CN208623951U - A kind of phase-cut dimming system - Google Patents

Abstract

The utility model discloses a kind of phase-cut dimming systems.Phase-cut dimming system includes phase-cut dimmer, the first rectification circuit, voltage conversion circuit, the second rectification circuit, cut phase waveforms detection and conversion circuit, control circuit and DC converting circuit；Control circuit is used to export corresponding control signal according to second signal, and the frequency for controlling signal is greater than the frequency of second signal, and outputs control signals to the control terminal of DC converting circuit；The input terminal of DC converting circuit is electrically connected with the primary side of voltage conversion circuit；DC converting circuit is used to export corresponding electric current according to control signal.Realize the light emission luminance of control LED light, to avoid the control terminal for the DC converting circuit for using photoelectrical coupler that the first signal of side three times is coupled to secondary side, the peripheral circuit being used cooperatively with photoelectrical coupler is avoided simultaneously, the occupied space of phase-cut dimming system is reduced, while reducing the cost of phase-cut dimming system.

Description

A kind of phase-cut dimming system

Technical field

The utility model embodiment is related to LED light regulating technology field more particularly to a kind of phase-cut dimming system.

Background technique

It is energy-efficient to require higher and higher, therefore the lighting method of LED light under global energy and the dual-pressure of environmental protection Traditional incandescent lamp will be replaced.

There are mainly two types of the dimming modes that LED illumination uses, PWM light modulation and DC voltage simulation light modulation.In PWM light modulation In the process, LED is with high speed switch, and can change its light emission luminance by changing the pulsewidth of high-speed switch pulse.For Realization high power factor does not have electrolytic capacitor in PWM light adjusting circuit, and LED shines a bigger starting voltage (about in 2V or more), therefore in PWM light adjusting circuit, there is the region for being less than starting voltage between two sine waves, LED is not It shines, therefore LED is caused to flash.In order to remove the stroboscopic problem of LED, inverse-excitation type is used in light adjusting circuit under normal circumstances (flyback) converter directly detects the power frequency waveform of exchange input using primary side, reuses photoelectrical coupler coupling It is controlled to secondary side.It is this removal LED stroboscopic problem circuit relative cost it is higher, and volume take up space greatly it is more, The light adjusting system design limited for space and cost is very unfavorable, such as the built-in no stroboscopic two-stage dimming drive power of fluorescent tube Design.

Utility model content

The utility model provides a kind of phase-cut dimming system and is dropped simultaneously with reducing the occupied space of phase-cut dimming system The cost of undercut phase light adjusting system.

In a first aspect, the utility model embodiment provides a kind of phase-cut dimming system, including it is phase-cut dimmer, first whole Current circuit, voltage conversion circuit, the second rectification circuit, cut phase waveforms detection and conversion circuit, control circuit and direct current conversion electricity Road；

The input terminal input ac power of the phase-cut dimmer, the output end of the phase-cut dimmer and described first whole The input terminal of current circuit is electrically connected；

The voltage conversion circuit includes the primary side and primary side of electrical isolation, the primary side and first rectification The output end of circuit is electrically connected, and the voltage conversion circuit is for being converted to the direct current signal that first rectification circuit exports First signal；

The input terminal of the cut phase waveforms detection and conversion circuit is electrically connected with the primary side of the voltage conversion circuit, institute The output end for stating cut phase waveforms detection and conversion circuit is electrically connected with the input terminal of the control circuit；The cut phase waveforms detection It is used to the first signal of the primary side being converted to second signal with conversion circuit, the chopping frequency of the second signal is less than The chopping frequency of first signal；

The output end of the control circuit is electrically connected with the control terminal of the DC converting circuit；The control circuit is used for Corresponding control signal is exported according to the second signal, the frequency of the control signal is greater than the frequency of the second signal, And export the control terminal of the control signal to the DC converting circuit；

The input terminal of second rectification circuit is electrically connected with the primary side of the voltage conversion circuit, the direct current conversion The input terminal of circuit is electrically connected with the output end of second rectification circuit；The DC converting circuit is used for according to the control Signal exports corresponding electric current.

Specifically, the cut phase waveforms detection and conversion circuit include rectification unit and charge-discharge control unit, described whole Flow input terminal of the first end of unit as the cut phase waveforms detection and conversion circuit, the second end of the rectification unit and institute State the first end electrical connection of charge-discharge control unit, the second end ground connection of the charge-discharge control unit, the charge and discharge control Output end of the output end of unit as the cut phase waveforms detection and conversion circuit.

Specifically, the charge-discharge control unit includes first capacitor, first resistor and second resistance；

The first end of the first capacitor is electrically connected with the first end of the first resistor, the second end of the first capacitor It is electrically connected with the second end of the second resistance, the second end of the first resistor and the first end of the second resistance are electrically connected It connects；Output end of the second end of the first resistor as the charge-discharge control unit, the second termination of the second resistance Ground.

Specifically, the charge and discharge time of the first capacitor is greater than the first signal of primary side of the voltage conversion circuit Chopping cycle.

Specifically, the rectification unit is first diode, and the anode of the first diode is as the rectification unit First end, second end of the negative terminal of the first diode as the rectification unit.

Specifically, the cut phase waveforms detection and conversion circuit further include the first zener diode, first pressure stabilizing two The anode of pole pipe is electrically connected with the first end of the first resistor, the negative terminal of first zener diode and the first capacitor First end electrical connection.

Specifically, the cut phase waveforms detection and conversion circuit further include voltage stabilization unit, the voltage stabilization unit Input terminal be electrically connected with the power input of the control circuit, the output end of voltage stabilization unit ground connection；

The voltage stabilization unit is used to stablize the voltage of the input terminal of the control circuit.

Specifically, the voltage conversion circuit includes flyback converter and Power Management Unit, the inverse-excitation type conversion Device includes transformer, and the primary side of the transformer is electrically connected with the output end of first rectification circuit, the transformer Primary side includes primary side, secondary side and side three times；

The Power Management Unit is electrically connected with the primary side of the transformer, and the Power Management Unit is for controlling institute State the turn-on time of transformer primary side；

The input terminal of the cut phase waveforms detection and conversion circuit is electrically connected with the side three times, the cut phase waveforms detection It is used to detect the transformer the first signal that side exports three times with conversion circuit；

The Circuit Fault on Secondary Transformer is electrically connected with second rectification circuit, and the Circuit Fault on Secondary Transformer passes through described second Rectification circuit provides power supply for the DC converting circuit.

Specifically, the phase-cut dimming system further includes Voltage loop detection feed circuit；The Voltage loop detection feedback electricity The input terminal on road is electrically connected with the primary side of the voltage conversion circuit, the output end of the Voltage loop detection feed circuit and institute State Power Management Unit electrical connection；The Voltage loop detection feed circuit is used for the primary side electricity according to the voltage conversion circuit The output signal of the voltage-controlled system Power Management Unit.

Specifically, the phase-cut dimming system further includes electromagnetic interference filtering circuit, the electromagnetic interference filtering circuit Input terminal is electrically connected with the output end of the phase-cut dimmer, the output end of the electromagnetic interference filtering circuit and described first whole The input terminal of current circuit is electrically connected；

The electromagnetic interference for the signal that the electromagnetic interference filtering circuit exports for reducing the phase-cut dimmer.

The utility model includes phase-cut dimmer, the first rectification circuit, voltage conversion electricity by the way that phase-cut dimming system is arranged Road, the second rectification circuit, cut phase waveforms detection and conversion circuit, control circuit and DC converting circuit；Control circuit is used for root Corresponding control signal is exported according to second signal, the frequency for controlling signal is greater than the frequency of second signal, and exports control signal To the control terminal of DC converting circuit；The input terminal of DC converting circuit passes through the secondary of the second rectification circuit and voltage conversion circuit Side electrical connection；DC converting circuit is used to export corresponding electric current according to control signal.Realize the luminance of control LED light Degree, to avoid the control that the first signal of side three times is coupled to the DC converting circuit of secondary side using photoelectrical coupler End, while the peripheral circuit being used cooperatively with photoelectrical coupler is avoided, the occupied space of phase-cut dimming system is reduced, simultaneously Reduce the cost of phase-cut dimming system.

Detailed description of the invention

Fig. 1 is a kind of structural schematic diagram of phase-cut dimming system provided by the embodiment of the utility model；

Fig. 2 is a kind of circuit diagram of phase-cut dimming system provided by the embodiment of the utility model；

Fig. 3 is the circuit diagram of another phase-cut dimming system provided by the embodiment of the utility model；

Fig. 4 is the structural schematic diagram of a kind of cut phase waveforms detection and conversion circuit provided by the embodiment of the utility model；

Fig. 5 be a kind of phase-cut dimmer provided by the embodiment of the utility model output waveform and cut phase waveforms detection and turn Change the input waveform figure of circuit；

Fig. 6 is the part of the input waveform of a kind of cut phase waveforms detection provided by the embodiment of the utility model and conversion circuit Enlarged drawing；

Fig. 7 be a kind of phase-cut dimmer provided by the embodiment of the utility model output waveform and cut phase waveforms detection and turn Change the output waveform figure of circuit；

Fig. 8 be utility model embodiment provide another phase-cut dimmer output waveform and cut phase waveforms detection and turn Change the output waveform figure of circuit.

Specific embodiment

The utility model is described in further detail with reference to the accompanying drawings and examples.It is understood that herein Described specific embodiment is used only for explaining the utility model, rather than the restriction to the utility model.It further needs exist for It is bright, part relevant to the utility model is illustrated only for ease of description, in attached drawing rather than entire infrastructure.

Fig. 1 is a kind of structural schematic diagram of phase-cut dimming system provided by the embodiment of the utility model, and Fig. 2 is that this is practical new A kind of circuit diagram for phase-cut dimming system that type embodiment provides, as depicted in figs. 1 and 2, which includes Phase-cut dimmer 10, the first rectification circuit 20, voltage conversion circuit 30, the second rectification circuit 21, cut phase waveforms detection and conversion Circuit 40, control circuit 50 and DC converting circuit 60.The input terminal input ac power of phase-cut dimmer 10, phase-cut dimmer 10 output end is electrically connected with the input terminal of the first rectification circuit 20；The primary side of voltage conversion circuit 30 including electrical isolation and Primary side, primary side are electrically connected with the output end of the first rectification circuit 20, and voltage conversion circuit 30 is used for the first rectification circuit The direct current signal of 20 outputs is converted to the first signal；The input terminal and voltage conversion circuit of cut phase waveforms detection and conversion circuit 40 30 primary side electrical connection, the input terminal triac electricity of the output end and control circuit 50 of cut phase waveforms detection and conversion circuit 40 Connection；Cut phase waveforms detection and conversion circuit 40 are used to the first signal of primary side being converted to second signal, second signal Chopping frequency of the chopping frequency less than the first signal；The output end of control circuit 50 and the control terminal of DC converting circuit 60 are electrically connected It connects；Control circuit 50 is used to export corresponding control signal according to second signal, and the frequency for controlling signal is greater than second signal Frequency, and output control signals to the control terminal of DC converting circuit 60；The input terminal and voltage of second rectification circuit 21 are converted The primary side of circuit 30 is electrically connected, and the input terminal of DC converting circuit 60 is electrically connected with the output end of the second rectification circuit 21；Directly Conversion circuit 60 is flowed to be used to export corresponding electric current according to control signal.

Illustratively, voltage conversion circuit 30 may include Power Management Unit 32 and transformer T1.Transformer T1 and Two rectification circuits 21 form flyback converter 31.The primary side and primary side of voltage conversion circuit 30 can be transformer T1's Primary side 34 and primary side (including primary side 12, secondary side 78 and side 67 three times).The primary side 34 of transformer T1 and first whole The output end of current circuit 20 is electrically connected, and the primary side of transformer T1 includes primary side 12, secondary side 78 and side 67 three times.Power supply pipe Reason unit 32 is electrically connected with the primary side 12 of transformer T1, and Power Management Unit 32 is for controlling leading for transformer T1 primary side 12 The logical time.The input terminal of cut phase waveforms detection and conversion circuit 40 is electrically connected with side 67 three times, cut phase waveforms detection and conversion electricity Road 40 is used to detect transformer T1 the first signal that side 67 exports three times.The secondary side 78 of transformer T1 and the second rectification circuit 21 Electrical connection, transformer T1 secondary side 78 are that DC converting circuit 60 provides power supply by the second rectification circuit 21.

Specifically, primary side 34 includes switching transistor Q1, and during the work time, 32 control switch of Power Management Unit is brilliant The conducting and shutdown of body pipe Q1.Illustratively, switching transistor Q1 is N-type transistor, and Power Management Unit 32 exports high level When, switching transistor Q1 conducting, when Power Management Unit 32 exports low level, switching transistor Q1 shutdown.Work as switching transistor When Q1 is connected, circuit constitutes circuit where the coil of primary side 34, and the coil both ends of primary side 34 are loaded directly into the first rectified current The direct current signal that road 20 exports, the coil of primary side 34 and the magnetic core of transformer T1 store electric energy.In the process, secondary side 78 The coil of side 67 generates the voltage with the voltage reversal of primary side 34, the diode D in secondary side 78 and three times side 67 three times In reverse blocking state, therefore, the secondary side 78 and output end of side 67 provides voltage and current by capacitor three times.When switch is brilliant When body pipe Q1 is turned off, primary side 34 can not constitute circuit, and the electric current in the coil of primary side 34 is zero, at this time in transformer T1 The magnetic field of magnetic core storage is begun to decline, and the voltage phase Tongfang with primary side 34 is induced in secondary side 78 and three times 67 coil of side To voltage, the secondary side 78 and diode D of side 67 is in forward conduction state three times at this time, the electric energy of magnetic core storage flows into electricity Hold and loads.It follows that the signal that the secondary side 78 of transformer T1 and three times side 67 export is that pulse width modulates (Pulse Width Modulation, PWM) signal, chopping frequency is identical as the conducting of switching transistor Q1 shutdown frequency, therefore transformation The chopping frequency for the first signal that the side three times 67 of device T1 exports is very high.Under normal circumstances, the shutdown conducting of switching transistor Q1 Frequency in several KHz or more, therefore the frequency of the chopping frequency of the first signal that the side three times 67 of transformer T1 exports is also several KHz or more.

Since flyback converter 31 has the function of being dielectrically separated from, so on the peripheral circuit of flyback converter 31 It similarly needs and is dielectrically separated from function.Most common two kinds of control models are Voltage Feedback control and Current Feedback Control.This Two kinds of control models require signal being transmitted to 34 coil side of primary side from the secondary side coil side of transformer T1.Specifically Ground, phase-cut dimming system further include Voltage loop detection feed circuit 90；The input terminal and voltage of Voltage loop detection feed circuit 90 The primary side of conversion circuit 30 is electrically connected, and the output end of Voltage loop detection feed circuit 90 is electrically connected with Power Management Unit 32； Voltage loop detects feed circuit 90 and is used to control the defeated of Power Management Unit 32 according to the secondary-side voltage of voltage conversion circuit 30 Signal out makes the primary side output voltage stabilization of transformer T1 to realize Voltage Feedback control.Illustratively, such as Fig. 2 institute Show, the input terminal of Voltage loop detection feed circuit 90 is electrically connected with the side three times 67 of transformer T1, detects the side three times transformer T1 67 output signal, and it is transmitted to Power Management Unit 32, Power Management Unit 32 is controlled according to the output signal of side 67 three times The primary side 34 of transformer T1 makes the primary side output voltage stabilization of transformer T1 to realize Voltage Feedback control.For reality The primary side 12 of existing Voltage loop detection feed circuit 90 and transformer T1, which is realized, to be dielectrically separated from, generally use photoelectrical coupler or The method for increasing an independent coiling on transformer T1 magnetic core realizes isolation signals transmitting.Side 67 and primary side three times in Fig. 2 Photoelectrical coupler U2 is connected between 12.It should be noted that the input terminal of Voltage loop detection feed circuit 90 both can be with two The output end of secondary side 78 is electrically connected, and can be electrically connected with the output end ELV of side 67 three times.Fig. 3 is the utility model embodiment The circuit diagram of another phase-cut dimming system of offer, as shown in figure 3, Voltage loop detection feed circuit 90 input terminal with The secondary side 78 of transformer T1 is electrically connected, and detects the output signal of transformer T1 secondary side 78, and is transmitted to Power Management Unit 32, Power Management Unit 32 controls the primary side 34 of transformer T1 according to the output signal of secondary side 78, to realize that voltage is anti- Feedback control, makes the primary side output voltage stabilization of transformer T1.Photoelectricity coupling is connected in Fig. 3 between secondary side 78 and primary side 12 Clutch U2.

The input terminal of cut phase waveforms detection and conversion circuit 40 is electrically connected with the output end ELV of side 67 three times, input first Signal, cut phase waveforms detection and conversion circuit 40 convert the chopping frequency of the first signal, and the second signal of output is cut Wave frequency rate allows the chopping frequency of second signal normally to detect second in control circuit 50 less than the chopping frequency of the first signal In signal and received frequency range.Illustratively, control circuit 50 can be microprocessor, microcomputer reads second signal Chopping frequency generally in tens Hz to several hundred Hz, therefore cut phase waveforms detection and conversion circuit 40 are by the copped wave frequency of the first signal Rate carries out conversion reduction, exports second signal of the chopping frequency in 50 read range of control circuit.Second signal is equally PWM Signal, the difference with the first signal are chopping frequency of the chopping frequency less than the first signal.

The input terminal triac of control circuit 50 is electrically connected with the output end of cut phase waveforms detection and conversion circuit 40, is read The second signal that cut phase waveforms detection and conversion circuit 40 export, and improve under the premise of guaranteeing the duty ratio of second signal the The chopping frequency of binary signal, the control signal for forming high chopping frequency are exported to DC converting circuit 60.DC converting circuit 60 It can be DC-to-dc converter, the input terminal of DC converting circuit 60 passes through the two of the second rectification circuit 21 and transformer T1 Secondary side 78 is electrically connected, and provides DC power supply for DC converting circuit 60, the output end PWM of control circuit 50 is DC converting circuit 60 control terminal EN provides control signal, and control DC converting circuit 60 exports the duty ratio of electric current, to control direct current conversion Circuit 60 exports the average value of electric current, is embodied as LED light and provides different electric currents, control LED luminous brightness.

In above process, transformer T1 the first signal that side 67 exports three times passes through cut phase waveforms detection and conversion circuit 40 formation second signals are transmitted to control circuit 50, and control circuit 50 forms control signal according to second signal and controls secondary side 78 DC converting circuit 60 export the size of electric current, the light emission luminance of control LED light is realized, to avoid using photoelectric coupling First signal of side 67 three times is coupled to the control terminal of the DC converting circuit 60 of secondary side 78 by device, while being avoided and photoelectricity The peripheral circuit that coupler is used cooperatively, reduces the occupied space of phase-cut dimming system, while reducing phase-cut dimming system Cost.

The technical solution of the present embodiment, phase-cut dimming system include phase-cut dimmer, the first rectification circuit, voltage conversion electricity Road, the second rectification circuit, cut phase waveforms detection and conversion circuit, control circuit and DC converting circuit；Phase-cut dimmer it is defeated Enter and hold input ac power, the output end of phase-cut dimmer is electrically connected with the input terminal of the first rectification circuit；Voltage conversion circuit Primary side and primary side including electrical isolation, primary side are electrically connected with the output end of the first rectification circuit, voltage conversion circuit Direct current signal for exporting the first rectification circuit is converted to the first signal；The input terminal of cut phase waveforms detection and conversion circuit It is electrically connected with the primary side of voltage conversion circuit, the input terminal of the output end and control circuit of cut phase waveforms detection and conversion circuit Electrical connection；Cut phase waveforms detection and conversion circuit are used to the first signal of primary side being converted to second signal, second signal Chopping frequency of the chopping frequency less than the first signal；The output end of control circuit is electrically connected with the control terminal of DC converting circuit； Control circuit is used to export corresponding control signal according to second signal, and the frequency for controlling signal is greater than the frequency of second signal, And output control signals to the control terminal of DC converting circuit；The input terminal of DC converting circuit passes through the second rectification circuit and pressure The primary side of conversion circuit is electrically connected；DC converting circuit is used to export corresponding electric current according to control signal.Realize control The light emission luminance of LED light, to avoid turning the direct current that the first signal of side three times is coupled to secondary side using photoelectrical coupler The control terminal of circuit is changed, while avoiding the peripheral circuit being used cooperatively with photoelectrical coupler, reduces phase-cut dimming system Occupied space, while reducing the cost of phase-cut dimming system.

It continues to refer to figure 1, Fig. 2 and Fig. 3, the phase-cut dimming system can also include electromagnetic interference filtering circuit 70, electromagnetism The input terminal of interference filtering circuit 70 is electrically connected with the output end of phase-cut dimmer 10, the output end of electromagnetic interference filtering circuit 70 It is electrically connected with the input terminal of the first rectification circuit 20；The letter that electromagnetic interference filtering circuit 70 exports for reducing phase-cut dimmer 10 Number electromagnetic interference.Illustratively, electromagnetic interference circuit is by differential mode inductors L1, common-mode inductor L2, the second capacitor C2 and The composition such as three capacitor C3.

In addition, phase-cut dimming system can also include that power safety unit 80 illustratively can be fuse, insure One end of silk is electrically connected with the output end of phase-cut dimmer 10, and the other end is electrically connected with electromagnetic interference filtering circuit 70, fuse The abnormal protection of entire power supply can be provided.

Fig. 4 is the structural schematic diagram of a kind of cut phase waveforms detection and conversion circuit provided by the embodiment of the utility model, such as Shown in Fig. 4, cut phase waveforms detection and conversion circuit 40 include rectification unit 41 and charge-discharge control unit 42, rectification unit 41 Input terminal ELV1 of the first end as cut phase waveforms detection and conversion circuit 40, the second end and charge and discharge control of rectification unit 41 The first end of unit 42 is electrically connected, and the second end ground connection of charge-discharge control unit 42, the output end of charge-discharge control unit 42 is made For the output end TRIAC PWM of cut phase waveforms detection and conversion circuit 40.

Specifically, rectification unit 41 is first diode D1, the anode of first diode D1 as rectification unit 41 the One end, second end of the negative terminal of first diode D1 as rectification unit 41.

Charge-discharge control unit 42 includes first capacitor C1, first resistor R1 and second resistance R2；The of first capacitor C1 One end is electrically connected with the first end of first resistor R1, and the second end of first capacitor C1 is electrically connected with the second end of second resistance R2, The second end of first resistor R1 is electrically connected with the first end of second resistance R2；The second end of first resistor R1 is as charge and discharge control The output end of unit 42, the second end ground connection of second resistance R2.The charge and discharge time of first capacitor C1 is greater than voltage conversion circuit The chopping cycle of 30 the first signal of primary side.

First diode D1 carries out DC rectifier to the first signal, when the voltage of the first signal is greater than zero, the one or two pole Pipe D1 forward conduction, charges to first capacitor C1；When the voltage of the first signal is less than the conducting pressure of its first diode D1 When drop, first diode D1 cut-off, first capacitor C1 discharges to first resistor R1 and second resistance R2 at this time, output second Signal.The charge and discharge time of first capacitor C1 is by the capacitance of first capacitor C1, the resistance value of first resistor R1 and second resistance R2 It determines.Under normal circumstances, the charge and discharge time of first capacitor C1 is greater than cutting for the first signal of primary side of voltage conversion circuit 30 Wave period, and the charge and discharge time of first capacitor C1 is far longer than the copped wave of the first signal of primary side of voltage conversion circuit 30 Period.Therefore in the discharge process of first capacitor C1, another forward conduction of first diode D1, again to first capacitor C1 It charges, to make the voltage of first capacitor C1 there was only smaller decline, therefore first capacitor C1 is defeated during discharge Second signal out is more stable.Illustratively, Fig. 5 is a kind of output of phase-cut dimmer provided by the embodiment of the utility model The input waveform figure of waveform and cut phase waveforms detection and conversion circuit, Fig. 6 are a kind of cut phases provided by the embodiment of the utility model The partial enlarged view of waveforms detection and the input waveform of conversion circuit.As shown in Figure 5 and Figure 6, waveform 1 is the defeated of phase-cut dimmer Waveform out, waveform 2 are the input waveform figure of cut phase waveforms detection and conversion circuit 40.Cut phase waveforms detection and conversion circuit at this time 40 input waveform chopping frequency is high.Fig. 7 be a kind of phase-cut dimmer provided by the embodiment of the utility model output waveform and The output waveform figure of cut phase waveforms detection and conversion circuit, as shown in Figures 5 to 7, the waveform 2 on the basis of Fig. 5, in Fig. 5 Pass through first capacitor C1, first resistor R1 in the rectification of cut phase waveforms detection and conversion circuit 40 and second resistance R2 control the The charge and discharge time of one capacitor C1 reduces the chopping frequency of the input waveform of cut phase waveforms detection and conversion circuit 40, is formed Waveform 3 in Fig. 7.

With continued reference to Fig. 3 and Fig. 4, cut phase waveforms detection and conversion circuit 40 further include the first zener diode E1, and first The anode of zener diode E1 is electrically connected with the first end of first resistor R1, the negative terminal and first capacitor of the first zener diode E1 The first end of C1 is electrically connected.

Specifically, the negative terminal of the first zener diode E1 is electrically connected with the first end of first capacitor C1, when the first pressure stabilizing two When the voltage of pole pipe E1 negative terminal is less than its threshold voltage, the first zener diode E1 conducting, first capacitor C1 discharges, and exports Second signal.When the voltage of the first zener diode E1 negative terminal is greater than its threshold voltage, the first zener diode E1 cut-off, the One capacitor C1 not can be carried out electric discharge, cannot export second signal.Therefore high voltage can be removed by the first zener diode E1 Clutter optimizes the square-wave waveform of the second signal of cut phase waveforms detection and the output of conversion circuit 40, improves the inspection of cut phase waveform The precision of the second signal exported with conversion circuit 40 is surveyed, so as to improve the essence for controlling signal of the output of control circuit 50 Degree, further increases the output electric current of DC converting circuit 60, improves the light modulation precision of phase-cut dimming system.Illustratively, Fig. 8 is the output waveform and cut phase waveforms detection and conversion circuit for another phase-cut dimmer that utility model embodiment provides Output waveform figure, as shown in figure 8, the output waveform 3 of cut phase waveforms detection and conversion circuit 40 removes height on the basis of Fig. 7 It advanced optimizes after pressure clutter as square-wave waveform, such as the waveform 4 in Fig. 8.

Above-mentioned technical solution, cut phase waveforms detection and conversion circuit further include the first zener diode, the first pressure stabilizing two The anode of pole pipe is electrically connected with the first end of first resistor, and the negative terminal of the first zener diode and the first end of first capacitor are electrically connected It connects.The second signal that optimization cut phase waveforms detection and conversion circuit output may be implemented, improves cut phase waveforms detection and conversion The precision of the second signal of circuit output further increases so as to improve the precision for controlling signal of control circuit output The output electric current of DC converting circuit, improves the light modulation precision of phase-cut dimming system.

With continued reference to Fig. 3 and Fig. 4, cut phase waveforms detection and conversion circuit 40 further include voltage stabilization unit 43, and voltage is steady The first end of order member 43 is electrically connected with the power input 3V3 of control circuit 50, the second end ground connection of voltage stabilization unit 43； Voltage of the voltage stabilization unit 43 for the input terminal triac of stabilization control circuit 50.

Specifically, the power input 3V3 of first end and control circuit 50 is connected to ground by the 5th capacitor C5.Voltage is steady Order member 43 includes the second diode D2 and the 4th capacitor C4, the negative terminal of the second diode D2 as voltage stabilization unit 43 the The anode of one end, the second diode D2 is electrically connected with the first end of the 4th capacitor C4, and the second end of the 4th capacitor C4 is as voltage Stablize the second end of unit 43.The anode of second diode D2 is electrically connected with the output end of charge-discharge control unit 42, for for The anode of second diode D2 provides a forward voltage, and is kept by the 4th capacitor C4.Because of the negative terminal of the second diode D2 Voltage is the supply voltage of control circuit 50, when the output end TRIAC PWM of cut phase waveforms detection and conversion circuit 40 output When voltage is greater than the supply voltage of control circuit 50, the second diode D2 conducting, cut phase waveforms detection and conversion circuit 40 it is defeated The portion of energy that the voltage of outlet TRIAC PWM output is higher by the supply voltage of control circuit 50 passes through the power supply of control circuit 50 Input terminal 3V3 and the 5th capacitor C5 is discharged into ground, until the output end TRIAC PWM of cut phase waveforms detection and conversion circuit 40 defeated Voltage out is less than or equal to the supply voltage of control circuit 50.It is possible thereby to ensure that the input terminal triac of control circuit 50 is defeated The voltage entered is not more than the supply voltage of control circuit 50, the voltage mistake for avoiding the input terminal triac because of control circuit 50 from inputting It causes the pin of control circuit 50 to damage greatly, while can further remove the high voltage clutter in second signal, optimize and cut The second signal that phase waveform detection and conversion circuit 40 export.Illustratively, when control circuit 50 is microprocessor, power supply Voltage can be 3.3V, when the voltage of the output end TRIAC PWM of cut phase waveforms detection and conversion circuit 40 output is greater than 3.3V When, the second diode D2 conducting, the voltage of the output end TRIAC PWM output of cut phase waveforms detection and conversion circuit 40 passes through the Five capacitor C5 electric discharge, until being not more than 3.3V, so as to ensure that the voltage of input terminal triac input of control circuit 50 is little In the supply voltage 3.3V of control circuit 50, controlled caused by the voltage for avoiding the input terminal triac because of control circuit 50 from inputting is excessive The pin of circuit 50 processed damages, while can further remove the high voltage clutter in second signal, optimizes the inspection of cut phase waveform Survey the second signal exported with conversion circuit 40.

Note that above are only the preferred embodiment and institute's application technology principle of the utility model.Those skilled in the art's meeting Understand, the utility model is not limited to specific embodiment described here, is able to carry out for a person skilled in the art various bright Aobvious variation, readjustment and substitution is without departing from the protection scope of the utility model.Therefore, although passing through above embodiments The utility model is described in further detail, but the utility model is not limited only to above embodiments, is not departing from It can also include more other equivalent embodiments in the case that the utility model is conceived, and the scope of the utility model is by appended Scope of the claims determine.

Claims (10)

1. a kind of phase-cut dimming system, which is characterized in that including phase-cut dimmer, the first rectification circuit, voltage conversion circuit, Two rectification circuits, cut phase waveforms detection and conversion circuit, control circuit and DC converting circuit；

The input terminal input ac power of the phase-cut dimmer, the output end of the phase-cut dimmer and first rectified current The input terminal on road is electrically connected；

The voltage conversion circuit includes the primary side and primary side of electrical isolation, the primary side and first rectification circuit Output end electrical connection, the voltage conversion circuit is used to the direct current signal that first rectification circuit exports being converted to first Signal；

The input terminal of the cut phase waveforms detection and conversion circuit is electrically connected with the primary side of the voltage conversion circuit, described to cut The output end of phase waveform detection and conversion circuit is electrically connected with the input terminal of the control circuit；The cut phase waveforms detection and turn Circuit is changed for the first signal of the primary side to be converted to second signal, the chopping frequency of the second signal is less than described The chopping frequency of first signal；

The output end of the control circuit is electrically connected with the control terminal of the DC converting circuit；The control circuit is used for basis The second signal exports corresponding control signal, and the frequency of the control signal is greater than the frequency of the second signal, and defeated The control terminal for controlling signal to the DC converting circuit out；

The input terminal of second rectification circuit is electrically connected with the primary side of the voltage conversion circuit, the DC converting circuit Input terminal be electrically connected with the output end of second rectification circuit；The DC converting circuit is used to be believed according to the control Number, export corresponding electric current.

2. phase-cut dimming system according to claim 1, which is characterized in that the cut phase waveforms detection and conversion circuit packet Rectification unit and charge-discharge control unit are included, the first end of the rectification unit is as the cut phase waveforms detection and conversion circuit Input terminal, the second end of the rectification unit is electrically connected with the first end of the charge-discharge control unit, and the charge and discharge is automatically controlled The second end of unit processed is grounded, and the output end of the charge-discharge control unit is as the cut phase waveforms detection and conversion circuit Output end.

3. phase-cut dimming system according to claim 2, which is characterized in that the charge-discharge control unit includes the first electricity Appearance, first resistor and second resistance；

The first end of the first capacitor is electrically connected with the first end of the first resistor, the second end of the first capacitor and institute The second end electrical connection of second resistance is stated, the second end of the first resistor is electrically connected with the first end of the second resistance；Institute State output end of the second end of first resistor as the charge-discharge control unit, the second end ground connection of the second resistance.

4. phase-cut dimming system according to claim 3, which is characterized in that the charge and discharge time of the first capacitor is greater than The chopping cycle of the first signal of primary side of the voltage conversion circuit.

5. phase-cut dimming system according to claim 2, which is characterized in that the rectification unit is first diode, institute First end of the anode of first diode as the rectification unit is stated, the negative terminal of the first diode is single as the rectification The second end of member.

6. phase-cut dimming system according to claim 3, which is characterized in that the cut phase waveforms detection and conversion circuit are also Including the first zener diode, the anode of first zener diode is electrically connected with the first end of the first resistor, described The negative terminal of first zener diode is electrically connected with the first end of the first capacitor.

7. phase-cut dimming system according to claim 1, which is characterized in that the cut phase waveforms detection and conversion circuit are also Including voltage stabilization unit, the input terminal of the voltage stabilization unit is electrically connected with the power input of the control circuit, institute State the output end ground connection of voltage stabilization unit；

The voltage stabilization unit is used to stablize the voltage of the input terminal of the control circuit.

8. phase-cut dimming system according to claim 1, which is characterized in that the voltage conversion circuit include transformer and Power Management Unit, the primary side of the transformer are electrically connected with the output end of first rectification circuit, the transformer Primary side includes primary side, secondary side and side three times；

The Power Management Unit is electrically connected with the primary side of the transformer, and the Power Management Unit is for controlling the change The turn-on time of depressor primary side；

The input terminal of the cut phase waveforms detection and conversion circuit is electrically connected with the side three times, the cut phase waveforms detection and turn Circuit is changed for detecting the transformer the first signal that side exports three times；

The Circuit Fault on Secondary Transformer is electrically connected with second rectification circuit, and the Circuit Fault on Secondary Transformer is rectified by described second Circuit provides power supply for the DC converting circuit.

9. phase-cut dimming system according to claim 8, which is characterized in that further include Voltage loop detection feed circuit；Institute The input terminal for stating Voltage loop detection feed circuit is electrically connected with the primary side of the voltage conversion circuit, and the Voltage loop detection is anti- The output end of current feed circuit is electrically connected with the Power Management Unit；The Voltage loop detection feed circuit is used for according to the voltage The secondary-side voltage of conversion circuit controls the output signal of the Power Management Unit.

10. phase-cut dimming system according to claim 1, which is characterized in that it further include electromagnetic interference filtering circuit, it is described The input terminal of electromagnetic interference filtering circuit is electrically connected with the output end of the phase-cut dimmer, the electromagnetic interference filtering circuit Output end is electrically connected with the input terminal of first rectification circuit；

The electromagnetic interference for the signal that the electromagnetic interference filtering circuit exports for reducing the phase-cut dimmer.