided, and the pulse current is regulated according to the condition of N periods; if the LED is not turned on when the triac dimmer is turned on and the on time position exceeds 50% T, or the LED is turned on when the triac dimmer is turned on, then no pulse current is required and the EN judgment period is not counted.

And then judging whether the silicon controlled rectifier dimmer is normally started in N periods according to a judging signal EN output by the detector, increasing or decreasing the bleeder current corresponding to the pulse current, and correspondingly adjusting the current pulse by adjusting the parameters of a pulse width modulation circuit in the controller.

Fig. 14 shows a circuit schematic of a pwm circuit in a controller according to an embodiment of the present invention, where the pwm circuit of the controller 3 includes a switch, a charging current source, a discharging current source, a fourth comparator 31, a fifth comparator 32, a sixth comparator 33, an SR flip-flop, a sixth capacitor C6, a first power transistor Q1, and a fifth resistor R5. The controller is connected with a bleeder circuit, and the bleeder circuit comprises a first power amplifier EA1, a first power tube Q1 and a first resistor R1.

The first end of the change-over switch can be switched between the charging current source and the discharging current source, and the output end of the SR trigger sends a signal to the change-over switch; the second end of the change-over switch is connected to the first end of the sixth capacitor, the non-inverting input end of the fourth comparator 31, the inverting input end of the fifth comparator 32 and the inverting input end of the sixth comparator 33, respectively.

The inverting input end of the fourth comparator 31 is connected with the second reference voltage VREF2, and the output end of the fourth comparator 31 is connected with the SR trigger; the second end of the sixth capacitor C6 is grounded; the non-inverting input end of the fifth comparator 32 is connected with the third reference voltage VREF3, and the output end of the fifth comparator 32 is connected with the SR trigger.

The non-inverting input end of the sixth comparator 33 is connected with a reference voltage VF2, the output end of the sixth comparator 33 is connected with an EN port of the first power amplifier EA1, the non-inverting input end of the first power amplifier EA1 is connected with a fourth reference voltage VREF4, the fourth reference voltage VREF4 determines the amplitude of the bleed current Ibld, and the inverting input end of the first power amplifier EA1 is connected with the first end of the first resistor R1 and the source electrode of the first power tube Q1; the output end of the operational amplifier is connected with the grid electrode of the first power tube Q1, the source electrode of the first power tube Q1 is connected with the busbar voltage VBUS, and the second end of the first resistor R1 is grounded.

Wherein VREF2 and VREF3 are reference voltages that generate a lower limit and an upper limit of the triangular wave signal, respectively; VF2 is the reference voltage that controls the pulse width; VREF4 in fig. 14 corresponds to Ref2 in fig. 7.

Pulse current modulation principle: with sufficient power to the capacitor, a triangular wave signal Vtrig is generated, which is then compared with a reference voltage VF2 to generate a pulse signal VPWM that controls the generation of current. The pulse width can be adjusted by adjusting the size of VF 2; the frequency can be adjusted by adjusting the charge and discharge current of the Vtrig, the capacitance, VREF2 and VREF 3; adjusting VREF4 may adjust the amplitude.

The control principle of the controller is as follows:

First case:

As shown in the timing chart of fig. 8, when the dimmer is turned on at a larger angle and the LED lamp is not turned on at time T2, bleed currents (i.e., the bleed current Ibld) of T2 to T3 are required. An initial state (referring to the time of power-on) provides an initial current, and the initial current has set amplitude, frequency and pulse width; the fixed amplitude, the fixed frequency and the pulse width are adjustable in the adjusting process, or the fixed frequency, the fixed pulse width and the amplitude are adjustable, or the fixed amplitude, the fixed pulse width and the frequency are adjustable.

1. If the EN output is high for N consecutive periods, the amplitude is reduced or the pulse width is reduced or the frequency is reduced according to a given proportion; then continuing to detect whether EN is high or not in N periods; if the pulse width is always high, continuing to reduce the amplitude or the pulse width or the frequency according to a given proportion; similarly, the amplitude or pulse width or frequency is increased back to the last value until EN goes low and then remains unchanged.

2. If EN is not all high for N consecutive periods, increasing the amplitude or increasing the pulse width or increasing the frequency by a given ratio; then continuing to detect whether EN is high or not in N periods; if not, continuing to increase the amplitude or the pulse width or the frequency according to the given proportion; and so on, the amplitude, pulse width and frequency remain unchanged until the EN output is high.

Second case:

Referring to fig. 18, at time T2 when the dimmer is turned on, VBUS voltage is already higher than the LED lamp turn-on voltage, ILED can act as Bleed current, the dimmer can be kept on normally, and Bleed current of T2-T3 is not needed.

Third case:

referring to fig. 19, the time T2 when the dimmer is turned on exceeds 50% T, and the VBUS voltage is already lower than the LED lamp turn-on voltage, and the LED is turned off without the Bleed current of the T2-T3 segments.

Example two

Referring to fig. 7, the present invention discloses an adaptive circuit module applied to an LED driving circuit with a scr dimmer, the adaptive circuit module includes: the detector 2, the timer 1 and the controller 3, wherein the controller 3 is respectively connected with the detector 2 and the timer 1.

The detector 2 is configured to detect whether the scr dimmer is normally turned on, and feed back the detected result to the controller 3. The timer 1 is configured to detect an on position after the triac dimmer is turned on, and feed back acquired information to the detector 2 and the controller 3; the counter 1 is also used to count the number of cycles of VBUS.

The controller 3 is configured to adaptively control the bleed current according to the information about whether the triac dimmer is normally turned on and the triac dimmer on position time information. The controller 3 drives the triac dimmer by a predetermined pulse current (having a set amplitude, frequency and pulse width); and the pulse current modulation circuit is also used for adjusting the amplitude or the pulse width or the frequency of the pulse current according to the detection result after knowing that the thyristor dimmer is not normally started (the pulse current modulation circuit of the controller realizes the function) so that the pulse current reaches the minimum current of the corresponding thyristor dimmer which is normally started.

In addition, the adaptive circuit module further comprises a zeroth comparator 4 for detecting whether the LED lamp is turned on; the non-inverting input end of the zeroth comparator 4 is connected with a third main reference voltage Ref3, and the inverting input end of the zeroth comparator is connected with a constant current control circuit; the third main reference voltage Ref3 is used for detecting whether the LED lamp is normally turned on or not.

The LED on detection unit may take other forms besides the zeroth comparator, such as a current detection mode, a current sensor, other types of current detection circuits, and the like.

The controller 3 controls the bleed current differently according to the different feedback results of the zeroth comparator 4, the timer 1 and the detector 2. Of course, the zeroth comparator 4 may also be part of the controller.

The controller 3 makes different control processes according to different feedback results of the zeroth comparator 4, the timer 1 and the detector 2;

(1) Referring to fig. 18, according to the feedback result of the zeroth comparator 4, if the LED lamp is already turned on at the moment of turning on the dimmer, then there is no need to adjust the bleed current Ibld;

(2) Referring to fig. 19, according to the feedback result of the zeroth comparator 4, if the LED lamp is not turned on at the time of turning on the dimmer, and the counter knows that the time of turning on the dimmer has exceeded 50% T, it indicates that the voltage at the time of turning on the dimmer is insufficient to turn on the LED lamp, so that the bleed current Ibld does not need to be adjusted;

(3) Referring to fig. 8, according to the feedback result of the zeroth comparator 4, if the triac dimmer is turned on at time T2, the LED lamp is not turned on yet, and the counter knows that the time of the dimmer is less than 50% T, then the bleeder current Ibld in the triac dimmer turn-on interval T2-T3 is needed; an initial state (referring to the time of power-on) provides an initial current, and the initial current has set amplitude, frequency and pulse width; the fixed amplitude, the fixed frequency and the pulse width are adjustable in the adjusting process, or the fixed frequency, the fixed pulse width and the amplitude are adjustable, or the fixed amplitude, the fixed pulse width and the frequency are adjustable.

① If the detector detects that the dimmer is normally on in N continuous periods, the amplitude of the bleeding current Ibld is reduced or the pulse width is reduced or the frequency is reduced according to a given proportion (the given proportion can be a set proportion or value, or can be an uncertain value, a proportion or even a random value within a certain range) so as to reduce the average value of the bleeding current Ibld; then continuously detecting whether the dimmer can be normally started or not in N continuous periods; if the dimmer can be normally started in N continuous periods, continuously reducing the amplitude of the release current Ibld or reducing the pulse width or reducing the frequency according to a given proportion; and the like, until the detector detects that the dimmer cannot be normally started in N continuous periods, increasing the amplitude or pulse width or frequency of the release current Ibld to a value which can normally start the dimmer last time, and then keeping unchanged; n is more than or equal to 2, and N is a natural number;

② If the detector detects that the dimmer cannot be normally turned on in N continuous periods, the amplitude of the bleeding current Ibld is increased or the pulse width is increased or the frequency is increased according to a given proportion (the given proportion or the preset value, the preset proportion or even a random value within a certain range) to increase the average value of the bleeding current Ibld; then continuously detecting whether the dimmer can be normally started or not in N continuous periods; if the dimmer cannot be normally started in N continuous periods, continuously increasing the amplitude of the release current Ibld or increasing the pulse width or increasing the frequency according to a given proportion; and the like, the amplitude, pulse width and frequency of the release current Ibld are kept unchanged until the detector detects that the dimmer can be normally started in N continuous periods.

Specifically, the control mode of the controller includes:

(1) Referring to fig. 18, if the bus voltage VBUS is higher than the LED lamp turn-on voltage at time T2 when the scr dimmer is turned on, the current ILED flowing through the LED lamp can be used as the bleed current Ibld, and the dimmer can be kept normally turned on, so that the bleed current Ibld in the interval of T2 to T3 is not required;

(2) Referring to fig. 19, if the time T2 when the scr dimmer is turned on exceeds 50% T, and the bus voltage VBUS is already lower than the LED lamp turn-on voltage, the LED is turned off, and no bleed current Ibld in the interval of T2 to T3 is needed;

(3) Referring to fig. 8, if the opening angle of the scr dimmer is larger, the LED lamp is not turned on at the time T2, and then a bleed current Ibld (Bleed current) from T2 to T3 is required; an initial state (referring to the time of power-on) provides an initial current, and the initial current has set amplitude, frequency and pulse width; the fixed amplitude, the fixed frequency and the pulse width are adjustable in the adjusting process, or the fixed frequency, the fixed pulse width and the amplitude are adjustable, or the fixed amplitude, the fixed pulse width and the frequency are adjustable;

① If the detector detects that the dimmer is normally on (EN outputs are all high) for N consecutive periods, then the amplitude is reduced or the pulse width is reduced or the frequency is reduced by a given ratio; then continue to check for N cycles, whether the dimmer is normally on (whether the EN output is all high); if the dimmer is normally on (EN outputs are all high), continuing to decrease the amplitude or decrease the pulse width or decrease the frequency by a given ratio; and so on, until the detector detects that the dimmer cannot be normally turned on (the EN outputs are not all high), the amplitude or pulse width or frequency is increased back to the last value, and then remains unchanged; n is more than or equal to 2, and N is a natural number;

② If the detector detects that the dimmer cannot be normally turned on (EN is not all high) for N consecutive periods, increasing the amplitude or increasing the pulse width or increasing the frequency by a given ratio; then continue to check for N cycles, whether the dimmer is normally on (whether the EN output is all high); if the dimmer is not normally on (EN is not all high), then continuing to increase the amplitude or increase the pulse width or increase the frequency by a given ratio; and so on, until the detector detects that the dimmer is normally on (EN output is high), the amplitude, pulse width and frequency are kept unchanged;

Wherein, the working period T is divided into sections of T0-T2, T2-T3, T3-T4, T4-T5 and T5-T0; maintaining the T5 state in the interval of T0-T2; in the interval of T2-T3, the silicon controlled rectifier dimmer is started; in the interval of T3-T4, the LED lamp is conducted; in the interval of T4-T5, the LED lamp is turned off; in the interval of T5-T0, VBUS < VF1; VF1 is a set detection voltage point;

in the interval of T4-T5, only the busbar voltage VBUS is required to be ensured to be capable of changing along with the mains supply, the silicon controlled rectifier dimmer is not required to be completely started, and pulse current with very low frequency and pulse width can be provided.

In the interval from T5 to T0, since the bus voltage VBUS is already low, the thyristor dimmer needs to be turned on completely, so that the unrectified bus voltage can reset the thyristor dimmer at the normal zero crossing point, and a large current is required to drive the dimmer to turn on.

Referring to fig. 14, the controller 3 includes a switch, a charging current source, a discharging current source, a fourth comparator 31, a fifth comparator 32, a sixth comparator 33, an SR flip-flop, a sixth capacitor C6, a first power transistor Q1, and a fifth resistor R5.

The inverting input end of the fourth comparator 31 is connected with VREF2, and the output end of the fourth comparator 31 is connected with an SR trigger; the second end of the sixth capacitor C6 is grounded; the non-inverting input end of the fifth comparator 32 is connected with VREF3, and the output end of the fifth comparator 32 is connected with an SR trigger.

The non-inverting input end of the sixth comparator 33 is connected with the reference voltage VF2, the output end of the sixth comparator 33 is connected with the EN port of the operational amplifier (i.e. the first power amplifier EA1 of the bleeder circuit), the non-inverting input end of the operational amplifier is connected with VREF4, the inverting input end of the operational amplifier is connected with the first end of the first resistor R1 and the source electrode of the first power tube Q1; the output end of the operational amplifier is connected with the grid electrode of the first power tube Q1, the source electrode of the first power tube Q1 is connected with the busbar voltage VBUS, and the second end of the first resistor R1 is grounded.

Generating a triangular wave signal Vtrig by charging and discharging a capacitor, and then comparing the triangular wave signal Vtrig with a reference voltage VF2 to generate a pulse signal VPWM, wherein the pulse signal VPWM controls the generation of current; the pulse width is adjusted by adjusting the magnitude of the reference voltage VF 2; the frequency can be adjusted by adjusting the charge and discharge current of the triangular wave signal Vtrig, the capacitance, VREF2 and VREF 3; adjusting VREF4 can adjust the amplitude.

As shown in fig. 7, the adaptive circuit module further includes a voltage dividing resistor, where the voltage dividing resistor includes a third resistor R3 and a fourth resistor R4; the first end of the third resistor is connected with the direct current bus, the second end of the third resistor is respectively connected with the first ends of the detector, the timer and the fourth resistor R4, and the second end of the fourth resistor R4 is grounded.

The detector 2 includes a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a first comparator, a second comparator, a third comparator, an and gate, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5.

The first end of the first switch S1, the first end of the second switch S2, the first end of the third switch S3, and the first end of the fourth switch S4 are respectively connected to the second end of the third resistor R3. The second end of the first switch S1 is respectively connected with the first end of the second capacitor C2, the inverting input end of the first comparator, the inverting input end of the second comparator and the inverting input end of the third comparator, and the second end of the second capacitor C2 is grounded. The second end of the second switch S2 is connected to the first end of the third capacitor C3 and the non-inverting input end of the first comparator, and the second end of the third capacitor C3 is grounded. The second end of the third switch S3 is respectively connected with the first end of the fourth capacitor C4 and the non-inverting input end of the second comparator, and the second end of the fourth capacitor C4 is grounded. The second end of the fourth switch S4 is connected to the first end of the fifth capacitor C5 and the non-inverting input end of the third comparator, and the second end of the fifth capacitor C5 is grounded. The output end of the first comparator, the output end of the second comparator and the output end of the third comparator are respectively connected with the input end of the AND gate.

Example III

Referring to fig. 7, the present invention discloses an LED driving circuit with a scr dimmer, the LED driving circuit comprising: the self-adaptive circuit comprises a silicon controlled rectifier dimmer 8, a rectifying circuit 7, a bleeder circuit 5, a constant current control circuit 6 and a self-adaptive circuit module.

The function of the silicon controlled dimmer 8 is to cut off a point of the normal sine wave to adjust the brightness of the following LED lamp; the rectifier circuit 7 functions to convert the alternating current into direct current; the bleeder circuit 5 and the constant current control circuit 6 are the same in structure, and a stable current source is generated by using the power amplifier.

The self-adaptive circuit module is respectively connected with the rectifying circuit 7, the bleeder circuit 5 and the constant current control circuit 6, and the rectifying circuit 7 is connected with the silicon controlled rectifier dimmer 8. The self-adaptive circuit module drives the silicon controlled rectifier dimmer 8 through a preset pulse current (an initial value of the pulse current is provided by a pulse modulation circuit in the controller, and a pulse signal is output by the pulse modulation circuit after power-on), then whether the silicon controlled rectifier dimmer is normally started or not is detected, and then the amplitude or pulse width or frequency of the pulse current is properly adjusted according to a detection result (realized by the pulse current modulation circuit), so that the pulse current reaches the minimum current corresponding to the normally started silicon controlled rectifier dimmer.

The adaptive circuit module includes: the detector 2, the timer 1 and the controller 3, wherein the controller 3 is respectively connected with the detector 2 and the timer 1. The detector 2 is used for detecting whether the silicon controlled rectifier dimmer is normally started or not, and sending a detection result to the controller 3; the timer 1 is used for detecting the starting position of the silicon controlled rectifier dimmer and feeding back the acquired information to the detector 2 and the controller 3; the controller 3 is used for driving the silicon controlled rectifier dimmer 8 through a pulse current with preset fixed amplitude, frequency and pulse width; and the pulse current is used for adjusting the amplitude or the pulse width or the frequency of the pulse current according to the detection result after the situation that the thyristor dimmer is not normally started is known, so that the pulse current reaches the minimum current corresponding to the normally started thyristor dimmer 8.

In addition, the adaptive circuit module further comprises a zeroth comparator 4 for detecting whether the LED lamp is turned on; the non-inverting input end of the zeroth comparator 4 is connected with a third main reference voltage Ref3, and the inverting input end of the zeroth comparator 4 is connected with a constant current control circuit 6; the third main reference voltage Ref3 is used for detecting whether the LED lamp is normally turned on or not.

The specific processing procedure of the adaptive circuit module can be referred to the description of the first embodiment.

The bleeder circuit 5 includes a first power amplifier EA1, a first power tube Q1, and a first resistor R1. The output end of the first power amplifier EA1 is connected with the grid electrode of the first power tube Q1, the drain electrode of the first power tube Q1 is connected with a bus, and the source electrode of the first power tube Q1 is respectively connected with the first end of the first resistor R1 and the inverting input end of the first power amplifier EA 1; the non-inverting input end of the first power amplifier EA1 is connected with a first main reference voltage Ref1, the first power amplifier EA1 is connected with the controller, and the second end of the first resistor R1 is connected with the constant current control circuit. The first main reference voltage Ref1 is a reference voltage that controls the bleed current.

The constant current control circuit 6 comprises a second power amplifier EA2, a second power tube Q2 and a second resistor R2. The output end of the second power amplifier EA2 is connected with the grid electrode of the second power tube Q2, the drain electrode of the second power tube Q2 is connected with the second main reference voltage Ref2, and the source electrode of the second power tube Q2 is respectively connected with the first end of the second resistor R2, the inverting input end of the second power amplifier EA2, the second end of the first resistor R1 and the inverting input end of the zeroth comparator; the non-inverting input end of the second power amplifier EA2 is connected with a second main reference voltage, and the second end of the second resistor R2 is grounded. The second main reference voltage Ref2 is a reference voltage controlling the LED lamp current.

The first end of the rectifying circuit 7 is connected with the silicon controlled rectifier dimmer, the second end of the rectifying circuit is respectively connected with the first end of the third resistor R3, the drain electrode of the first power tube Q1 and the positive electrode of the first diode D1, and the third end of the rectifying circuit is grounded;

The timer 1 is respectively connected with the second end of the third resistor R3 and the first end of the fourth resistor R4, and is connected with the controller; the detector is respectively connected with the second end of the third resistor R3 and the first end of the fourth resistor R4, and is connected with the controller; the second end of the fourth resistor R4 is grounded.

In this embodiment, the LED driving circuit further includes a first diode D1 and a first capacitor C1; the negative electrode of the first diode D1 is connected with the first end of the first capacitor C1 and the positive electrode of the LED lamp, and the drain electrode of the second power tube Q2 is connected with the second end of the first capacitor C1 and the negative electrode of the LED lamp respectively. The first diode D1 is a diode for preventing reverse current flow, and the first capacitor C1 is for reducing current ripple of the LED lamp. Of course, the first diode D1 and the first capacitor C1 are not essential to the present invention, and may be replaced by other circuits.

The invention also discloses an LED driving method of the LED driving circuit with the silicon controlled rectifier, which comprises the following steps: the method comprises the steps of driving the silicon controlled rectifier dimmer through a preset pulse current, detecting whether the silicon controlled rectifier dimmer is normally started or not, and adjusting the amplitude, the pulse width or the frequency of the pulse current according to the detection result so that the pulse current reaches the minimum current corresponding to the normally started silicon controlled rectifier dimmer. The specific driving method of the present invention can be found in the description of the driving circuit above.

Example IV

The difference between the present embodiment and the third embodiment is that in the present embodiment, the first diode D1 and the first capacitor C1 may be replaced by a strobe removal circuit.

Example five

The difference between the present embodiment and the first, second and third embodiments is that in the present embodiment, the detector may adopt other manners. As shown in fig. 16 and 17, the number of rising edges or falling edges in i cycles is counted and then compared with the number of cycles obtained by the counter. If the two types of the light sources are equal, the light modulator is considered to be normally started; if the number of rising edges or falling edges is more, the dimmer is opened more, and the dimmer does not work normally.

Example six

The difference between the present embodiment and the first, second and third embodiments is that in the present embodiment, pulse current control may not be adopted, and the controller is configured to control with a dc current having an adjustable current value, that is, to use the dc current as the bleed current, and directly adjust the magnitude of the bleed current Ibld according to the result of detecting whether the dimmer is normally turned on, so that the dc current reaches the minimum current corresponding to the normally turned on scr dimmer.

The controller adopts the direct current control with adjustable current value, and directly adjusts the magnitude of the discharge current Ibld current according to the result of detecting whether the dimmer is normally started, and the two conditions are as follows:

(1) Under the given initial condition, if the dimmer can be normally started, the current value is reduced according to the proportion set each time until the dimmer cannot be normally started, the current value is adjusted to the last value, and then the current value is fixed;

(2) Under the given initial conditions, if the dimmer cannot be normally turned on, the current value is increased in proportion to each setting until the value is fixed after the dimmer is normally turned on.

Referring to fig. 20, the controller includes a first operational amplifier, a third power tube, a plurality of switches (switches S1 to Sn), and a plurality of resistors; the non-inverting input end of the first operational amplifier is connected with a fifth reference voltage VREF5, the inverting input end of the first operational amplifier is connected with the source electrode of the third power tube, and the output end of the first operational amplifier is connected with the grid electrode of the third power tube.

The fifth reference voltage VREF5 (which is a fixed reference voltage) generates a plurality of equally decreasing reference voltages through the first operational amplifier, and then gates the required reference voltages with the switches S1 to Sn as the fourth reference voltage VREF4.

The S1-Sn switches are controlled by signals generated by the controller, and the reference voltages required by gating are sequentially increased or decreased.

Example seven

The difference between the present embodiment and the first and second embodiments is that in the present embodiment, the number of switches and comparators may be selected according to the needs; the detector comprises a first switch S1, a second switches, a+1 capacitors, an AND gate and a comparators, wherein a is an integer greater than or equal to 1. And performing AND logic on the output signals of the a comparators. In the first embodiment, a is 3, and a may have other values, such as 1, 2, 4, 5, 10, etc.

The first ends of the first switch S1 and the second switches are respectively connected with the second end of the third resistor R3; the second ends of the first switches S1 are respectively connected with the inverting input ends of the comparators, the second ends of the second switches are respectively connected with the non-inverting input ends of the different comparators, the second ends of the second switches are respectively connected with the first ends of the different capacitors, and the second ends of the capacitors are grounded; the output end of each comparator is connected with the input end of the AND gate.

Example eight

The difference between the present embodiment and the first and second embodiments is that in the present embodiment, the comparator in the adaptive circuit module may be used as a part of the controller (in the second embodiment, the comparator is not a part of the controller but is separately present).

In summary, the adaptive circuit module, the LED driving circuit with the thyristor dimmer and the driving method thereof provided by the invention can be compatible with all the thyristor dimmers, and can control the turn-on of the thyristor dimmers according to the pulse currents with different amplitudes, different pulse widths or different frequencies generated by different thyristor dimmers, so that the efficiency of different systems can be improved to the greatest extent and all the thyristor dimmers can be compatible.

The description and applications of the present invention herein are illustrative and are not intended to limit the scope of the invention to the embodiments described above. Variations and modifications of the embodiments disclosed herein are possible, and alternatives and equivalents of the various components of the embodiments are known to those of ordinary skill in the art. It will be clear to those skilled in the art that the present invention may be embodied in other forms, structures, arrangements, proportions, and with other assemblies, materials, and components, without departing from the spirit or essential characteristics thereof. Other variations and modifications of the embodiments disclosed herein may be made without departing from the scope and spirit of the invention.

Claims

1. An adaptive circuit module for use in an LED driver circuit having a thyristor dimmer, the adaptive circuit module comprising:

the controller is respectively coupled with the timer, the detector and the bleeder circuit and is used for adaptively controlling the bleeder current of the bleeder circuit according to the feedback results of the timer and the detector;

The self-adaptive circuit module further comprises an LED opening detection unit for detecting whether the LED lamp is opened, and the controller controls according to feedback results of the LED opening detection unit, the timer and the detector:

2. The adaptive circuit module of claim 1, wherein:

The bleeder current comprises a pulse current, and the amplitude or pulse width or frequency of the pulse current is adjusted according to the information of whether the dimmer is normally started, so that the pulse current reaches the minimum current of the corresponding silicon controlled rectifier dimmer which is normally started; or alternatively

3. The adaptive circuit module of claim 2, wherein the controller adjusts the amplitude or the pulse width or the frequency of the pulse current according to the information of whether the dimmer is normally turned on using pulse current control, comprising:

4. The adaptive circuit module of claim 2, wherein the controller uses dc current control to adjust the magnitude of the dc current based on the result of detecting whether the dimmer is normally on, comprising:

5. The adaptive circuit module of claim 1, wherein when the LED lamp is turned off and the time position exceeds 50% T, a low frequency or low pulse width pulse current is provided to ensure that the bus voltage follows the mains voltage change, and when the bus voltage is further reduced to a threshold voltage, a bleed current is provided to reset the scr dimmer.

6. The adaptive circuit module of claim 1, wherein:

the LED turn-on detection unit comprises a zeroth comparator, a first input end of the zeroth comparator is coupled with a reference voltage, and a second input end of the zeroth comparator is coupled with the constant current control circuit.

7. The adaptive circuit module of claim 1, wherein:

The controller comprises a change-over switch, a charging current source, a discharging current source, a fourth comparator, a fifth comparator, a sixth comparator, an SR trigger and a sixth capacitor; the controller is connected with a bleeder circuit, and the bleeder circuit comprises a first power amplifier, a first power tube and a first resistor;

the first end of the change-over switch can be switched between the charging current source and the discharging current source, and the output end of the SR trigger sends a signal to the change-over switch; the second end of the change-over switch is respectively connected with the first end of the sixth capacitor, the non-inverting input end of the fourth comparator, the inverting input end of the fifth comparator and the inverting input end of the sixth comparator;

8. The adaptive circuit module of claim 7, wherein:

the detector comprises a first switch, a second switches, a+1 capacitors, an AND gate and a comparators, wherein a is an integer greater than or equal to 1;

9. An LED driving circuit with a thyristor dimmer, the LED driving circuit comprising: the device comprises a silicon controlled rectifier dimmer, a rectifying circuit, a bleeder circuit, a constant current control circuit and a self-adaptive circuit module;

The self-adaptive circuit module is respectively connected with the rectifying circuit, the bleeder circuit and the constant current control circuit, the rectifying circuit is connected with the silicon controlled rectifier dimmer, the bleeder circuit is connected with the constant current control circuit, the constant current control circuit is connected with the LED lamp, and the self-adaptive circuit module is used for adaptively controlling the bleeder current in the bleeder circuit at least according to the starting information of the silicon controlled rectifier dimmer;

the adaptive circuit module includes:

The controller is respectively coupled with the timer, the detector and the bleeder circuit and is used for adaptively controlling the bleeder current of the bleeder circuit according to the feedback results of the timer and the detector; and

The LED opening detection unit is used for detecting whether the LED lamp is opened or not, and the controller controls according to feedback results of the LED opening detection unit, the timer and the detector:

10. The LED driver circuit with a thyristor dimmer of claim 9, wherein: the self-adaptive circuit module drives the silicon controlled rectifier dimmer through a preset pulse current, then detects whether the silicon controlled rectifier dimmer is normally started, and then appropriately adjusts the amplitude or pulse width or frequency of the pulse current according to the detection result so that the pulse current reaches the minimum current for normally starting the corresponding silicon controlled rectifier dimmer;

11. The LED driver circuit with a thyristor dimmer of claim 9, wherein:

the adaptive circuit module includes: the device comprises a detector, a timer and a controller, wherein the controller is respectively connected with the detector and the timer;

12. The LED driver circuit with a thyristor dimmer of claim 11, wherein:

The self-adaptive circuit module further comprises an LED on detection unit for detecting whether the LED lamp is on or not; the controller controls according to feedback results of the LED starting detection unit, the timer and the detector;

13. The LED driver circuit with a thyristor dimmer of claim 9, wherein:

The bleeder circuit is used for providing bleeder current; the bleeder circuit comprises a first power amplifier, a first power tube and a first resistor;

The output end of the first power amplifier is connected with the grid electrode of the first power tube, the drain electrode of the first power tube is connected with the bus, and the source electrode of the first power tube is respectively connected with the first end of the first resistor and the inverting input end of the first power amplifier; the non-inverting input end of the first power amplifier is connected with a first main reference voltage, the first power amplifier is connected with a controller, and the second end of the first resistor is connected with the constant current control circuit;

14. An LED driving method of an LED driving circuit having a silicon controlled dimmer, the method comprising:

Detecting the starting position of the silicon controlled rectifier dimmer;

Detecting whether the silicon controlled rectifier dimmer is normally started;

Adaptively adjusting the bleeder current in the driving circuit according to the information of whether the silicon controlled rectifier dimmer is normally started or not and the starting position information of the silicon controlled rectifier dimmer; and

Detecting whether the LED lamp is started or not, and controlling according to detection results of whether the LED lamp is started or not, the starting position of the silicon controlled rectifier dimmer and whether the silicon controlled rectifier dimmer is normally started or not;

15. The LED driving method according to claim 14, wherein:

driving the silicon controlled rectifier dimmer through a preset pulse current, detecting whether the silicon controlled rectifier dimmer is normally started or not, and adjusting the amplitude or pulse width or frequency of the pulse current according to the detection result so that the pulse current reaches the minimum current for normally starting the corresponding silicon controlled rectifier dimmer;

16. The LED driving method according to claim 15, wherein:

Driving the thyristor dimmer by a pulse current of a predetermined fixed amplitude, frequency and pulse width; after the silicon controlled rectifier dimmer is not normally started, the amplitude or the pulse width or the frequency of the pulse current is adjusted according to the detection result, so that the pulse current reaches the minimum current of the corresponding silicon controlled rectifier dimmer which is normally started.