WO2021120561A1

WO2021120561A1 - Hot-pluggable led driving power supply and control method therefor

Info

Publication number: WO2021120561A1
Application number: PCT/CN2020/096928
Authority: WO
Inventors: 毛昭祺; 王纪周; 柯乃泉
Original assignee: 毛昭祺
Priority date: 2019-12-16
Filing date: 2020-06-19
Publication date: 2021-06-24
Also published as: CN111065184B; CN111065184A

Abstract

Disclosed in the present invention are a hot-pluggable LED driving power supply and a control method therefor. Said driving power supply comprises: a main circuit, a switch transistor S2, a main control circuit, a sub-control circuit and a resistor R1; the main circuit comprises a switch transistor S1, and the main circuit processes power-level energy conversion under the control of the main control circuit 2 and supplies same to an LED load 8; an input end of the main control circuit 2 is connected to an output end of the main circuit 1, a control end of the main control circuit 2 is connected to the sub-control circuit 3, and an output end of the main control circuit 2 is connected to a control end of the switch transistor S1; the switch transistor S2 is connected in series between the main circuit 1 and the LED load 8, and a control end of the switch transistor S2 is connected to the sub-control circuit 3; and the resistor R1 is connected in parallel to the switch transistor S2. In the present invention,the switch transistor S2, the resistor R1 and the sub-control circuit are added at the output end of the driving power supply, avoiding the problem of light flashing caused by the no-load voltage outputted by the driving power supply being greater than the voltage of an LED lamp in cases where the LED lamp load is unplugged while being energized and is replugged while being energized.

Description

Hot-swappable LED driving power supply and control method thereof

Technical field

The invention relates to the technical field of power supplies, in particular to a hot-swappable LED driving power supply and a control method thereof.

Background technique

The output of the driving power supply usually carries an LED lamp load. In the existing driving power supply design, the no-load voltage of the driving power supply is greater than the voltage of the LED lamp, thereby lighting the LED lamp. The marketization of LED lights has successfully lighted every bridge, every avenue, every building, and even every household. As a result, the visual effect of LED lights will be paid more and more attention. In actual use, there will be loads of LED lights. Unplug it when it is charged and plug it in when it is charged. Since the voltage of the drive power control circuit is greater than the voltage of the LED lamp, the problem of flashing lights will affect the visual effect in an instant. Therefore, there is an urgent need for an LED drive power supply, so that the LED lamp is unplugged when it is charged, and the problem of lamp flicker will not occur.

For example, a kind of "a split-type LED lamp and its driving power plug-in protection circuit" disclosed in Chinese patent documents, its publication number CN103037585B, its publication date December 17, 2014, includes the rectification and filtering of the driving power supply The 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 terminal of the rectifier filter circuit and the first voltage dividing resistor R2. Between one end, the voltage dividing resistor R2 and the voltage dividing resistor R3 are commonly connected to the first end of the resistor R4, and the second end of the resistor R4 is connected to the non-inverting input end of the current comparing circuit. The output level of the voltage comparison circuit and the output level of the current comparison circuit jointly control the feedback current output by the feedback circuit of the driving power supply, so that the PWM control circuit of the driving power supply adjusts the feedback current according to the feedback current. The output voltage of the transformer T1 of the drive power supply; the drive power plug-in protection circuit includes: a voltage divider module, the input terminal and the output terminal are respectively connected to the output terminal of the rectification filter circuit and the inverting input terminal of the voltage comparison circuit , Used to divide the DC power output by the rectification filter circuit to reduce the voltage of the DC power, and output a divided DC power; the voltage detection module, the input terminal is connected to the first end of the resistor R4 for The voltage at the first end of the resistor R4 is detected, and a control level signal is output correspondingly according to the detection result; the voltage division control module, the control end and the voltage division adjustment end are respectively connected to the output end of the voltage detection module and the The output terminal of the voltage dividing module is used to adjust the voltage of the divided DC power according to the control level signal so that the output level of the voltage comparison circuit is adjusted accordingly; the voltage detection module includes: a resistor R13, A resistor R14, a comparator, a resistor R15, and a capacitor C2; the first end of the resistor R13 is the input end of the voltage detection module, and the second end of the resistor R13 and the first end of the resistor R14 are commonly connected to The non-inverting input terminal of the comparator, the second terminal of the resistor R14 and the inverting input terminal of the comparator are commonly connected to ground, and the positive power terminal and the negative power terminal of the comparator are respectively connected to the DC power supply And ground, the output terminal of the comparator is the output terminal of the voltage detection module, the resistor R15 is connected between the output terminal of the comparator and the first terminal of the capacitor C2, The second terminal is connected to the inverting input terminal of the comparator. Through the voltage detection module and the voltage divider control module, the voltage delivered by the LED driving power supply to the LED is detected and controlled, but it still does not solve the problem. In the case of electric power, when the LED lamp is unplugged, the output no-load voltage of the driving power supply is greater than the LED lamp voltage. Flashing problem

Summary of the invention

The invention mainly solves the problem that the existing technology cannot solve the problem that the LED lamp is unplugged and then plugged in when the LED lamp is charged; it provides a hot-swappable LED driving power supply and a control method thereof, and solves the problem that the LED lamp is charged If it is unplugged and reconnected under live condition, the light flickering problem occurs because the output no-load voltage of the drive power supply is greater than the voltage of the LED light.

The above technical problems of the present invention are mainly solved by the following technical solutions: a hot-swappable LED drive power supply, including a main circuit, a switch tube S2, a main control circuit, a sub-control circuit and a resistor R1, the main The circuit includes a switch S1. The main circuit processes the energy conversion of the power stage and supplies the LED load under the control of the main control circuit; the input end of the main control circuit is connected to the output end of the main circuit for Sampling the output voltage of the main circuit, the control end of the main control circuit is connected to the sub-control circuit, the output end of the main control circuit is connected to the control end of the switch tube S1; the switch tube S2 is connected in series Between the main circuit and the LED load, the control terminal of the switch tube S2 is connected to the sub-control circuit; the resistor R1 is connected in parallel to the switch tube S2; the sub-control circuit includes a first sampling terminal , A second sampling terminal, a first output terminal and a second output terminal, the first sampling terminal samples the output voltage of the main circuit, the second sampling terminal samples the voltage of the resistor R1, the first output Terminal is connected to the main control circuit, and the second output terminal is connected to the switch S2. When the sub-control circuit detects that the output voltage of the main circuit exceeds a third preset value, the control switch S2 is turned off When it is detected that the voltage of the resistor R1 exceeds the fourth preset value, and at the same time it is detected that the output voltage of the main circuit exceeds the third preset value, the output voltage of the main circuit is controlled by controlling the main control circuit Lower, and control the switch tube S2 to close. The output voltage V0 of the main circuit is detected by the sub-control circuit, and the switching tube S2 is controlled to be turned off. By detecting the voltage of the resistor R1, the switching tube S2 is controlled to close, and the switching tube S2 is controlled to turn on and off to make the main circuit and the LED load. When the LED load is unplugged when the LED load is charged, the connection between the output of the main circuit and the LED load is disconnected; when the LED load is plugged in again when the LED load is charged, the sub-control circuit controls the main control circuit , Through the main control circuit to control the main circuit to first reduce the no-load voltage output by the main circuit, then close the connection between the output of the main circuit and the LED load, and then adjust the no-load voltage output by the main circuit, thereby avoiding LED lights When plugged in under the condition of electrification, because the no-load voltage of the driving power supply is greater than the voltage of the LED lamp, the problem of flashing of the lamp will occur in an instant.

Preferably, the impedance of the resistor R1 is several or several tens of times the impedance of the LED load. By setting the impedance of resistor R1 to be several or tens of times the impedance of the LED load, the sub-control circuit can better detect the LED load when detecting the voltage of resistor R1, and it is convenient to adjust the no-load output of the main circuit. Voltage.

Preferably, the main control circuit includes a drive circuit, a photoelectric coupling circuit, and a voltage loop. The input end of the voltage loop is connected to the output end of the main circuit, and the output end of the voltage loop is connected to the input end of the drive circuit. , The output terminal of the driving circuit is connected to the switch tube S1 via the photoelectric coupling circuit. The rated value of the output voltage V0 of the main circuit is set through the voltage loop, the output voltage V0 of the main circuit is adjusted, and the drive circuit and the main circuit are electrically isolated through the photoelectric coupling circuit to effectively protect the circuit.

Preferably, the voltage loop includes an operational amplifier US1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C1, and a switch tube S3. The non-inverting input terminal of the operational amplifier US1 inputs the first voltage reference signal Vref1, so One end of the resistor R3 is connected to the output positive end of the main circuit, the other end of the resistor R3 is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to the negative phase input end of the operational amplifier US1 , The first end of the capacitor C1 and one end of the resistor R5 are connected, the second end of the capacitor C1 is connected to one end of the resistor R2, and the output end of the operational amplifier US1 is respectively connected to the other end of the resistor R2 and the driver The input end of the circuit is connected, the other end of the R5 is grounded, the switch S3 is connected in parallel to the resistor R3, and the control end of the switch S3 is connected to the sub-control circuit as the control end of the main control circuit. The input signal of the negative phase end of the operational amplifier US1 is divided by the resistor R3, the resistor R4 and the resistor R5 to the output voltage Vo of the main circuit. The input signal of the phase end and the first voltage reference signal Vref1 of the positive phase end are differentially amplified and output a feedback signal for transmission to the drive circuit. The drive circuit outputs a drive signal through the photoelectric coupling circuit to control the switch tube S1 of the main circuit. On and off, the output voltage of the main circuit is controlled by the on and off of the switch tube S1. The rated value of the output voltage V0 of the main circuit is set by the first voltage reference signal Vref1, the resistor R3, the resistor R4, and the resistor R5. When the switch tube S3 receives When the output signal of the sub-control circuit closes, the set value of the output voltage V0 of the main circuit becomes smaller, and the first voltage reference signal Vref1 of the positive-phase input terminal of the operational amplifier US1 is combined with the input signal of the negative-phase input terminal. After the differential operation, the first feedback signal is output to the driving circuit, and the driving circuit outputs the driving signal to the main circuit, so that the output voltage V0 of the main circuit becomes smaller. When the switch S3 receives the output signal of the sub-control circuit, it turns off When it is turned on, the set value of the output voltage V0 of the main circuit returns to the rated value, and the first feedback signal is output to the drive circuit after the differential operation of the first voltage reference signal Vref1 at the positive input terminal of the operational amplifier US1 and the input signal at the negative input terminal. , The drive circuit outputs the drive signal to the main circuit, so that the output voltage V0 of the main circuit returns to the rated value.

Preferably, the voltage loop includes an operational amplifier US2, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a capacitor C2, and a switch tube S4, and one end of the resistor R7 is connected to the output terminal of the main circuit , The other end of the resistor R7 is connected to the negative input end of the operational amplifier US2, the first end of the capacitor C2, and one end of the resistor R8, and the second end of the capacitor C2 is connected to one end of the resistor R6, so The output end of the operational amplifier US2 is respectively connected to the other end of the resistor R6 and the input end of the drive circuit, the other end of the resistor R8 is connected to the ground; one end of the resistor R9 inputs the second voltage reference signal Vref2, so The other end of the resistor R9 is connected to the non-inverting input end of the operational amplifier US2 as a common end, the common end is connected to one end of the resistor R10 and the resistor R11, and the other end of the resistor R11 is connected to the ground. The other end of the resistor R10 is connected to one end of the switch tube S4, the other end of the switch tube S4 is connected to ground, and the control end of the switch tube S4 is connected to the sub-control circuit. The input signal of the negative input terminal of the operational amplifier US2 is obtained by dividing the output voltage V0 of the main circuit by resistor R7 and resistor R8, and the input signal of the positive input terminal of the operational amplifier US2 is second The voltage reference signal Vref2 is voltage-divided. Through a compensation network composed of a resistor R6 and a capacitor C2, the operational amplifier US2 differentially amplifies the input signal at the negative phase terminal and the input signal at the positive phase terminal and outputs a second feedback signal to the drive circuit. The driving circuit is made to output a driving signal to the main circuit, so that the output voltage V0 of the main circuit becomes smaller and returns to the rated value.

Preferably, the sub-control circuit includes a comparator US3, a comparator US4, an RS flip-flop A1, an RS flip-flop A2, an RS flip-flop A3, an AND circuit AND, a first delay circuit and a second delay circuit. The positive phase input terminal of the US3 is connected to the output terminal of the main circuit, the negative phase input terminal of the comparator US3 inputs the third voltage reference signal Vref3, and the output terminal of the comparator US3 is connected to the S of the RS flip-flop A1. The Q terminal of the RS flip-flop A1 is connected to the input terminal of the first delay circuit and the R terminal of the RS flip-flop A3, respectively, the output terminal of the first delay circuit and the first input terminal of the AND circuit AND Connected, the positive phase input terminal of the comparator US4 inputs the voltage sampling value of the resistor R1, the negative phase input terminal of the comparator US4 inputs the fourth voltage reference signal Vref4, the output terminal of the comparator US4 and the AND circuit The second input terminal of the AND is connected, the output terminal of the AND circuit AND is connected to the S terminal of the RS flip-flop A2, and the Q terminal of the RS flip-flop A3 is respectively connected to the R terminal of the RS flip-flop A1 and the RS flip-flop A2. The R terminal of the RS flip-flop A3 is connected to the control terminal of the switch S2, the S terminal of the RS flip-flop A3 is connected to the output terminal of the second delay circuit, and the Q terminal of the RS flip-flop A2 is connected to the input terminal of the second delay circuit and The control terminal of the main control circuit is connected. When the R terminal of RS flip-flop A1, RS flip-flop A2, and RS flip-flop A3 receives a trigger, the output Q terminal is set low, when the S terminal receives a trigger, the output Q terminal is set high, and the first delay circuit and the second delay circuit pair the input The signal is delayed; when the LED load is disconnected when the LED driver is working normally, the voltage at the positive phase terminal of the comparator US3 is higher than the voltage at the negative phase terminal, and a high level is output to the R terminal of the trigger A1. The Q terminal of A1 outputs a high level to the first delay circuit and the flip-flop A3. When the R terminal of the flip-flop A3 receives a high level, the Q terminal outputs a low level VX2 to the switching tube S2, and the switching tube S2 is turned off. On, the main circuit is disconnected from the LED load; the first terminal of the AND gate is input with a high level. Since the LED load is unplugged, there is no voltage between the resistor R1 and the LED load, and the positive phase terminal of the comparator US4 is lower than the negative At the phase end, the comparator US4 outputs a low level, and the AND gate does not work; when the LED load is reconnected when the LED driver is working normally, the voltage rises to fourth because the LED load is reconnected to the resistor R1 Voltage reference signal Vref4, the positive phase terminal of the comparator US4 is higher than the negative phase terminal, the comparator US4 outputs a high level, and the AND gate AND operation outputs a high level to the S terminal of the flip-flop A2, and the Q terminal of the flip-flop A2 outputs The high level is applied to the second delay circuit and the switching tube S3 or the switching tube S4 of the voltage loop in the main control circuit. The closing of the switching tube S3 or the switching tube S4 of the voltage loop in the sub-control circuit reduces the output voltage of the main circuit. Vo, the second delay circuit transmits the high level output by the flip-flop A2 to the S terminal of the flip-flop A3 after a delay, and the Q terminal of the flip-flop A3 outputs a high level to the R of the flip-flop A1 Terminal and the switching tube S2, the switching tube S2 is turned on, and at the same time the flip-flop A1 outputs a low level so that the AND gate outputs a low level, then the Q terminal of the flip-flop A2 outputs a low level, turning off the The switch tube S3 or the switch tube S4 of the voltage loop in the main control circuit, the output voltage V0 is restored to the rated value; it prevents the lamp flicker problem when the LED is plugged in under live conditions, and the no-load voltage of the driving power supply is greater than the LED load voltage. .

The present invention also provides a hot-pluggable LED drive power control method, including the following steps: S01: sampling the output voltage of the main circuit; S02: sampling the voltage of the resistor R1; S03: judging the output voltage of the main circuit Whether it exceeds the third voltage reference signal Vref3, if the judgment is yes, go to step S04, if the judgment is no, then go back to step S03; S04: turn off the switch S2; S05: judge whether the voltage of the resistor R1 exceeds the fourth voltage reference signal Vref4, when the judgment is yes, go to step S06, if the judgment is no, then go back to step S03; S06: reduce the output voltage of the main circuit; S07: close the switch S2; S08: increase the output voltage of the main circuit to the rated value. Through the control method of steps S01 to S08, the problem that the no-load voltage output by the driving power supply is greater than the LED load voltage is solved, and the LED flashing is prevented.

Preferably, in the step S08, the calculation formula of the rated value of the output voltage of the main circuit is:

Among them, V1 is the rated value of the output voltage of the main circuit. When the resistor R3 is short-circuited by the switch S3, the output voltage V0 of the main circuit decreases. When the resistor R3 is not short-circuited, the output voltage V0 of the main circuit returns to the rated value.

Among them, Z1 is the parallel resistance value of the resistor R10 and the resistor R11, V3 is the voltage value input by the non-inverting input terminal of the operational amplifier US2, and V1 is the rated output voltage of the main circuit. When the switching tube S4 is closed, the resistance R10 and the resistance R11 are connected in parallel, and the output voltage V0 of the main circuit is reduced. When the switching tube S4 is opened, the resistance R10 and the resistance R11 are not connected in parallel, and the output voltage V0 of the main circuit will have a rated value.

The beneficial effects of the present invention are: by adding a switch tube S2, a resistor R1 and a sub-control circuit at the output end of the driving power supply, the switch tube S2 is first disconnected after the LED load is unplugged, so that the output of the driving power supply is disconnected from the LED load ; When reconnecting the LED load, first reduce the output voltage of the drive power supply, and then close the switch S2, and then make the output voltage of the drive power return to the original output voltage after the switch S2 is closed, so as to realize the reconnection of the LED load When the LED lamp current starts to rise from a small value to the rated value, it is avoided that the LED lamp load is unplugged and reconnected when it is charged. Since the no-load voltage of the drive power supply is greater than the voltage of the LED lamp, in an instant There will be a problem of flashing lights.

Description of the drawings

Fig. 1 is a circuit block diagram of the LED driving power supply of the first embodiment.

Fig. 2 is a schematic diagram of the circuit connection of the voltage loop of the first embodiment.

Fig. 3 is a schematic diagram of the circuit connection of the voltage loop of the second embodiment.

Fig. 4 is a schematic diagram of the circuit connection of the sub-control circuit of the first embodiment.

Fig. 5 is a flowchart of a method for controlling an LED driving power supply of the present invention.

In the figure 1. Main circuit, 2. Main control circuit, 3. Sub control circuit, 4. Drive circuit, 5. Voltage loop, 6. First delay circuit, 7. Second delay circuit, 8. LED load.

Detailed ways

In the following, the technical solution of the present invention will be further described in detail through the embodiments and in conjunction with the accompanying drawings.

Embodiment 1: A hot-swappable LED drive power supply, as shown in Figure 1, includes a main circuit 1, a switch tube S2, a main control circuit 2, a sub-control circuit 3, and a resistor R1. The main circuit 1 includes a switch tube S1 , The main circuit 1 processes the energy conversion of the power stage and supplies it to the LED load 8 under the control of the main control circuit 2; the input end of the main control circuit 2 is connected to the output end of the main circuit 1 for sampling the output voltage of the main circuit 1, The control terminal of the main control circuit 2 is connected to the sub-control circuit 3, and the output terminal of the main control circuit 2 is connected to the control terminal of the switch tube S1; the switch tube S2 is connected in series between the main circuit 1 and the LED load 8, and the switch tube S2 is controlled The terminal is connected to the sub-control circuit 3; the resistor R1 is connected in parallel to the switch S2; the sub-control circuit 3 includes a first sampling terminal, a second sampling terminal, a first output terminal, and a second output terminal. The first sampling terminal samples the main circuit 1 The second sampling terminal samples the voltage of the resistor R1, the first output terminal is connected to the main control circuit 2, the second output terminal is connected to the switch S2, the sub-control circuit detects that the output voltage of the main circuit exceeds the third preset value When it is detected that the voltage of the resistor R1 exceeds the fourth preset value and at the same time it is detected that the output voltage of the main circuit exceeds the third preset value, the output voltage of the main circuit is controlled by controlling the main control circuit Reduce and control the switch tube S2 to close. The impedance of the resistor R1 is several or tens of times the LED load impedance. The main control circuit 2 includes the drive circuit 4, the photoelectric coupling circuit and the voltage loop 5. The input terminal of the voltage loop 5 and the main The output end of the circuit 1 is connected, the output end of the voltage loop 5 is connected to the input end of the drive circuit 4, and the output end of the drive circuit 4 is connected to the switch tube S1 via the photoelectric coupling circuit.

As shown in Figure 2, the voltage loop 5 includes an operational amplifier US1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C1, and a switch tube S3. The non-inverting input terminal of the operational amplifier US1 inputs the first voltage reference signal Vref1, and the resistor One end of R3 is connected to the output positive end of the main circuit 1, the other end of the resistor R3 is connected to one end of the resistor R4, and the other end of the resistor R4 is connected to the negative input end of the operational amplifier US1, the first end of the capacitor C1 and the resistor R5. One end is connected, the second end of the capacitor C1 is connected to one end of the resistor R2, the output end of the operational amplifier US1 is respectively connected to the other end of the resistor R2 and the input end of the driving circuit 4, the other end of R5 is grounded, and the switch S3 is connected in parallel to the resistor On R3, the control terminal of the switch S3 is connected to the sub-control circuit 3 as the control terminal of the main control circuit 2.

As shown in FIG. 4, the sub-control circuit 3 includes a comparator US3, a comparator US4, an RS flip-flop A1, an RS flip-flop A2, an RS flip-flop A3, an AND circuit AND, a first delay circuit 6 and a second delay circuit 7. , The positive phase input terminal of the comparator US3 is connected to the output terminal of the main circuit 1, the negative phase input terminal of the comparator US3 inputs the third voltage reference signal Vref3, and the output terminal of the comparator US3 is connected to the S terminal of the RS flip-flop A1, The Q terminal of the RS flip-flop A1 is connected to the input terminal of the first delay circuit 6 and the R terminal of the RS flip-flop A3, the output terminal of the first delay circuit 6 is connected to the first input terminal of the AND circuit AND, and the comparator US4 The positive phase input terminal of the comparator US4 receives the voltage sampling value of the resistor R1, the negative phase input terminal of the comparator US4 inputs the fourth voltage reference signal Vref4, the output terminal of the comparator US4 is connected with the second input terminal of the AND circuit AND, and the circuit The output terminal of AND is connected to the S terminal of the RS flip-flop A2, the Q terminal of the RS flip-flop A3 is connected to the R terminal of the RS flip-flop A1, the R terminal of the RS flip-flop A2 and the control terminal of the switch S2 respectively, and the RS flip-flop The S terminal of A3 is connected to the input terminal of the second delay circuit 7, and the Q terminal of the RS flip-flop A2 is connected to the output terminal of the second delay circuit 7 and the main control circuit 2 respectively. The third voltage reference signal Vref3 is used to set a third preset value, and the fourth voltage reference signal Vref4 is used to set a fourth preset value.

In a specific application, when the LED load 8 is disconnected when the LED driver is working normally, the voltage at the positive phase terminal of the comparator US3 is higher than the voltage at the negative phase terminal, and the high level is output to the R terminal of the trigger A1. The Q terminal of A1 outputs a high level to the first delay circuit 6 and the trigger A3. When the R terminal of the trigger A3 receives a high level, the Q terminal outputs a low level to the switching tube S2, the switching tube S2 is disconnected, and the main circuit 1 is disconnected from the LED load 8; the first terminal of the AND gate inputs a high level, because the LED load 8 is unplugged, and there is no voltage between the resistor R1 and the LED load 8, the positive phase terminal of the comparator US4 is lower than the negative phase terminal , The comparator US4 outputs a low level, and the AND gate does not work; when the LED load 8 is reconnected when the LED driver is working normally, because the LED load 8 is reconnected to the resistor R1, the voltage rises to the fourth The voltage reference signal Vref4, the positive phase terminal of the comparator US4 is higher than the negative phase terminal, the comparator US4 outputs a high level, and the AND gate AND works, and outputs a high level to the S terminal of the flip-flop A2 and the Q terminal of the flip-flop A2 Output high level to the second delay circuit 7 and the switch tube S3 of the voltage loop 5 in the main control circuit 2, the switch tube S3 is closed, the input signal of the negative phase terminal of the operational amplifier US1 is connected to the main by the resistor R3, the resistor R4 and the resistor R5. The output voltage Vo of circuit 1 is divided into voltage. Through a compensation network composed of resistor R2 and capacitor C1, operational amplifier US1 performs differential operational amplification between the input signal at the negative phase terminal and the first voltage reference signal Vref1 at the positive phase terminal and outputs the feedback signal for transmission To the driving circuit 4, the driving circuit 4 controls the on-off of the switch tube S1 of the main circuit 1 through the photoelectric coupling circuit, and controls the output voltage of the main circuit 1 through the on-off of the switch tube S1, and the output voltage of the main circuit 1 is V0. The rated value is set by the first voltage reference signal Vref1, resistor R3, resistor R4 and resistor R5. When the switch tube S3 receives the output signal of the sub-control circuit 3 to make it closed, the set value of the output voltage V0 of the main circuit 1 changes Small, through the differential operation of the first voltage reference signal Vref1 at the positive input terminal of the operational amplifier US1 and the input signal at the negative input terminal, the first feedback signal is output to the drive circuit 4, and the drive circuit 4 outputs the drive signal to the main circuit 1, so that the main The output voltage V0 of the circuit 1 becomes smaller, and the second delay circuit 7 transmits the high level output by the flip-flop A2 to the S terminal of the flip-flop A3 after a delay, and the Q terminal of the flip-flop A3 outputs a high level to the R of the flip-flop A1. Terminal and the switch tube S2, the switch tube S2 is turned on, at the same time the trigger A1 outputs a low level so that the AND gate outputs a low level, then the Q terminal of the trigger A2 outputs a low level, disconnecting the voltage loop 5 in the main control circuit 2 The switch tube S3 and the resistor R3 are no longer short-circuited, and the output voltage V0 of the main circuit 1 returns to the rated value. The first voltage reference signal Vref1 at the positive phase input terminal of the operational amplifier US1 and the input signal at the negative phase input terminal are output after the differential operation A feedback signal is sent to the drive circuit 4, and the drive circuit 4 outputs the drive signal to the main circuit 1, so that the main power The output voltage V0 of circuit 1 returns to the rated value. The switch tube S3 in this embodiment can also be connected in parallel to both ends of the resistor R4.

The second embodiment is a hot-swappable LED driving power supply. As shown in Figure 3, the voltage loop 5 includes an operational amplifier US2, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a capacitor C2, and Switch S4, one end of the resistor R7 is connected to the output end of the main circuit 1, the other end of the resistor R7 is respectively connected to the negative input end of the operational amplifier US2, the first end of the capacitor C2, and one end of the resistor R8. The first end of the capacitor C2 The two ends are connected to one end of the resistor R6, the output end of the operational amplifier US2 is respectively connected to the other end of the resistor R6 and the input end of the drive circuit 4, the other end of the resistor R8 is connected to the ground; one end of the resistor R9 inputs the second voltage reference signal Vref2, the other end of resistor R9 is connected to the non-inverting input end of operational amplifier US2 as a common end, the common end is connected to one end of resistor R10 and resistor R11, the other end of resistor R11 is connected to ground, and the other end of resistor R10 is connected to the switch tube One end of S4 is connected, the other end of the switch S4 is connected to the ground, and the control end of the switch S4 is connected to the sub-control circuit 3. The rest of the circuit is the same as the first embodiment. Compared with the first embodiment, this embodiment adjusts the input signal of the non-inverting input terminal of the operational amplifier US2 through whether the resistor R10 and the resistor R11 are connected in parallel, and the voltage signal has a larger adjustment range. The switch S4 in this embodiment can also be connected in series with the resistor R11.

As shown in Figure 5, it is a hot-swappable LED drive power control method of the present invention, including the following steps: S01: sampling the output voltage of the main circuit 1; S02: sampling the voltage of the resistor R1; S03: judging the main Whether the output voltage of circuit 1 exceeds the third voltage reference signal Vref3, if the judgment is yes, go to step S04, if the judgment is no, then go back to step S03; S04: turn off the switch S2; S05: judge whether the voltage of the resistor R1 exceeds the first Four voltage reference signal Vref4, when the judgment is yes, go to step S06, if judgment is no, then go back to step S03; S06: reduce the output voltage of the main circuit 1; S07: close the switch S2; S08: increase the output voltage of the main circuit 1 To the rated value.

In the first embodiment, the calculation formula of the rated value of the output voltage of the main circuit 1 is:

Among them, V1 is the rated value of the output voltage of the main circuit 1.

In the second embodiment, the calculation formula of the rated value of the output voltage of the main circuit 1 is:

Among them, Z1 is the parallel resistance value of the resistor R10 and the resistor R11, V3 is the voltage value input by the non-inverting input terminal of the operational amplifier US2, and V1 is the rated value of the output voltage of the main circuit 1.

The above-mentioned embodiment is only a preferred solution of the present invention, and does not limit the present invention in any form. There are other variations and modifications under the premise of not exceeding the technical solution described in the claims.

Claims

A hot-swappable LED drive power supply, which is characterized in that it comprises

The main circuit, the switch tube S2, the main control circuit, the sub-control circuit and the resistor R1, the main circuit includes the switch tube S1, the main circuit processes the energy conversion of the power stage and supplies the LED load under the control of the main control circuit ；

The input end of the main control circuit is connected to the output end of the main circuit for sampling the output voltage of the main circuit, the control end of the main control circuit is connected to the sub-control circuit, and the main control circuit The output terminal of is connected with the control terminal of the switch tube S1;

The switch tube S2 is connected in series between the main circuit and the LED load, and the control end of the switch tube S2 is connected to the sub-control circuit;

The resistor R1 is connected in parallel with the switch tube S2;

The sub-control circuit includes a first sampling terminal, a second sampling terminal, a first output terminal, and a second output terminal. The first sampling terminal samples the output voltage of the main circuit, and the second sampling terminal samples the For the voltage of the resistor R1, the first output terminal is connected to the main control circuit, and the second output terminal is connected to the switch S2;

When the sub-control circuit detects that the output voltage of the main circuit exceeds a third preset value, the control switch S2 is turned off; when it is detected that the voltage of the resistor R1 exceeds a fourth preset value, and the When the output voltage of the main circuit exceeds the third preset value, the output voltage of the main circuit is controlled to decrease by controlling the main control circuit, and the switch tube S2 is controlled to close.
The hot-swappable LED driving power supply according to claim 1, wherein the impedance of the resistor R1 is several or tens of times the impedance of the LED load.
The hot-swappable LED drive power supply according to claim 1, wherein the main control circuit includes a drive circuit, a photoelectric coupling circuit, and a voltage loop, and the input end of the voltage loop is connected to the main circuit. The output terminal of the voltage loop is connected to the input terminal of the drive circuit, and the output terminal of the drive circuit is connected to the switch tube S1 via the photoelectric coupling circuit.
The hot-swappable LED driving power supply according to claim 3, wherein the voltage loop includes an operational amplifier US1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C1 and a switch tube S3, The non-inverting input terminal of the operational amplifier US1 inputs the first voltage reference signal Vref1, one end of the resistor R3 is connected to the output positive terminal of the main circuit, and the other end of the resistor R3 is connected to one end of the resistor R4 , The other end of the resistor R4 is connected to the negative input end of the operational amplifier US1, the first end of the capacitor C1 and one end of the resistor R5, and the second end of the capacitor C1 is connected to one end of the resistor R2, The output end of the operational amplifier US1 is respectively connected to the other end of the resistor R2 and the input end of the driving circuit, the other end of the R5 is grounded, and the switch S3 is connected in parallel to the resistor R3. The control terminal is connected to the sub-control circuit as the control terminal of the main control circuit.
The hot-swappable LED driving power supply according to claim 3, wherein the voltage loop includes an operational amplifier US2, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a resistor R11, a capacitor C2 and the switch S4, one end of the resistor R7 is connected to the output end of the main circuit, and the other end of the resistor R7 is connected to the negative phase input end of the operational amplifier US2, the first end of the capacitor C2 and the resistor R8. One end is connected, the second end of the capacitor C2 is connected to one end of the resistor R6, the output end of the operational amplifier US2 is respectively connected to the other end of the resistor R6 and the input end of the driving circuit, and the other end of the resistor R8 Connected to ground; one end of the resistor R9 inputs the second voltage reference signal Vref2, the other end of the resistor R9 is connected to the non-inverting input end of the operational amplifier US2 as a common end, and the common end is connected to the resistor R10 Is connected to one end of the resistor R11, the other end of the resistor R11 is connected to ground, the other end of the resistor R10 is connected to one end of the switch tube S4, the other end of the switch tube S4 is connected to ground, and the switch The control end of the tube S4 is connected to the sub-control circuit.
The hot-swappable LED drive power supply according to claim 1, wherein the sub-control circuit includes a comparator US3, a comparator US4, an RS trigger A1, an RS trigger A2, and an RS trigger A3 , AND circuit AND, a first delay circuit and a second delay circuit, the positive phase input terminal of the comparator US3 is connected to the output terminal of the main circuit, and the negative phase input terminal of the comparator US3 inputs a third voltage For reference signal Vref3, the output terminal of the comparator US3 is connected to the S terminal of the RS flip-flop A1, and the Q terminal of the RS flip-flop A1 is respectively connected to the input terminal of the first delay circuit and the R terminal of the RS flip-flop A3, The output terminal of the first delay circuit is connected to the first input terminal of the AND circuit AND, the positive input terminal of the comparator US4 inputs the voltage sampling value of the resistor R1, and the negative input terminal of the comparator US4 inputs For the fourth voltage reference signal Vref4, the output terminal of the comparator US4 is connected to the second input terminal of the AND circuit AND, the output terminal of the AND circuit AND is connected to the S terminal of the RS flip-flop A2, and the RS trigger The Q terminal of the device A3 is respectively connected to the R terminal of the RS flip-flop A1, the R terminal of the RS flip-flop A2, and the control terminal of the switch S2, and the S terminal of the RS flip-flop A3 is connected to the output terminal of the second delay circuit, The Q terminal of the RS flip-flop A2 is respectively connected to the input terminal of the second delay circuit and the control terminal of the main control circuit.
A control method for a hot-swappable LED drive power supply, suitable for the hot-swappable LED drive power supply according to any one of claims 1 to 6, comprising the following steps:

S01: Sampling the output voltage of the main circuit;

S02: Sampling the voltage of the resistor R1;

S03: Determine whether the output voltage of the main circuit exceeds the third voltage reference signal Vref3, if the judgment is yes, go to step S04, if the judgment is no, then go back to step S03;

S04: Turn off the switch S2;

S05: Determine whether the voltage of the resistor R1 exceeds the fourth voltage reference signal Vref4, if the judgment is yes, go to step S06, if the judgment is no, then go back to step S03;

S06: Reduce the output voltage of the main circuit;

S07: Close the switch tube S2;

S08: Increase the output voltage of the main circuit to the rated value.
The control method of a hot-swappable LED drive power supply according to claim 7, characterized in that, in the step S08, the calculation formula of the rated value of the output voltage of the main circuit is:

Among them, V1 is the rated value of the output voltage of the main circuit.
The control method of a hot-swappable LED drive power supply according to claim 7, characterized in that, in the step S08, the calculation formula of the rated value of the output voltage of the main circuit is:

Among them, Z1 is the parallel resistance value of the resistor R10 and the resistor R11, V3 is the voltage value input by the non-inverting input terminal of the operational amplifier US2, and V1 is the rated output voltage of the main circuit.