CN202750306U - Reference adjustability-based LED constant-current dimming circuit - Google Patents
Reference adjustability-based LED constant-current dimming circuit Download PDFInfo
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- CN202750306U CN202750306U CN 201220478369 CN201220478369U CN202750306U CN 202750306 U CN202750306 U CN 202750306U CN 201220478369 CN201220478369 CN 201220478369 CN 201220478369 U CN201220478369 U CN 201220478369U CN 202750306 U CN202750306 U CN 202750306U
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Abstract
The utility model relates to a reference adjustability-based LED constant-current dimming circuit that comprises a transformer secondary winding (1), a recertification and filter circuit (2), an LED load (3), an analog dimming circuit (8), and a potentiometer dimming circuit (10). The transformer secondary winding (1), the recertification and filter circuit (2), and the LED load (3) are successively connected; the analog dimming circuit (8) and the potentiometer dimming circuit (10) are connected with one end of a dimming mode selection switch (11); and the other end of the dimming mode selection switch (11) is connected with a current control circuit (5). The analog dimming circuit and the potentiometer dimming circuit select one signal by the dimming mode selection switch to output the selected signal to the current control circuit (5); and the current control circuit controls a transformer secondary feedback control circuit (7).The output of the transformer secondary feedback control circuit is connected with a high-voltage power supply chip and the duty ratio of the high-voltage power supply chip is changed, so that the alternating current output of the transformer secondary winding (1) is changed and thus the constant-current dimming of the LED is realized. According to the utility model, the circuit has advantages of simple structure and convenient application.
Description
Technical field
The utility model relates to the LED lighting field, and special LED dimming control technique is specifically related to a kind of LED constant-current dimming circuit of partial pressure type adjustable reference.
Background technology
Along with the progress of LED lighting technology and popularizing of LED light fixture, so that engineering construction and household project such as square, the hotel, conference halls etc. use the LED light fixture in a large number.People not only rest on the LED product and replace original incandescent lamp, in the energy-conservation happiness that electricity-saving lamp brings, but the LED light fixture are proposed the higher requirement of meeting the tendency, and one of them is exactly the Based Intelligent Control to the light modulation of LED light fixture.
And at present on the market light regulating technology mainly contains two classes: (1) base and the built-in light modulation port of High-voltage PWM converter power supply chip are realized the control function to the secondary current size.But this light-modulating mode belongs to frontline technology, and cost is high, and technical difficulty is large, uses complicated condition.(2) realize control to the LED curtage based on low voltage DC TO DC power supply chip built-in PWM light modulation port or simulation light modulation port.But this light-modulating mode must be equipped with a whole set of interlock circuit because of employing low voltage DC TO DC power supply chip, and major loop can only adopt constant voltage mode.So that circuit is more complicated, cost is also higher like this, Efficiency Decreasing, and whole power supply overall dimension is bigger than normal.
The utility model content
For overcoming the shortcomings and deficiencies of above-mentioned prior art, the utility model provide a kind of simple in structure, use the easily LED constant-current dimming circuit of partial pressure type adjustable reference.
The technical scheme in the invention for solving the above technical problem is:
A kind of LED constant-current dimming circuit of adjustable reference, comprise the transformer secondary winding that connects successively, current rectifying and wave filtering circuit and LED load, also comprise analog light-adjusting circuit and potentiometer light adjusting circuit, described analog light-adjusting circuit and potentiometer light adjusting circuit all are connected with light-modulating mode selector switch one end, the light-modulating mode selector switch other end connects current control circuit, analog light-adjusting circuit and potentiometer light adjusting circuit select one kind of signal to export to current control circuit by the light-modulating mode selector switch, and then finally realize LED load light modulation by the control of current control circuit to transformer secondary feedback control circuit again.
The LED constant-current dimming circuit of adjustable reference also comprises the voltage control circuit that is connected with transformer secondary feedback control circuit, described voltage control circuit is connected with current rectifying and wave filtering circuit, and voltage control circuit and current control circuit are controlled transformer secondary feedback control circuit jointly.
Described voltage control circuit comprise amplifier U2-2, voltage-reference U3 and be connected on the LED load anodal and publicly between two divider resistance R14, R15, same, the inverting input of described amplifier U2-2 connects respectively two divider resistance R14, R15 tie point and integrated circuit U3 voltage reference end, described amplifier U2-2 output connects capacitor C 5 by diode connection transformer secondary feedback control circuit between amplifier U2-2 inverting input and the output.
Described current control circuit comprises amplifier U2-1, voltage-reference U3 and sampling resistor R5, R6; Light adjusting potentiometer VR and resistance R 6 compose in parallel the lower inclined to one side resistance of equivalence, again with upper inclined to one side resistance R 10 series connections to voltage-reference U3 voltage reference end, the LED load current forms a voltage by sampling resistor R5 and voltage-reference U3 reference voltage terminal voltage compares, after export to amplifier U2-1, this signal forms triangular signal by capacitor C 4 integrations that are connected in amplifier U2-1 output and inverting input, exports to transformer secondary feedback control circuit again.
The utility model has following beneficial effect with respect to prior art:
(1) the LED constant-current dimming circuit of adjustable reference described in the utility model has two kinds of optional light-modulating modes, and is flexible and convenient to use; And described circuit does not need to adopt special High-voltage PWM converter dimming power source chip and low voltage DC-DC power supply chip, and is simple for structure, cost is low;
(2) the LED constant-current dimming circuit of adjustable reference described in the utility model adopts the constant-current dimming pattern, greatly improves the light modulation Efficiency and accuracy.
Description of drawings
Fig. 1 is the functional-block diagram of the LED constant-current dimming circuit of adjustable reference described in the utility model.
Fig. 2 is the embodiment schematic diagram of the LED constant-current dimming circuit of adjustable reference described in the utility model.
Embodiment
For the ease of it will be appreciated by those skilled in the art that below in conjunction with drawings and Examples the utility model is described in further detail.
As shown in Figure 1, a kind of LED constant-current dimming circuit of adjustable reference, comprise the transformer secondary winding 1, current rectifying and wave filtering circuit 2 and the LED load 3 that connect successively, 1 output of transformer secondary winding is after current rectifying and wave filtering circuit 2 rectifications, filtering, become direct current signal, this direct current signal is added in the LED load 3 on the one hand, two the divider resistance ground connection of connecting on the other hand; Also comprise analog light-adjusting circuit 8 and potentiometer light adjusting circuit 10, described analog light-adjusting circuit and potentiometer light adjusting circuit all are connected with light-modulating mode selector switch 11 1 ends, light-modulating mode selector switch 11 other ends connect current control circuit 5, analog light-adjusting circuit and potentiometer light adjusting circuit select one kind of signal to export to current control circuit 5 by the light-modulating mode selector switch, and then again by the control of current control circuit to transformer secondary feedback control circuit 7, the output of transformer secondary feedback control circuit connects the high voltage source chip, thereby the duty ratio that changes the high voltage source chip changes transformer secondary winding 1 exchanges output, realizes the constant-current dimming of LED.
During implementation, the LED constant-current dimming circuit of described adjustable reference also comprises the voltage control circuit 6 that is connected with transformer secondary feedback control circuit 7, described voltage control circuit 6 is connected with current rectifying and wave filtering circuit 2, and voltage control circuit 6 is controlled transformer secondary feedback control circuit 7 jointly with current control circuit 5.Analog light-adjusting circuit also is provided with polarity protection and pressure limited protection circuit, is connected the light-modulating mode selector switch with pressure limited protection circuit by polarity protection.
Such as Fig. 2, be the utility model one specific embodiment circuit theory diagrams.Wherein, current rectifying and wave filtering circuit comprises the inductance L 1 that is connected on transformer secondary winding positive output end and the ground capacity that is connected to inductance L 1 two ends.Transformer secondary feedback control circuit adopts optocoupler U1, the light-emitting diode minus earth of optocoupler U1, and the light-emitting diode positive pole of optocoupler U1 connects voltage control circuit and current control circuit output by current-limiting resistance R12; Optocoupler U1 output connects the high voltage source chip.
Such as Fig. 2, voltage control circuit comprise amplifier U2-2, voltage-reference U3 and be connected on the LED load anodal and publicly between two divider resistance R14, R15, same, the inverting input of described amplifier U2-2 connects respectively wiring point and the integrated circuit U3 output of two divider resistance R14, R15, the amplifier output is connected to feedback circuit, is connected to a capacitor C 5 between amplifier inverting input and the output.The reference voltage that a 2.5VDC is provided by voltage-reference U3 is adjusted in right amount by R13 and is formed a reference voltage and compare with the voltage divider that R14 and R15 form, the LED load voltage is processed by amplifier by R14, R15 dividing potential drop and the reference voltage result after relatively, forms a triangular wave by the C5 integration and delivers to feedback loop and process.
Described potentiometer light modulation loop selects one kind of signal to export to current control circuit with simulation light modulation loop by the light-modulating mode selector switch, and current control circuit comprises amplifier U2-1, voltage-reference U3, sampling resistor R5; Light adjusting potentiometer VR and resistance R 6 compose in parallel the lower inclined to one side resistance of equivalence, again with upper inclined to one side resistance R 10 series connections to voltage-reference U3 voltage reference end, the LED load current forms a voltage by sampling resistor R5 and voltage-reference U3 reference voltage terminal voltage compares, after export to amplifier U2-1, this signal forms triangular signal by capacitor C 4 integrations that are connected in amplifier U2-1 output and inverting input, exports to transformer secondary feedback control circuit 7 again.
As shown in Figure 2, single-pole double throw opens the light K1 when connecting 1 end as the light-modulating mode selector switch, what select is the potentiometer light-modulating mode, potentiometer VR and resistance R 6 compose in parallel the lower inclined to one side resistance of equivalence, again and a upper inclined to one side resistance R 10 be connected between voltage-reference U3 voltage reference end and the transformer secondary output winding ground.Voltage-reference U3 provides the reference voltage of a 2.5VDC by the upper inclined to one side resistance of R10() consist of a voltage divider and form a reference voltage with R6 and upper VR.The LED load current forms a voltage by the R5 sample resistance and reference voltage compares, and the result of formation is processed by amplifier, forms a triangular wave by the C4 integration and delivers to the feedback loop processing.So just can not change and change the LED load current in the situation of sample resistance.The effect of the resistance R 11 of connecting with potentiometer VR is to set the minimum of lower inclined to one side resistance, the minimum ratio of namely light modulation.
Single-pole double throw opens the light K1 when connecting 2 end as the light-modulating mode selector switch, what select is analog dimming mode, resistance R 6, R7 composes in parallel the lower inclined to one side resistance of equivalence, and upper inclined to one side resistance R 10 is connected between voltage-reference U3 voltage reference end and the secondary winding ground, the output of 0-10VDC signal output apparatus is received between the upper and lower inclined to one side resistance, connects simultaneously amplifier U2-1 inverting input.The reference voltage that U3 provides a 2.5VDC is by the upper inclined to one side resistance of R10() R7 in parallel with R6 forms time inclined to one side electric resistance partial pressure and forms a reference voltage, but this reference voltage is subjected to change from the impact of the external 0-10VDC signal of R8.The LED load current forms a voltage by the R5 sample resistance and reference voltage compares, and the result of formation is processed by amplifier, forms a triangular wave by the C4 integration and delivers to the feedback loop processing.
The effect of voltage-stabiliser tube ZD2 is to limit the extraneous signal voltage magnitude, and diode D3 prevents the extraneous signal error-polarity connection, resistance R 9 be ZD2 current-limiting resistance in case ZD2 puncture.
The utility model comprises that also transformer secondary output assists winding; auxiliary winding is set helps on the one hand to solve the load short circuits protection; be convenient on the other hand stablize the IC operating voltage; for other each functional circuit provides operating voltage; because the LED load changes with different light fixtures; so stablize the operating voltage energy of IC so that the applicability of this driver is stronger, the LED load that can arrange in pairs or groups different.
Above-mentioned only is the more excellent execution mode of the utility model; in the situation that does not deviate from the utility model spirit and essence thereof; those of ordinary skill in the art work as can make various corresponding changes and distortion according to the utility model, but these changes and distortion all should belong to the protection range of the appended claim of the utility model.
Claims (8)
1. the LED constant-current dimming circuit of an adjustable reference, comprise the transformer secondary winding (1) that connects successively, current rectifying and wave filtering circuit (2) and LED load (3), it is characterized in that: also comprise analog light-adjusting circuit (8) and potentiometer light adjusting circuit (10), described analog light-adjusting circuit and potentiometer light adjusting circuit all are connected with light-modulating mode selector switch (11) one ends, the light-modulating mode selector switch other end connects current control circuit (5), analog light-adjusting circuit and potentiometer light adjusting circuit select one kind of signal to export to current control circuit by the light-modulating mode selector switch, and then finally realize LED load (3) light modulation by the control of current control circuit to transformer secondary feedback control circuit (7) again.
2. the LED constant-current dimming circuit of adjustable reference according to claim 1, it is characterized in that: also comprise the voltage control circuit (6) that is connected with transformer secondary feedback control circuit (7), described voltage control circuit (6) is connected with current rectifying and wave filtering circuit (2), and voltage control circuit (6) is controlled transformer secondary feedback control circuit (7) jointly with current control circuit (5).
3. the LED constant-current dimming circuit of adjustable reference according to claim 2, it is characterized in that: described voltage control circuit (6) comprise amplifier U2-2, voltage-reference U3 and be connected on the LED load anodal and publicly between two divider resistance R14, R15, same, the inverting input of described amplifier U2-2 connects respectively two divider resistance R14, R15 tie point and integrated circuit U3 voltage reference end, described amplifier U2-2 output connects capacitor C 5 by diode connection transformer secondary feedback control circuit (7) between amplifier U2-2 inverting input and the output.
4. the LED constant-current dimming circuit of adjustable reference according to claim 1, it is characterized in that: described current control circuit (5) comprises amplifier U2-1, voltage-reference U3 and sampling resistor R5, R6; Light adjusting potentiometer VR and resistance R 6 compose in parallel the lower inclined to one side resistance of equivalence, again with upper inclined to one side resistance R 10 series connections to voltage-reference U3 voltage reference end, the LED load current forms a voltage by sampling resistor R5 and voltage-reference U3 reference voltage terminal voltage compares, after export to amplifier U2-1, this signal forms triangular signal by capacitor C 4 integrations that are connected in amplifier U2-1 output and inverting input, exports to transformer secondary feedback control circuit (7) again.
5. the LED constant-current dimming circuit of adjustable reference according to claim 1, it is characterized in that: described current rectifying and wave filtering circuit (2) comprises the inductance L 1 that is connected on transformer secondary winding (1) positive output end and the ground capacity that is connected to inductance L 1 two ends.
6. the LED constant-current dimming circuit of adjustable reference according to claim 1, it is characterized in that: described transformer secondary feedback control circuit (7) comprises optocoupler, the light-emitting diode minus earth of optocoupler, the light-emitting diode positive pole of optocoupler connects voltage control circuit (6) and current control circuit (5) by current-limiting resistance; The optocoupler output connects the high voltage source chip.
7. the LED constant-current dimming circuit of the described adjustable reference of any one according to claim 1-6 is characterized in that: described analog light-adjusting circuit (8) is connected the light-modulating mode selector switch by polarity protection with pressure limited protection circuit.
8. the LED constant-current dimming circuit of the described adjustable reference of any one according to claim 1-6 is characterized in that: also be included as the auxiliary winding of transformer secondary output that each functional circuit provides operating voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220478369 CN202750306U (en) | 2012-09-19 | 2012-09-19 | Reference adjustability-based LED constant-current dimming circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220478369 CN202750306U (en) | 2012-09-19 | 2012-09-19 | Reference adjustability-based LED constant-current dimming circuit |
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| Publication Number | Publication Date |
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| CN202750306U true CN202750306U (en) | 2013-02-20 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220478369 Expired - Fee Related CN202750306U (en) | 2012-09-19 | 2012-09-19 | Reference adjustability-based LED constant-current dimming circuit |
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| CN (1) | CN202750306U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103152939A (en) * | 2013-02-26 | 2013-06-12 | 茂硕电源科技股份有限公司 | Four-in-one light-dimming circuit of light-emitting diode (LED) power source |
| CN110768510A (en) * | 2019-09-30 | 2020-02-07 | 上海芃矽半导体技术有限公司 | Control circuit and method and power converter |
-
2012
- 2012-09-19 CN CN 201220478369 patent/CN202750306U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103152939A (en) * | 2013-02-26 | 2013-06-12 | 茂硕电源科技股份有限公司 | Four-in-one light-dimming circuit of light-emitting diode (LED) power source |
| CN103152939B (en) * | 2013-02-26 | 2016-09-07 | 茂硕电源科技股份有限公司 | A kind of LED power four-in-one light adjusting circuit |
| CN110768510A (en) * | 2019-09-30 | 2020-02-07 | 上海芃矽半导体技术有限公司 | Control circuit and method and power converter |
| CN110768510B (en) * | 2019-09-30 | 2022-09-20 | 上海矽力杰微电子技术有限公司 | Control circuit and method and power converter |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130220 Termination date: 20190919 |
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| CF01 | Termination of patent right due to non-payment of annual fee |