CN204539556U - The switch dimming drive circuit of Width funtion LED and LED dimming control system - Google Patents

Abstract

The utility model discloses a kind of switch dimming drive circuit and LED dimming control system of Width funtion LED.Dimming control system comprises LED and the shared mains switch (S0) of some parallel connections, and each LED includes switch dimming drive circuit, by mains switch (S0) simultaneously to each LED light modulation.Switch dimming drive circuit comprises LED light source circuit (6), rectification circuit (4), constant-current source circuit (7), voltage stabilizing and pfc circuit (5), produce pulse output signals and adjusting pulsewidth duty ratio and the adjusting control circuit (8) of periodically output pulse signal, the sampled voltage end (A) of the voltage output end (B) of the output of adjusting control circuit (8) and voltage stabilizing and pfc circuit (5) is connected, under power switch circuit (11) controls, adjusting control circuit (8) produces the pulse switch signal of different duty, control voltage stabilizing and pfc circuit (5) provide time-shared switch voltage to LED light source circuit (6), power control and light modulation are carried out to LED light source circuit (6).Can be applicable to LED light modulation field.

Description

Wide-voltage LED lamp switch dimming drive circuit and LED lamp dimming control system

technical field

The utility model relates to a switch dimming driving circuit of a wide-voltage LED lamp. In addition, the utility model also relates to an LED lamp dimming control system.

Background technique

At present, the application of LEDs is becoming more and more extensive, and LED lamps for daily indoor and outdoor lighting are also becoming more and more popular. Traditional incandescent lamps and fluorescent lamps can be configured with dimmers for dimming, and the output illuminance of the lights can be adjusted to meet people's needs. There is also a need for dimming LED lights, but due to the particularity of LED lights, traditional dimming circuits often cannot adapt to LED lights. The applicant once applied for the Chinese utility model patent of "LED lamp energy-saving control circuit" on January 22, 2009, and its patent number is ZL200910036887.9, which can realize the energy-saving operation state in a specific period of time through the timer, namely Timing two-stage dimming function can be realized. However, this kind of circuit cannot realize dimming of LEDs at any time, and the number of dimming stages can only be two, and it is impossible to realize dimming with more stages. Therefore, for occasions that require dimming at any time and require high dimming Not applicable. At present, there are also LED lamps that are dimmed by a special dimmer, which needs to be provided with a special dimmer at the power switch, so the cost is relatively high. In addition, there are LED lamps that can be dimmed through wireless remote control, which requires a wireless receiver to be installed on each LED lamp, which is costly, and the dimming of a large number of lamps needs to be operated one by one, which is inconvenient to operate and troublesome to use.

Utility model content

The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a switch dimming drive circuit for a wide-voltage LED lamp with simple structure, few components, wide application range, reliable control, and multi-stage dimming at any time. , the dimming driving circuit is embedded in the LED lamp, and the LED lamp can be dimmed without a dimmer.

In addition, the utility model also provides an LED lamp dimming control system, which can conveniently perform large-scale synchronous dimming on multiple LED lamps without a dimmer, and can centrally control multiple LED lamps. Lamps help save electricity.

The technical solution adopted by the switching and dimming driving circuit of the wide voltage LED lamp of the utility model is: the switching and dimming driving circuit of the wide voltage LED lamp of the utility model includes an LED light source circuit, a rectifying circuit for changing the alternating current of the power supply into direct current, A constant current source circuit for stabilizing the current of the LED light source circuit, the LED light source circuit is connected in series with the constant current source circuit, and the switching and dimming driving circuit of the wide voltage LED lamp also includes voltage stabilization and PFC circuit, a dimming control circuit, the voltage stabilizing and PFC circuit is connected after the rectifier circuit and before the LED light source circuit, the voltage stabilizing and PFC circuit includes a PFC integrated chip, an output switch tube, and the dimming control The circuit is used to generate a pulse output signal and adjust the pulse width duty ratio and periodically output the pulse signal. The dimming control circuit includes a segmented control output power integrated circuit, and the output terminal of the dimming control circuit is connected to the stabilized voltage and the sampling voltage terminal of the voltage output terminal of the PFC circuit, under the control of the switching times of the external power supply switching circuit, the dimming control circuit generates pulse switching signals with different duty ratios, and the output terminal of the dimming control circuit When it is at a high level, the voltage at the sampling voltage terminal is fed back to the PFC integrated chip to make its output zero, and the switch tube is not turned on, so that the output voltage of the voltage output terminal and the voltage input of the LED light source circuit The input voltage of the terminal is lower than the forward conduction voltage of the LED light source circuit, and when the output terminal of the dimming control circuit is at a low level, the voltage of the sampling voltage terminal is fed back to the PFC integrated chip so that the output is a normal voltage , the switching tube is turned on, so that the input voltage of the voltage input terminal of the LED light source circuit is a normal working voltage, and the time-sharing switching voltage is provided to the LED light source circuit through the dimming control circuit in response to the power switch frequency signal, Therefore, power control and dimming are performed on the LED light source circuit, and the power switch circuit is connected to the power input terminal before the rectification circuit.

The segmented control output power integrated circuit includes an RC oscillating circuit, a 256 frequency division circuit, a debounce circuit, a mode control circuit and four pins, the RC oscillating circuit is used to generate an oscillating signal, and the oscillating signal is divided by 256 After the circuit generates a square wave output, after the square wave output passes through the debounce circuit, under the control of the mode control circuit, the signal of the opening and closing times of the power switch is sensed, and a pulse switch signal is output by preset various duty ratios , the first pin is the ground terminal, the third pin is the power input end, the second pin is the trigger signal input end, the fourth pin is the square wave pulse signal output end, and the second pin is connected with the debounce circuit.

The dimming control circuit also includes an N-channel field effect transistor and its drain resistor, as well as a filter capacitor, a bleeder resistor, a diode, an electrolytic capacitor, and a voltage divider resistor. After the bleeder resistor and the filter capacitor are connected in parallel, It is connected and connected with the anode of the diode and the trigger signal input terminal of the segmented control output power integrated circuit, connected with the trigger signal input terminal, and the voltage dividing resistor is connected in parallel with the electrolytic capacitor and then connected with the The cathode of the diode is connected to the voltage input terminal of the segmented control output power integrated circuit, the gate of the N-channel field effect transistor is connected to the current signal output terminal of the segmented control output power integrated circuit, The source of the N-channel field effect transistor is connected to the anode of a sampling Zener diode and the sampling voltage terminal of the voltage stabilization and PFC circuit, and the drain of the N-channel field effect transistor is connected to the drain resistor series Then connect to the power supply input end of the PFC integrated chip.

The voltage stabilizing and PFC circuit is a switching power supply, and the PFC integrated chip adopts a power supply PFC power factor control circuit modeled as MC33262, and its peripheral components include capacitors, resistors, diodes, Zener diodes, and transformers/inductors.

The switching and dimming driving circuit of the wide-voltage LED lamp also includes an overcurrent protection circuit and a power supply lightning protection circuit. The overcurrent protection circuit is connected to the power supply input terminal. The overcurrent protection circuit includes an overcurrent protection fuse. The lightning protection circuit of the power supply is connected before the rectification circuit.

The switching and dimming driving circuit of the wide-voltage LED lamp also includes a power supply EMC circuit and a light source EMC circuit, the power supply EMC circuit is connected before the rectification circuit, and the light source EMC circuit is connected after the voltage stabilization and PFC circuit , Before the LED light source circuit.

The LED light source circuit includes at least one group of several LEDs connected in series.

The constant current source circuit includes at least one N-channel depletion-type field-effect transistor, the drain of the N-channel depletion-type field-effect transistor is a contact, and the source of the N-channel depletion-type field-effect transistor A short circuit with the gate constitutes another contact.

Alternatively, the constant current source circuit includes at least one N-channel JFET, the drain of the N-channel JFET is a contact, and the source of the N-channel JFET is connected to The grid phases are shorted to form another contact.

The switching and dimming driving circuit of the wide-voltage LED lamp also includes a heat dissipation fan circuit, the heat dissipation fan circuit is connected in series with the LED light source circuit and the constant current source circuit, and the heat dissipation fan circuit includes a lamp fan motor, at least A fan shunt resistor and a fan voltage regulator diode connected in parallel with the fan shunt resistor.

The technical scheme adopted by the LED lamp dimming control system of the utility model is: the LED lamp dimming control system of the utility model includes several parallel LED lamps and a shared power switch, each of the LED lamps includes a wide voltage LED lamp The switch dimming drive circuit, through the power switch to dim each of the LED lamps at the same time; the switch dimming drive circuit of the wide voltage LED lamp includes an LED light source circuit, a rectification circuit for changing the alternating current of the power supply into direct current, A constant current source circuit for stabilizing the current of the LED light source circuit, the LED light source circuit is connected in series with the constant current source circuit, and the switching and dimming driving circuit of the wide voltage LED lamp also includes voltage stabilization and PFC circuit, a dimming control circuit, the voltage stabilizing and PFC circuit is connected after the rectifier circuit and before the LED light source circuit, the voltage stabilizing and PFC circuit includes a PFC integrated chip, an output switch tube, and the dimming control The circuit is used to generate a pulse output signal and adjust the pulse width duty ratio and periodically output the pulse signal. The dimming control circuit includes a segmented control output power integrated circuit, and the output terminal of the dimming control circuit is connected to the stabilized voltage and the sampling voltage terminal of the voltage output terminal of the PFC circuit, under the control of the switching times of the external power supply switching circuit, the dimming control circuit generates pulse switching signals with different duty ratios, and the output terminal of the dimming control circuit When it is at a high level, the voltage at the sampling voltage terminal is fed back to the PFC integrated chip to make its output zero, and the switch tube is not turned on, so that the output voltage of the voltage output terminal and the voltage input of the LED light source circuit The input voltage at the terminal is lower than the forward conduction voltage of the LED light source circuit, and when the output terminal of the dimming control circuit is at a low level, the voltage at the sampling voltage terminal is fed back to the PFC integrated chip so that the output is a normal voltage , the switching tube is turned on, so that the input voltage of the voltage input terminal of the LED light source circuit is a normal working voltage, and the time-sharing switching voltage is provided to the LED light source circuit through the dimming control circuit in response to the power switch frequency signal, Therefore, power control and dimming are performed on the LED light source circuit, and the power switch circuit is connected to the power input terminal before the rectification circuit.

The segmented control output power integrated circuit includes an RC oscillating circuit, a 256 frequency division circuit, a debounce circuit, a mode control circuit and four pins, the RC oscillating circuit is used to generate an oscillating signal, and the oscillating signal is divided by 256 After the circuit generates a square wave output, after the square wave output passes through the debounce circuit, under the control of the mode control circuit, the signal of the opening and closing times of the power switch is sensed, and a pulse switch signal is output by preset various duty ratios , the first pin is the ground terminal, the third pin is the power input end, the second pin is the trigger signal input end, the fourth pin is the square wave pulse signal output end, and the second pin is connected with the debounce circuit.

The dimming control circuit also includes an N-channel field effect transistor and its drain resistor, as well as a filter capacitor, a bleeder resistor, a diode, an electrolytic capacitor, and a voltage divider resistor. After the bleeder resistor and the filter capacitor are connected in parallel, It is connected and connected with the anode of the diode and the trigger signal input terminal of the segmented control output power integrated circuit, connected with the trigger signal input terminal, and the voltage dividing resistor is connected in parallel with the electrolytic capacitor and then connected with the The cathode of the diode is connected to the voltage input terminal of the segmented control output power integrated circuit, the gate of the N-channel field effect transistor is connected to the current signal output terminal of the segmented control output power integrated circuit, The source of the N-channel field effect transistor is connected to the anode of a sampling Zener diode and the sampling voltage terminal of the voltage stabilization and PFC circuit, and the drain of the N-channel field effect transistor is connected to the drain resistor series Then connect to the power supply input end of the PFC integrated chip.

The voltage stabilizing and PFC circuit is a switching power supply, and the PFC integrated chip adopts a power supply PFC power factor control circuit modeled as MC33262, and its peripheral components include capacitors, resistors, diodes, Zener diodes, and transformers/inductors.

The switching and dimming driving circuit of the wide-voltage LED lamp also includes an overcurrent protection circuit and a power supply lightning protection circuit. The overcurrent protection circuit is connected to the power supply input terminal. The overcurrent protection circuit includes an overcurrent protection fuse. The lightning protection circuit of the power supply is connected before the rectification circuit.

The switching and dimming driving circuit of the wide-voltage LED lamp also includes a power supply EMC circuit and a light source EMC circuit, the power supply EMC circuit is connected before the rectification circuit, and the light source EMC circuit is connected after the voltage stabilization and PFC circuit , Before the LED light source circuit.

The LED light source circuit includes at least one group of several LEDs connected in series.

The constant current source circuit includes at least one N-channel depletion-type field-effect transistor, the drain of the N-channel depletion-type field-effect transistor is a contact, and the source of the N-channel depletion-type field-effect transistor A short circuit with the gate constitutes another contact.

Alternatively, the constant current source circuit includes at least one N-channel JFET, the drain of the N-channel JFET is a contact, and the source of the N-channel JFET is connected to The grid phases are shorted to form another contact.

The switching and dimming driving circuit of the wide-voltage LED lamp also includes a heat dissipation fan circuit, the heat dissipation fan circuit is connected in series with the LED light source circuit and the constant current source circuit, and the heat dissipation fan circuit includes a lamp fan motor, at least A fan shunt resistor and a fan voltage regulator diode connected in parallel with the fan shunt resistor.

The beneficial effects of the utility model are: because the switching and dimming driving circuit of the wide-voltage LED lamp of the utility model includes an LED light source circuit, a rectification circuit for changing the AC power of the power supply into a DC power, and for stabilizing the current of the LED light source circuit The constant current source circuit, voltage stabilization and PFC circuit, dimming control circuit, the LED light source circuit is connected in series with the constant current source circuit, the voltage stabilization and PFC circuit is connected after the rectifier circuit, the LED Before the light source circuit, the voltage stabilizing and PFC circuit includes a PFC integrated chip and an output switch tube. The dimming control circuit is used to generate pulse output signals and adjust the pulse width duty cycle and periodically output pulse signals. The dimming The control circuit includes a segmented control output power integrated circuit, the output terminal of the dimming control circuit is connected to the sampling voltage terminal of the voltage output terminal of the voltage stabilization and PFC circuit, and under the control of the switching times of the external power supply switching circuit, the The dimming control circuit generates pulse switching signals with different duty ratios. When the output terminal of the dimming control circuit is at a high level, the voltage at the sampling voltage terminal is fed back to the PFC integrated chip so that the output is zero. The switch tube is not turned on, so that the output voltage of the voltage output terminal and the input voltage of the voltage input terminal of the LED light source circuit are lower than the forward conduction voltage of the LED light source circuit, and the output terminal of the dimming control circuit When it is at a low level, the voltage at the sampling voltage terminal is fed back to the PFC integrated chip to make its output a normal voltage, and the switch tube is turned on, so that the input voltage of the voltage input terminal of the LED light source circuit is a normal working voltage, The dimming control circuit responds to the power switch times signal, and provides a time-sharing switching voltage to the LED light source circuit, thereby performing power control and dimming on the LED light source circuit, and the power switch circuit is connected to the rectifier circuit The previous power input terminal; the utility model embeds the dimming drive circuit in the LED lamp, and uses the time-sharing switch principle to adjust the pulse width of the output pulse signal under the control of the dimming control circuit, that is, to adjust the duty cycle ratio, so that the dimming control circuit provides a time-division switch current to the voltage regulator and PFC circuit, that is, periodically provides a switch current, so that the voltage regulator and PFC circuit periodically output a normal voltage, so that the LED The light source circuit obtains power supply periodically, thereby adjusting the power of the LED lamp, and then obtaining the adjustment change of the light output, that is, the utility model controls the opening of the voltage regulator and the PFC circuit by adjusting the pulse width and duty ratio of the DC pulse signal On and off to control the power supply and dimming of LED lights, so the utility model has simple structure, few components, wide application range, reliable control, multi-stage dimming at any time, good dimming effect, and is suitable for wide voltage applications. The LED lamp can be dimmed in any occasion with a switch without a dimmer, and it is convenient to use.

Since the LED lamp dimming control system of the present invention includes several parallel LED lamps and a common power switch, each of the LED lamps includes a wide-voltage LED lamp switch dimming drive circuit, and the power switch simultaneously controls each The LED lamps are dimmed. Therefore, the LED lamp dimming control system of the present utility model can conveniently perform large-scale synchronous dimming on multiple LED lamps without a dimmer, and can centrally control multiple lamps. It is beneficial to save electric energy, especially suitable for dimming operation of LED lamps in large places.

Description of drawings

Fig. 1 is a schematic diagram of the switch dimming drive circuit of the wide-voltage LED lamp in the first and third embodiments of the utility model;

Fig. 2 is a schematic diagram of the switch dimming driving circuit of the wide-voltage LED lamp in the second and fourth embodiments of the utility model;

3 is a schematic diagram of the internal circuit of the segmented control output power integrated circuit of the embodiment of the present invention;

Fig. 4 is a schematic diagram of the pulse signal output of the segmented control output power integrated circuit of the embodiment of the present invention;

Fig. 5 is the schematic diagram of each functional pin of the PFC integrated chip of the utility model embodiment;

Fig. 6 is the internal circuit principle block diagram of the PFC integrated chip of the utility model embodiment;

Fig. 7 is a schematic diagram of the overall connection of the LED lamp dimming control system in Embodiments 3 and 4 of the present invention.

Detailed ways

Embodiment one:

As shown in Figure 1, Figure 3 to Figure 6, this embodiment is a switch dimming drive circuit for wide-voltage LED lamps, embedded in LED lamps, including an overcurrent protection circuit 1, a power supply lightning protection circuit 2, a power supply EMC circuit 3, LED light source circuit 6, rectifier circuit 4 for changing the alternating current of the power supply to direct current, constant current source circuit 7 for stabilizing the LED light source circuit 6, voltage stabilization and PFC circuit 5, dimming Control circuit 8, light source EMC circuit 10, the overcurrent protection circuit 1 is connected to the power supply input end for overcurrent and short circuit protection, the overcurrent protection circuit 1 includes an overcurrent protection fuse F0, and the power supply lightning protection The circuit 2 is connected before the rectifier circuit 4 and is used for lightning protection, including piezoresistors RV1, RV2, R1, negative temperature coefficient thermistor NTC, discharge tube DSA1, filter capacitor C1, and the power supply EMC circuit 3 is connected after the power supply lightning protection circuit 2 and before the rectification circuit 4, so that the circuit meets the electromagnetic compatibility requirements, including resistor R2, capacitors C2~C4, C14, common mode inductors T1, T4, differential mode inductors L4, L5, the rectification circuit 2 adopts bridge rectification, that is, the rectification bridge D1, and of course other rectification methods can also be used for rectification. The light source EMC circuit 10 is connected after the voltage stabilizing and PFC circuit 5, and the LED light source circuit Before 6, the light source EMC circuit 10 includes a common mode inductor T3, a differential mode inductor L1, L2, the LED light source circuit 6 is connected in series with the constant current source circuit 7, and the voltage stabilization and PFC circuit 5 is a power factor A correction circuit, connected after the rectifier circuit 4 and before the LED light source circuit 6, is used to provide a stable DC power for the LED light source load 6, and improve the power factor of the entire circuit. The voltage stabilization and PFC circuit 5 is a switching power supply. The voltage stabilization and PFC circuit 5 includes a PFC integrated chip U1 and an output switch tube Q1. The PFC integrated chip U1 adopts a power supply PFC power factor control circuit of the model MC33262, and its peripheral components include capacitors C5-C11 , resistors R3-R9, R17, R18, RT, diodes D2, D3, Zener diode DZ, transformer/inductor T2, the LED light source circuit 6 includes several groups of LEDs, each group of LEDs is connected in parallel, and each group includes A plurality of LEDs connected in series, each group of LEDs connected in series can constitute an independent light source or lamp, so centralized control of multiple light sources or lamps can be realized. The constant current source circuit 7 includes several groups of N-channel depletion-type Field effect transistors, each group includes an N-channel depletion type insulated gate field effect transistor (MOS-FET) Q2, ..., Q5, each of the depletion type insulated gate field effect transistors Q2, ..., The drain of Q5 is a contact, and the source and gate of each of the depletion-type field-insulated gate field-effect transistors Q2, ..., Q5 are short-circuited to form another contact, and each of the depletion-type field-insulation A Zener diode D is connected in parallel between the source and the drain of the gate field effect transistors Q2, ..., Q5 5, ..., D8, each group of depletion type insulated gate field effect transistors Q2, ..., Q5 is connected in series with a group of LEDs in the LED light source circuit 6, so that each group of LEDs can obtain Stable working current, avoid over-current burning, and prolong service life; the dimming control circuit 8 is used to generate pulse output signals and adjust the pulse width duty cycle and periodically output pulse signals, and the dimming control circuit 8 includes Segment control output power integrated circuit U2, N-channel field effect transistor Q6 and its drain resistor R11, and filter capacitor C13, discharge resistor R20, diode D9, electrolytic capacitor C12, voltage dividing resistor R19, the segment control output power The integrated circuit U2 includes an RC oscillating circuit, a 256 frequency division circuit, a debounce circuit, a mode control circuit and four pins, the RC oscillating circuit is used to generate an oscillating signal, and the oscillating signal generates a square wave after passing through the 256 frequency dividing circuit Output, after the square wave output passes through the debounce circuit, under the control of the mode control circuit, it senses the signal of the opening and closing times of the power switch, and outputs the pulse switch signal by preset various duty ratios. The first pin is The ground terminal GROUND, the third pin is the power input end VDD, the second pin is the trigger signal input end CP, the fourth pin is the square wave pulse signal output end Q, the second pin is connected with the debounce circuit, the leakage After the discharge resistor R20 and the filter capacitor C13 are connected in parallel, they are connected and connected to the anode of the diode D9 and the trigger signal input terminal CP of the segmented control output power integrated circuit U2, and connected to the trigger signal input terminal CP. connected, the voltage dividing resistor R19 is connected in parallel with the electrolytic capacitor C12 and then connected with the cathode of the diode D9 and the voltage input terminal VDD of the segmented control output power integrated circuit U2, the N-channel field effect The gate of the transistor Q6 is connected to the current signal output terminal Q of the segmented control output power integrated circuit U2, the source of the N-channel field effect transistor Q6 is connected to the anode of a sampling Zener diode D10 and the voltage regulator and the sampling voltage terminal A of the PFC circuit 5, the drain of the N-channel field effect transistor Q6 is connected in series with the drain resistor R11 and then connected to the power supply input terminal VCC of the PFC integrated chip U1, that is The output terminal of the dimming control circuit 8 is connected to the sampling voltage terminal A of the voltage output terminal B of the voltage stabilizing and PFC circuit 5. Under the control of the switching times of the external power supply switching circuit 11, the dimming control circuit 8 generates pulse switching signals with different duty ratios. When the output terminal of the dimming control circuit 8 is at a high level, the voltage at the sampling voltage terminal A is fed back to the PFC integrated chip U1 to make its output zero, The switch tube Q1 is not conducting, the output voltage of the voltage output terminal B is 1.4Uac (Uac is the input voltage value of the AC power supply), and the input voltage of the voltage input terminal C of the LED light source circuit 6 is also 1.4Uac, Make it lower than the forward conduction voltage Vf value of the LED light source circuit 6, the LED light source circuit 6 cannot emit light and does not work , when the output terminal of the dimming control circuit 8 is at a low level, the voltage of the sampling voltage terminal A is fed back to the PFC integrated chip U1 to make its output a normal voltage, and the switch tube Q1 is turned on, so that the The input voltage of the voltage input terminal C of the LED light source circuit 6 is a normal working voltage, and the time-sharing switching voltage is provided to the LED light source circuit 6 through the dimming control circuit 8 in response to the power switch times signal, so that the The LED light source circuit 6 performs power control and dimming, and the power switch circuit 11 is connected to the power input end before the rectifier circuit 4 for switching and dimming the LED lamp.

In this embodiment, the specific principles of the PFC integrated chip U1 are as follows:

(1) In the state without the dimming circuit, the output voltage of the voltage output terminal B of the voltage stabilizing and PFC circuit 5 is kept stable through the following control process: in the circuit of the PFC integrated chip U1, if the voltage output terminal The voltage of B rises, and then the sampling voltage terminal A, that is, the voltage of pin 1, also rises thereupon. Compared with the Vref=2.5V set by the PFC integrated chip U1, the error amplifier output voltage will drop, so that the base of the multiplier output The current value decreases, so that the conduction time of the output switch Q1 is shortened, and the current flowing through the inductor T2 decreases, so that the voltage of the voltage output terminal B decreases; otherwise, the output voltage increases to achieve the purpose of stabilizing the output voltage At the same time, the voltage of the sampling voltage terminal A, that is, pin 1, is finally stabilized at the same as the reference voltage, that is, 2.5V; therefore, the circuit of the PFC integrated chip U1 can stabilize the total output voltage when the voltage of the sampling voltage terminal A changes, and The DC voltage of the voltage input terminal C of the LED light source circuit 6 is equal to the DC voltage of the voltage output terminal B of the voltage stabilizing and PFC circuit 5, and cooperates with the period of the constant current source to maintain the constant voltage and constant current of the LED. working status. In addition, the smaller the sampling voltage terminal A of the PFC integrated chip U1 is, the longer the conduction time of the output switching tube Q1 is, and the output voltage is increased. When the sampling voltage terminal A of the PFC integrated chip U1 is larger, the The shorter the conduction time of the output switch tube Q1 is, the lower the output voltage is, the PFC integrated chip U1 does not work, and the output voltage is zero.

(2) In the state where the dimming circuit of the present invention is provided, when the output terminal of the dimming control circuit 8 is at a high level, that is, the N-channel field effect transistor Q6 is turned on, and the sampling voltage of the sampling voltage terminal A is The voltage is stabilized by the sampling Zener diode D10 and is set to 5V. At this time, the voltage of the sampling voltage terminal A is fed back to the PFC integrated chip U1, so that it does not work when it reaches the threshold, and the output voltage is 1.4Uac (Uac is AC power input voltage value), lower than the forward conduction voltage Vf value of the LED light source circuit 6, at this time, the VCC pin of the PFC integrated chip U is powered by the startup resistor R5 and is in a dormant state; the dimming When the output terminal of the control circuit 8 is at a low level, that is, the N-channel field effect transistor Q6 is cut off, and at this time, the voltage stabilizing and PFC circuit 5 is equivalent to the working state without the dimming control circuit 8, that is, normal Regulating the voltage makes the LED emit light according to the rated state, without affecting the normal circuit operation.

(3) In this embodiment, five kinds of duty cycle output pulse switch signals are preset in the segmental control output power integrated circuit U1, that is, each time the power switch is turned on and off, the square wave pulse signal output terminal Q will output five cycles in turn. PWM duty ratio signals, the duty ratios of the five PWM duty ratio signals are 0%, 20%, 40%, 60%, 80%; The second pin of the segmental control output power integrated circuit U1 is the trigger signal input terminal CP to sense the rising string signal, and the fourth pin is the square wave pulse signal output terminal Q with a high level output duty cycle of 0%. When it is turned on for the second time When the switching element S1 is turned on, the output duty ratio is 20%, when the switching element S1 is turned on for the third time, the output duty ratio is 40%, when the switching element S1 is turned on for the fourth time, the output is The duty cycle is 60%, when the switch element S1 is turned on for the fifth time to perform the light-on operation, the output duty cycle is 80%, when the switch element S1 is turned on for the sixth time to perform the light-on operation, the output duty cycle is 0%, and the second A cycle, and so on. Correspondingly, when the switch element S1 is turned on for the first time to turn on the light, the duty cycle of the DC voltage at the voltage input end C of the LED light source circuit 6 is the duty cycle of the voltage output end B of the voltage stabilizing and PFC circuit 5 . The duty cycle is 100%. When the switch element S1 is turned on for the second time to turn on the light, the duty cycle of the DC voltage at the voltage input terminal C is 80%. When the switch element S1 is turned on for the third time to turn on the light, the voltage input The duty cycle of the DC voltage at the terminal C is 60%, and when the switch element S1 is turned on for the fourth time to perform the light-on operation, the DC voltage duty cycle of the voltage input terminal C is 40%, and the switch element S1 is turned on for the fifth time to perform the light-on operation , the duty cycle of the DC voltage at the voltage input terminal C is 20%, and when the switch element S1 is turned on for the sixth time to turn on the light, the output duty cycle is 100%, and the second cycle starts, and so on; by adjusting the duty cycle Ratio, the average working current is adjusted, so the brightness and power of the LED lamp can be adjusted, so as to realize the dimming function.

In this embodiment, the dimming drive circuit is embedded in the LED lamp, and the pulse width of the output pulse signal is adjusted under the control of the dimming control circuit 8 by using the time-sharing switch principle, that is, the duty cycle is adjusted, so that the Dimming control circuit 8 provides time-sharing switching current to described voltage stabilizing and PFC circuit 5, promptly provides switching current periodically, makes described stabilizing and PFC circuit 5 periodically output normal voltage, makes described LED light source 6 The circuit obtains power supply periodically, thereby adjusting the power of the LED lamp, and then obtaining the adjustment change of the light output, that is, controlling the opening and closing of the voltage stabilization and the PFC circuit 5 by adjusting the pulse width and duty cycle of the DC pulse signal, To control the power supply and dimming of LED lamps, this embodiment has simple structure, few components, wide power range, reliable control, multi-stage dimming at any time, good dimming effect, and is suitable for wide voltage applications. A dimmer is needed to realize the dimming of the LED lamp in any occasion with a switch, which is convenient to use.

Embodiment two:

As shown in Figure 2, the difference between this embodiment and Embodiment 1 is that in this embodiment, each group of the constant current source circuits 7 includes an N-channel junction field effect transistor (J-FET) Q2, ... , Q5, the drain of each of the N-channel junction field effect transistors Q2, ..., Q5 is a contact, and the source and gate of each of the N-channel junction field-effect transistors Q2, ..., Q5 The poles are short-circuited to form another contact, that is, the present embodiment uses an N-channel junction field-effect transistor to replace the N-channel depletion-type field-effect transistor in Embodiment 1, and the functions and effects realized by the two are the same; in addition, the The switch dimming drive circuit of the wide-voltage LED lamp also includes a cooling fan circuit 9, the cooling fan circuit 9 is connected in series with the LED light source circuit 6 and the constant current source circuit 7, and the cooling fan circuit 9 includes a lamp The fan motor DM, three fan shunt resistors R14, R15, R16 and the fan voltage regulator diode D4 connected in parallel with the fan shunt resistors R14, R15, R16 make the voltage of the lamp fan motor DM controlled within a certain range to avoid The instantaneous voltage is too high caused by the switch surge impact generated by multiple lamps being turned on at the same time, which reduces the impact on the lamp fan motor DM, avoids damage to the fan, and ensures the heat dissipation and stable operation of the entire circuit. The fan shunt resistors R14, R15, R16 is used for shunting of high-power circuits to avoid high temperature caused by a single resistor. Since the LED lamp in this embodiment is equipped with a cooling fan, its heat dissipation effect is better, and it is an active cooling LED lamp, which is more suitable for high-power LED lamps.

The remaining features of this embodiment are the same as those of Embodiment 1.

Embodiment three:

As shown in Figure 7, the present embodiment is a dimming control system for LED lamps, including several parallel LED lamps DS1, DS2, ..., DS(n) and a shared power switch S0, each of the LED lamps DS1, DS2, ..., DS(n) all include the switching and dimming drive circuit of the wide-voltage LED lamp in Embodiment 1, through the power switch S0, each of the LED lamps DS1, DS2, ..., DS (n) Perform dimming control. Therefore, the LED lamp dimming control system of this embodiment can conveniently perform large-scale synchronous dimming of multiple LED lamps without a dimmer, and can centrally control multiple lamps, which is conducive to saving electric energy, and is especially suitable for large places Such as the dimming operation of LED lights in cinemas, gymnasiums, etc.

Embodiment four:

The difference between the present embodiment and the third embodiment is that in this embodiment, each of the LED lamps DS1, DS2, ..., DS(n) includes the switching and dimming driving circuit of the wide-voltage LED lamp in the second embodiment, That is, the switch dimming drive circuit of the wide voltage LED lamp is different.

The rest of the features of this embodiment are the same as those of the third embodiment.

The above embodiments are only for illustration, and are not intended to limit the protection scope of the present utility model. All changes made by applying the principles of the present utility model and equivalent changes should be regarded as included in the protection scope of the present utility model.

The utility model can be widely used in the field of dimming of LED lamps. the

Claims (10)

1. A switch dimming drive circuit of a wide-voltage LED lamp, comprising an LED light source circuit (6), a rectifier circuit (4) for changing the AC power of the power supply into a direct current, and being used to perform the described LED light source circuit (6) A steady current constant current source circuit (7), the LED light source circuit (6) is connected in series with the constant current source circuit (7), characterized in that the switch dimming drive circuit of the wide voltage LED lamp also includes Voltage stabilization and PFC circuit (5), dimming control circuit (8), the voltage stabilization and PFC circuit (5) is connected after the rectification circuit (4) and before the LED light source circuit (6), the The voltage stabilizing and PFC circuit (5) includes a PFC integrated chip (U1) and an output switching tube (Q1), and the dimming control circuit (8) is used to generate a pulse output signal and adjust the pulse width duty ratio and periodically output pulses signal, the dimming control circuit (8) includes a segmented control output power integrated circuit (U2), the output terminal of the dimming control circuit (8) is connected to the voltage output terminal of the voltage stabilizing and PFC circuit (5) (B) is connected to the sampling voltage terminal (A), and under the control of the switching times of the external power switch circuit (11), the dimming control circuit (8) generates pulse switching signals with different duty ratios. When the output terminal of the light control circuit (8) is at a high level, the voltage of the sampling voltage terminal (A) is fed back to the PFC integrated chip (U1) to make its output zero, and the switch tube (Q1) does not conduct so that the output voltage of the voltage output terminal (B) and the input voltage of the voltage input terminal (C) of the LED light source circuit (6) are lower than the forward conduction voltage of the LED light source circuit (6), so When the output terminal of the dimming control circuit (8) is at low level, the voltage of the sampling voltage terminal (A) is fed back to the PFC integrated chip (U1), so that the output is a normal voltage, and the switching tube (Q1 ) is turned on, so that the input voltage of the voltage input terminal (C) of the LED light source circuit (6) is a normal operating voltage, and the light source circuit (8) responds to the power switch times signal to the LED light source circuit (6) Provide a time-division switching voltage to perform power control and dimming on the LED light source circuit (6), and the power switch circuit (11) is connected to the power input terminal before the rectification circuit (4). 2. The switching and dimming driving circuit of wide-voltage LED lamp according to claim 1, characterized in that: the segmented control output power integrated circuit (U2) includes an RC oscillator circuit, a 256 frequency division circuit, a debounce circuit, A mode control circuit and four pins, the RC oscillating circuit is used to generate an oscillating signal, the oscillating signal generates a square wave output after passing through the 256 frequency division circuit, and the square wave output passes through the debounce circuit, and in the mode control Under the control of the circuit, the signal of the opening and closing times of the power switch is sensed, and the pulse switching signal is output through a variety of preset duty ratios. The first pin is the ground terminal (GROUND), the third pin is the power input terminal (VDD), and the second pin is the power input terminal (VDD). The second pin is a trigger signal input terminal (CP), the fourth pin is a square wave pulse signal output terminal (Q), and the second pin is connected with the debounce circuit. 3. The switch dimming drive circuit of wide voltage LED lamp according to claim 2, characterized in that: said dimming control circuit (8) also includes an N-channel field effect transistor (Q6) and its drain resistance (R11 ), and filter capacitor (C13), bleeder resistor (R20), diode (D9), electrolytic capacitor (C12), voltage divider resistor (R19), the bleeder resistor (R20) and the filter capacitor (C13) After being connected in parallel, it is connected and connected to the anode of the diode (D9) and the trigger signal input terminal (CP) of the segmented control output power integrated circuit (U2), and connected to the trigger signal input terminal (CP) , the voltage dividing resistor (R19) is connected in parallel with the electrolytic capacitor (C12) and then connected with the cathode of the diode (D3) and the voltage input terminal (VDD) of the segmented control output power integrated circuit (U2) connected, the gate of the N-channel field effect transistor (Q6) is connected to the current signal output terminal (Q) of the segmented control output power integrated circuit (U2), and the N-channel field effect transistor (Q6) The source is connected with the anode of a sampling voltage stabilizing diode (D10) and the sampling voltage terminal (A) of the voltage stabilizing and PFC circuit (5), and the drain of the N channel field effect transistor (Q6) is connected with the sampling voltage terminal (A) of the PFC circuit (5). The drain resistor (R11) is connected in series and then connected to the power supply input terminal (VCC) of the PFC integrated chip (U1). 4. The switching and dimming driving circuit for wide-voltage LED lamps according to claim 1, characterized in that: the voltage stabilization and PFC circuit (5) is a switching power supply, and the PFC integrated chip (U1) adopts a model of MC33262 The power supply PFC power factor control circuit, its peripheral components include capacitors (C5~C11), resistors (R3~R9, R17, R18, RT), diodes (D2, D3), Zener diodes (DZ), transformers/inductors ( T2). 5. The switch dimming drive circuit for wide voltage LED lamps according to claim 1, characterized in that: the switch dimming drive circuit for wide voltage LED lamps also includes an overcurrent protection circuit (1), a power supply lightning protection circuit (2), the overcurrent protection circuit (1) is connected to the power input terminal, the overcurrent protection circuit (1) includes an overcurrent protection fuse (F0), and the power supply lightning protection circuit (2) is connected to the before the rectification circuit (4). 6. The switch dimming drive circuit of wide voltage LED lamp according to claim 1, characterized in that: the switch dimming drive circuit of said wide voltage LED lamp further comprises a power supply EMC circuit (3), a light source EMC circuit (10 ), the power supply EMC circuit (3) is connected before the rectifier circuit (4), the light source EMC circuit (10) is connected after the voltage stabilizing and PFC circuit (5), and the LED light source circuit (6 )Before. 7. The switching and dimming driving circuit for wide-voltage LED lamps according to claim 1, characterized in that: the LED light source circuit (6) includes at least one group of several LEDs connected in series. 8. The switching and dimming driving circuit of wide-voltage LED lamp according to claim 1, characterized in that: the constant current source circuit (7) includes at least one N-channel depletion type field effect transistor, and the N-channel The drain of the channel depletion field effect transistor is a contact, and the source and gate of the N channel depletion field effect transistor are short-circuited to form another contact; or, the constant current source circuit (7) includes At least one N-channel junction field effect transistor, the drain of the N-channel junction field-effect transistor is a contact, and the source and gate of the N-channel junction field-effect transistor are short-circuited to form another contact . 9. The switch and dimming driving circuit for wide-voltage LED lamps according to any one of claims 1 to 8, characterized in that: the switching and dimming driving circuit for wide-voltage LED lamps further includes a cooling fan circuit (9), The heat dissipation fan circuit (9) is connected in series with the LED light source circuit (6) and the constant current source circuit (7), and the heat dissipation fan circuit (9) includes a lamp fan motor (DM), at least one fan shunt Resistors (R14, R15, R16) and fan regulator diodes (D4) connected in parallel with the fan shunt resistors (R14, R15, R16). 10. A dimming control system for LED lamps, characterized in that: it includes several parallel LED lamps (DS1, DS2, ..., DSn) and a shared power switch (S0), each of the LED lamps (DS1, DSn) DS2, ..., DSn) all include the switch dimming drive circuit of the wide-voltage LED lamp described in any one of claims 1 to 9, through the power switch (S0) at the same time each of the LED lamps (DS1, DS2 , ..., DSn) for dimming.