WO2014094648A1

WO2014094648A1 - Split led lamp and driving power supply insertion and extraction protection circuit thereof

Info

Publication number: WO2014094648A1
Application number: PCT/CN2013/090075
Authority: WO
Inventors: 王国求; 吴云波
Original assignee: 深圳桑达百利电器有限公司
Priority date: 2012-12-21
Filing date: 2013-12-20
Publication date: 2014-06-26
Also published as: CN103037585A; CN103037585B

Abstract

The present invention is suitable for the field of light-emitting diode (LED) driving, and provided are a split LED lamp and a driving power supply insertion and extraction protection circuit thereof. In the present invention, when a driving power supply is not connected to an LED lamp board but is connected to an alternating current power supply, a voltage division module performs voltage reduction processing on the output voltage of a rectifier and filter circuit, and after the driving power supply is connected to the LED lamp board, a voltage detection module detects the voltage of a first end of a resistor R4 and correspondingly outputs a control level, so as to drive a voltage division control module to adjust the voltage of the voltage division direct current output by the voltage division module, so that the output level of a voltage comparison circuit is correspondingly adjusted, and then the feedback current of the driving power supply is controlled. Thus, a pulse width modulation (PWM) control circuit of the driving power supply performs constant current driving on the LED lamp board according to the feedback current, thereby guaranteeing that the service life of an LED will not be shortened due to overcurrent when the driving power supply is connected to the LED lamp board.

Description

Split type LED lamp and driving power plugging protection circuit thereof

Technical field

The invention belongs to the field of LED driving, and particularly relates to a split type LED lamp and a driving power plugging protection circuit thereof.

Background technique

At present, LED lamps as a new type of lighting products, its technology is not yet fully mature, and the country has not yet specified a unified standard for LED lamps, the existing LED lamps drive the power supply and the structure of the LED panel is mainly integrated Both style and split type. Since the integrated LED lamp's driving power supply and LED light board are integrated together, the heat dissipation effect will be worse than that of the split type LED lamp. Therefore, the standardized split type LED lamp is the development trend of the future LED lamp.

Since the LED is made of a semiconductor material, it needs to obtain a constant current supply to ensure normal operation. The existing split type LED lamps require that the LED lamp board and the driving power source are connected before the AC power can be connected, because if the LED light board is not connected to the driving power source and then the AC power is first supplied, the The driving power supply is in the constant voltage output mode, and in the constant voltage output mode, the direct current is output in the form of the maximum voltage, which causes the LED's conduction current to be greater than its maximum peak current, thereby causing damage to the LED and affecting the service life of the LED. In the daily operation of the user, if the operation mode is adopted after the power supply is first connected, the LED will be over-current and shorten the service life of the LED, and in serious cases, the LED light board will be directly damaged. Therefore, in the existing split type LED lamp, there is a problem in that the LED overcurrent caused by the AC power supply is not connected in advance due to the completion of the connection of the driving power source and the LED lamp board, and the service life of the LED is shortened.

technical problem

The object of the present invention is to provide a driving power plugging and protecting circuit for a split type LED lamp, which aims to solve the problem that the existing split type LED lamp has early access due to failure to complete the connection between the driving power source and the LED lamp board. The problem of LED overcurrent caused by AC power supply and shortening the service life of the LED.

Technical solution

The invention is realized in this way, a driving power plugging and unplugging protection circuit of a split type LED lamp, a rectifying and filtering circuit of a driving power source, a voltage dividing resistor R1, a voltage dividing resistor R2, a voltage dividing resistor R3, a resistor R4 and a voltage comparison circuit. Connected, the voltage dividing resistor R1 is connected between the output end of the rectifying and filtering circuit and the first end of the voltage dividing resistor R2, and the voltage dividing resistor R2 and the voltage dividing resistor R3 are connected to each other. a first end of the resistor R4, the second end of the resistor R4 is connected to a non-inverting input terminal of the current comparison circuit, and an output level of the voltage comparison circuit and an output level of the current comparison circuit are common to the driving power source The feedback current outputted by the feedback circuit is controlled such that the PWM control circuit of the driving power supply adjusts the output voltage of the transformer T1 of the driving power source according to the feedback current; the driving power plugging protection circuit includes:

a voltage dividing module, wherein the input end and the output end are respectively connected to an output end of the rectifying and filtering circuit and an inverting input end of the voltage comparing circuit, and configured to perform a voltage dividing process on the DC power output by the rectifying and filtering circuit to reduce the The voltage of the direct current, and output a partial voltage direct current;

a voltage detecting module, the input end is connected to the first end of the resistor R4, for detecting the voltage of the first end of the resistor R4, and correspondingly outputting a control level signal according to the detection result;

a voltage dividing control module, a control end and a voltage dividing adjusting end respectively connected to an output end of the voltage detecting module and an output end of the voltage dividing module, configured to adjust a voltage of the voltage dividing direct current according to the control level signal The output level of the voltage comparison circuit is adjusted accordingly.

Another object of the present invention is to provide a split type LED lamp including an LED lamp board, a driving power source, and the above-mentioned driving power plugging protection circuit.

Beneficial effect

The invention adopts a driving power plug-in protection circuit including a voltage dividing module, a voltage detecting module and a voltage dividing control module in a driving power source of the split type LED lamp, wherein the driving power source is not connected to the LED light board but has been connected to the alternating current When the power is supplied, the output voltage of the rectifying and filtering circuit is stepped down by the voltage dividing module, and after the driving power source is connected with the LED lamp board, the first end of the resistor R4 is passed through the voltage detecting module. After the voltage is detected, the control level is outputted to drive the voltage dividing control module to adjust the voltage of the divided DC power output by the voltage dividing module to adjust the output level of the voltage comparison circuit accordingly, thereby achieving control The feedback current of the driving power source is such that the PWM control circuit of the driving power source drives the LED light board to be constant-currently driven according to the feedback current, thereby ensuring that the LED is not over-current when the driving power source is connected to the LED light board. Shorten the service life and solve the problem that the existing split type LED luminaires are connected to the communication in advance due to the failure to complete the connection between the driving power source and the LED light board. LED power caused by overcurrent and shorten the life of the issue of the LED.

DRAWINGS

1 is a block diagram showing a module structure of a split type LED lamp including an LED lamp board, a driving power source, and a driving power plugging protection circuit according to an embodiment of the present invention;

2 is a schematic circuit structural diagram of a driving power plugging and unplugging protection circuit in a split type LED lamp according to an embodiment of the present invention.

Embodiments of the invention

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the embodiment of the invention, the driving power supply plug-in protection circuit including the voltage dividing module, the voltage detecting module and the voltage dividing control module is used in the driving power supply of the split type LED lamp, and the driving power source is not connected to the LED light board but has been connected to the alternating current. When the power is supplied, the output voltage of the rectifying and filtering circuit is stepped down by the voltage dividing module, and after the driving power source and the LED lamp board are connected, the voltage of the first end of the resistor R4 is detected by the voltage detecting module, and then the output is controlled accordingly. The level driving voltage dividing control module adjusts the voltage of the divided voltage DC output by the voltage dividing module to adjust the output level of the voltage comparison circuit accordingly, thereby achieving the feedback current of the driving power source to enable the PWM control circuit of the driving power source according to The feedback current is driven by the constant current of the LED light board, so that the connection between the driving power source and the LED light board is not ensured, and the LED does not shorten the service life due to overcurrent.

FIG. 1 is a block diagram showing a module structure of a split type LED lamp including an LED lamp board, a driving power source, and a driving power plugging protection circuit according to an embodiment of the present invention. For the convenience of description, only parts related to the present invention are shown. Said as follows:

The split type LED lamp provided by the embodiment of the invention comprises an LED lamp board, a driving power source 100 and a driving power plugging protection circuit 200, wherein the LED board and the driving power source 100 are manually connected by a user.

As shown in FIG. 1, the driving power supply 100 includes an EMI filter circuit 101, a rectifier circuit 102, a resistor R5, a PWM control circuit 103, a switch transistor 104, an absorbing circuit 105, a feedback circuit 106, a diode D1, a resistor R6, a transformer T1, and a rectification filter. Circuit 107, current detecting resistor R7, optocoupler U1, diode D2, diode D3, resistor R8, resistor R9, resistor R10, capacitor C1, voltage dividing resistor R1, voltage dividing resistor R2, voltage dividing resistor R3, resistor R4, current comparison The circuit 108, the reference source TL, and the voltage comparison circuit 109. The voltage dividing resistor R1 is connected between the output end of the rectifying and filtering circuit 107 and the first end of the voltage dividing resistor R2, and the voltage dividing resistor R2 and the voltage dividing resistor R3 are connected to the first end of the resistor R4, and the resistor R4 The second end is connected to the non-inverting input terminal of the current comparison circuit 108. The output level of the voltage comparison circuit 109 and the output level of the current comparison circuit 108 jointly control the feedback current output by the feedback circuit 106, so that the PWM control circuit 103 The feedback current adjusts the output voltage of the transformer T1; the output end of the rectifying and filtering circuit 107 and the first end of the current detecting resistor R7 are respectively used for connecting the LED+ and the output LED- of the LED lamp board, and the LED of the optocoupler U1 The anode and the first end of the resistor R10 are respectively connected to the output end of the rectifying and filtering circuit 107 and the first end of the current detecting resistor R7.

The driving power plugging protection circuit 200 is connected to the rectifying and filtering circuit 107 of the driving power source 100, the voltage dividing resistor R1, the voltage dividing resistor R2, the voltage dividing resistor R3, the resistor R4, and the voltage comparing circuit 109; and the driving power plugging protection circuit 200 include:

The voltage dividing module 201, the input end and the output end are respectively connected to the output end of the rectifying and filtering circuit 107 and the inverting input end of the voltage comparing circuit 109, for dividing the direct current outputted by the rectifying and filtering circuit 107 to reduce the direct current Voltage and output a voltage divider DC;

The voltage detecting module 202 is connected to the first end of the resistor R4 for detecting the voltage of the first end of the resistor R4, and correspondingly outputting the control level signal according to the detection result;

The voltage dividing control module 203, the control end and the voltage dividing adjusting end are respectively connected to the output end of the voltage detecting module 202 and the output end of the voltage dividing module 201, for adjusting the voltage dividing direct current output by the voltage dividing module 201 according to the control level signal The voltage is adjusted such that the output level of the voltage comparison circuit 109 is correspondingly adjusted.

In the embodiment of the present invention, the current comparison circuit 108 and the voltage comparison circuit 109 form a gate circuit to adjust the voltage difference between the two electrodes of the light-emitting diode of the optocoupler U1, thereby adjusting the conduction current of the phototransistor of the optocoupler U1. The on-current of the phototransistor of the photocoupler U1 in turn affects the feedback current output by the feedback circuit 106. The feedback current directly determines the control of the switching transistor 104 by the PWM control circuit 103, thereby determining the output voltage of the transformer T1. The following is the adjustment process of the output level of the current comparison circuit 108 and the voltage comparison circuit 109 to the output voltage of the transformer T1:

When the current comparison circuit 108 or the voltage comparison circuit 109 outputs a high level, the voltage difference between the two electrodes of the light-emitting diode of the photocoupler U1 decreases, and the on-current of the phototransistor of the photocoupler U1 decreases accordingly, and the feedback circuit 106 outputs the PWM control. The feedback current of the circuit 103 is also correspondingly reduced, and the PWM control circuit 103 increases the duty ratio of the pulse signal outputted to the switching transistor 104, thereby increasing the primary voltage of the transformer T1 through the switching transistor 104, and thus the secondary of the transformer T1. The output voltage will also increase accordingly;

When the current comparison circuit 108 and the voltage comparison circuit 109 simultaneously output a low level, the voltage difference between the two electrodes of the light-emitting diode of the optocoupler U1 increases, and the on-current of the phototransistor of the photocoupler U1 increases accordingly, and the feedback circuit 106 outputs to the PWM. The feedback current of the control circuit 103 is also increased accordingly, and the PWM control circuit 103 reduces the duty ratio of the pulse signal outputted to the switching transistor 104, thereby reducing the primary voltage of the transformer T1 through the switching transistor 104, and thus the transformer T1 times. The stage output voltage will also decrease;

When the current comparison circuit 108 and the voltage comparison circuit 109 simultaneously output a high level, the voltage difference between the two electrodes of the light-emitting diode of the optocoupler U1 decreases, and the on-current of the phototransistor of the photocoupler U1 decreases accordingly, and the feedback circuit 106 outputs to the PWM. The feedback current of the control circuit 103 is also correspondingly reduced, and the PWM control circuit 103 increases the duty ratio of the pulse signal outputted to the switching transistor 104, thereby increasing the primary voltage of the transformer T1 through the switching transistor 104, and thus the transformer T1 times. The stage output voltage will also increase.

2 shows an example circuit structure of a driving power plug-in protection circuit provided in an embodiment of the present invention in a split type LED lamp. For convenience of description, only parts related to the present invention are shown, which are described in detail as follows:

As a preferred embodiment of the present invention, the voltage dividing module 201 includes a resistor R11 and a resistor R12. The first end of the resistor R11 is an input end of the voltage dividing module 201, and the second end of the resistor R11 is connected to the first end of the resistor R12. As an output terminal of the voltage dividing module 201, the second end of the resistor R12 is grounded.

As a preferred embodiment of the present invention, the voltage detecting module 202 includes:

Resistor R13, resistor R14, comparator U2, resistor R15 and capacitor C2;

The first end of the resistor R13 is the input end of the voltage detecting module 202, the second end of the resistor R13 and the first end of the resistor R14 are connected to the non-inverting input end of the comparator U2, and the second end of the resistor R14 is opposite to the comparator U2. The inverting input terminal is connected to the ground, the positive power terminal and the negative power terminal of the comparator U2 are respectively connected to the DC power source VCC and the ground, the output terminal of the comparator U2 is the output terminal of the voltage detecting module 202, and the resistor R15 is connected to the comparator U2. The output end is connected to the first end of the capacitor C2, and the second end of the capacitor C2 is connected to the inverting input terminal of the comparator U2. Among them, the output voltage of the DC power supply VCC can be +5V.

As a preferred embodiment of the present invention, the voltage dividing control module 203 includes an NPN type transistor Q1 and a resistor R16. The base of the NPN type transistor Q1 is a control terminal of the voltage dividing control module 203, and the emitter of the NPN type transistor Q1 is grounded, and the resistor R16 is The first end is connected to the collector of the NPN transistor Q1, and the second end of the resistor R16 is the voltage dividing adjustment end of the voltage dividing control module 203.

The above-mentioned driving power plug protection circuit 200 is further described below in conjunction with the working principle:

In the working principle, after the resistance values of the resistor R11 and the resistor R12 are selected, the resistor R11 and the resistor R12 divide the output voltage of the rectifying and filtering circuit 107, and the output voltage is reduced to half of the rated voltage of the LED, and the driving power source is driven. The output voltage of 200 at no load is only half of the rated voltage of the LED. When the user first connects the driving power source 200 to the alternating current but does not connect it to the LED light board, the output voltage of the driving power source 200 (half the rated voltage of the LED) is loaded at the input end LED+ of the LED at the moment of completing the connection, thus There is no damage to the LED, and at this time, the LED on the LED lamp board has a current passing through, and a voltage drop is generated on the current detecting resistor R7, and the voltage drop is applied to the inverting input terminal of the current comparing circuit 108 through the resistor R10-, The resistor R1 and the resistor R2 divide the voltage of the LED+ at the input end of the LED lamp board, and then input the non-inverting input terminal of the voltage comparison circuit 109, and at the same time, the common contact of the resistor R2 and the resistor R3 also generates a divided DC power. The two voltages of the direct current are respectively passed through the resistor R4 and the resistor R13 into the non-inverting input terminal of the current comparison circuit 108 and the non-inverting input terminal of the comparator U2. When the voltage of the divided DC power is greater than the voltage of the inverting input terminal of the comparator U2, Comparator U2 will output a high level to control the NPN transistor Q1 to conduct, and then the NPN transistor Q1 pulls current from the common junction of the resistor R11 and the resistor R12 through the resistor R16, and at the same time, due to the resistor R16 and the resistor R 12 parallel, so the common point of the resistor R11 and the resistor R12 will be reduced, then the voltage comparison circuit 109 will output a high level, and then the voltage difference between the two poles of the light-emitting diode of the optocoupler U1 is reduced by the resistor R9 and the diode D3. Then, the on-current of the phototransistor of the photocoupler U1 is correspondingly reduced, and the feedback current fed back to the PWM control circuit 103 by the feedback circuit 106 is also reduced, so the PWM control circuit 103 increases the duty of the pulse signal outputted by the PWM control circuit 103. In this way, the primary voltage of the transformer T1 can be increased by the switching transistor 104, thereby increasing the secondary output voltage of the transformer T1 (here, when the rated voltage of the LED is not reached), thereby steadily increasing the output to the LED panel. The voltage causes the LED to operate in a constant current state.

The embodiment of the invention adopts a driving power plug-in protection circuit including a voltage dividing module, a voltage detecting module and a voltage dividing control module in the split type LED lamp, and when the driving power source is not connected to the LED light board but has been connected to the alternating current power supply, The output voltage of the rectifying and filtering circuit is stepped down by the voltage dividing module, and after the driving power source and the LED lamp board are connected, the voltage of the first end of the resistor R4 is detected by the voltage detecting module, and then the control level is driven accordingly. The voltage dividing control module adjusts the voltage of the divided DC power output by the voltage dividing module to adjust the output level of the voltage comparison circuit accordingly, thereby controlling the feedback current of the driving power source so that the PWM control circuit of the driving power source is based on the feedback current The constant current drive is realized for the LED light board, so that the connection between the driving power source and the LED light board is not ensured, and the LED does not shorten the service life due to overcurrent.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

A driving power plugging and unplugging protection circuit of a split type LED lamp is connected with a rectifying and filtering circuit of a driving power source, a voltage dividing resistor R1, a voltage dividing resistor R2, a voltage dividing resistor R3, a resistor R4 and a voltage comparing circuit, and the voltage dividing resistor R1 is connected between the output end of the rectifying and filtering circuit and the first end of the voltage dividing resistor R2, and the voltage dividing resistor R2 and the voltage dividing resistor R3 are connected to the first end of the resistor R4. The second end of the resistor R4 is connected to the non-inverting input terminal of the current comparison circuit, and the output level of the voltage comparison circuit and the output level of the current comparison circuit are common to the feedback output of the feedback circuit of the driving power source. The current control is performed, so that the PWM control circuit of the driving power supply adjusts the output voltage of the transformer T1 of the driving power source according to the feedback current; wherein the driving power plugging protection circuit comprises:

a voltage dividing module, wherein the input end and the output end are respectively connected to an output end of the rectifying and filtering circuit and an inverting input end of the voltage comparing circuit, and configured to perform a voltage dividing process on the DC power output by the rectifying and filtering circuit to reduce the The voltage of the direct current, and output a partial voltage direct current;

a voltage detecting module, the input end is connected to the first end of the resistor R4, for detecting the voltage of the first end of the resistor R4, and correspondingly outputting a control level signal according to the detection result;

a voltage dividing control module, a control end and a voltage dividing adjusting end respectively connected to an output end of the voltage detecting module and an output end of the voltage dividing module, configured to adjust a voltage of the voltage dividing direct current according to the control level signal The output level of the voltage comparison circuit is adjusted accordingly.
The driving power supply plugging and unplugging protection circuit of claim 1 , wherein the voltage dividing module comprises a resistor R11 and a resistor R12, and the first end of the resistor R11 is an input end of the voltage dividing module, A common junction of the second end of the resistor R11 and the first end of the resistor R12 serves as an output of the voltage dividing module, and a second end of the resistor R12 is grounded.
The driving power supply plugging and unplugging protection circuit of claim 1 , wherein the voltage detecting module comprises:

Resistor R13, resistor R14, comparator, resistor R15 and capacitor C2;

The first end of the resistor R13 is an input end of the voltage detecting module, and the second end of the resistor R13 and the first end of the resistor R14 are connected to the non-inverting input end of the comparator, the resistor The second end of the R14 is connected to the inverting input end of the comparator, and the positive power terminal and the negative power terminal of the comparator are respectively connected to the DC power source and the ground, and the output end of the comparator is An output terminal of the voltage detecting module, the resistor R15 is connected between the output end of the comparator and the first end of the capacitor C2, and the second end of the capacitor C2 is connected to the inverting input of the comparator end.
The driving power supply plug-and-pull protection circuit according to claim 1, wherein the voltage dividing control module comprises an NPN type transistor Q1 and a resistor R16, and the base of the NPN type transistor Q1 is controlled by the voltage dividing control module. The emitter of the NPN transistor Q1 is grounded, the first end of the resistor R16 is connected to the collector of the NPN transistor Q1, and the second end of the resistor R16 is a voltage divider of the voltage dividing control module. Adjust the end.
A split type LED lamp comprising an LED lamp board and a driving power source, wherein the split type LED lamp further comprises a driving power plugging and unplugging protection circuit, and the driving power plugging protection circuit and the driving power source are rectified The filter circuit, the voltage dividing resistor R1, the voltage dividing resistor R2, the voltage dividing resistor R3, the resistor R4, and the voltage comparison circuit are connected, and the voltage dividing resistor R1 is connected to the output end of the rectifying and filtering circuit and the voltage dividing resistor R2. Between the first ends, the voltage dividing resistor R2 and the voltage dividing resistor R3 are connected to the first end of the resistor R4, and the second end of the resistor R4 is connected to the non-inverting input terminal of the current comparing circuit. The output level of the voltage comparison circuit and the output level of the current comparison circuit jointly control a feedback current output by the feedback circuit of the driving power supply, so that the PWM control circuit of the driving power supply adjusts according to the feedback current An output voltage of the transformer T1 driving the power source;

The driving power plugging protection circuit includes:

a voltage dividing module, wherein the input end and the output end are respectively connected to an output end of the rectifying and filtering circuit and an inverting input end of the voltage comparing circuit, and configured to perform a voltage dividing process on the DC power output by the rectifying and filtering circuit to reduce the The voltage of the direct current, and output a partial voltage direct current;

a voltage detecting module, the input end is connected to the first end of the resistor R4, for detecting the voltage of the first end of the resistor R4, and correspondingly outputting a control level signal according to the detection result;

a voltage dividing control module, a control end and a voltage dividing adjusting end respectively connected to an output end of the voltage detecting module and an output end of the voltage dividing module, configured to adjust a voltage of the voltage dividing direct current according to the control level signal The output level of the voltage comparison circuit is adjusted accordingly.
The split type LED lamp of claim 5, wherein the voltage dividing module comprises a resistor R11 and a resistor R12, a first end of the resistor R11 is an input end of the voltage dividing module, and the resistor R11 The common end of the second end and the first end of the resistor R12 serves as the output end of the voltage dividing module, and the second end of the resistor R12 is grounded.
The split LED lamp of claim 5, wherein the voltage detecting module comprises:

Resistor R13, resistor R14, comparator, resistor R15 and capacitor C2;

The first end of the resistor R13 is an input end of the voltage detecting module, and the second end of the resistor R13 and the first end of the resistor R14 are connected to the non-inverting input end of the comparator, the resistor The second end of the R14 is connected to the inverting input end of the comparator, and the positive power terminal and the negative power terminal of the comparator are respectively connected to the DC power source and the ground, and the output end of the comparator is An output terminal of the voltage detecting module, the resistor R15 is connected between the output end of the comparator and the first end of the capacitor C2, and the second end of the capacitor C2 is connected to the inverting input of the comparator end.
The split type LED lamp of claim 5, wherein the voltage dividing control module comprises an NPN type transistor Q1 and a resistor R16, and the base of the NPN type transistor Q1 is substantially the control end of the voltage dividing control module. The emitter of the NPN transistor Q1 is grounded, the first end of the resistor R16 is connected to the collector of the NPN transistor Q1, and the second end of the resistor R16 is the voltage dividing adjustment terminal of the voltage dividing control module. .