CN117354998A

CN117354998A - Monopole PFC that can turn off completely removes stroboscopic circuit

Info

Publication number: CN117354998A
Application number: CN202210754078.7A
Authority: CN
Inventors: 张从峰; 潘泓
Original assignee: Shenzhen Bohua New Energy Technology Co ltd
Current assignee: Shenzhen Bohua New Energy Technology Co ltd
Priority date: 2022-06-28
Filing date: 2022-06-28
Publication date: 2024-01-05

Abstract

The invention discloses a monopole PFC stroboscopic removing circuit capable of being completely turned off, which comprises a PFC driving circuit based on LED non-isolation, wherein the PFC driving circuit comprises a L, N output end of an LED, an electronic switch Q1, a plurality of LED light source modules in a series structure, a parasitic capacitor C5 and a parasitic capacitor C6; the output end L, N of the LED and the ground wire form a loop through the electronic switch Q1, the parasitic capacitor C5 of the LED light source module and the parasitic capacitor C6, and the LED light source module also comprises a high-impedance switch end and a comparator U1B with standard voltage; when the output end of L, N outputs a dimming signal lower than 1V or gives an off signal externally, the voltage control signal of the comparator U1B is lower than the reference voltage, the comparator U1B outputs a low level, and the driving voltage of the high-impedance switch is pulled down, so that the loop between L, N and EARTH is completely disconnected, the LED light source module is completely turned off, and the unipolar PFC stroboscopic removing circuit can not only completely turn off non-isolated driving, but also solve the stroboscopic removing function.

Description

Monopole PFC that can turn off completely removes stroboscopic circuit

Technical Field

The invention relates to the technical field of LED non-isolation driving circuits, in particular to a monopole PFC stroboscopic removing circuit capable of being completely turned off.

Background

The non-isolated driving has been a development trend of industry at present because the non-isolated driving has gained increased attention in the LED driving and related application fields due to its excellent performance and ultra-high cost performance, but the non-isolated driving has been a problem that the LED panel still has a micro-bright condition under the condition of no input voltage or one turn-off of the L/N line because the parasitic capacitance of the input ac through the panel is small even if no voltage is input, because the micro voltage difference between the L/N line and the ground line causes the non-isolated power supply to be a micro-bright condition. Meanwhile, single-stage PFC generates the stroboscopic problem of the LED lamp beads because of the output 100HZ low frequency, and the application of the light is greatly limited.

Disclosure of Invention

The invention aims at the problems and provides a monopole PFC stroboscopic removing circuit which can be completely turned off, and the monopole PFC stroboscopic removing circuit not only can completely turn off non-isolated driving, but also can solve the stroboscopic removing function.

In order to achieve the technical purpose, the invention adopts a monopole PFC stroboscopic removing circuit capable of being completely turned off, which comprises a PFC driving circuit based on LED non-isolation, wherein the PFC driving circuit comprises a L, N output end of an LED, an electronic switch Q1, a plurality of LED light source modules in a series structure, a parasitic capacitor C5 and a parasitic capacitor C6; the output end L, N of the LED and the ground wire form a loop through the electronic switch Q1, the parasitic capacitor C5 of the LED light source module and the parasitic capacitor C6, and the LED light source module also comprises a high-impedance switch end and a comparator U1B with standard voltage; when the output end of L, N outputs a dimming signal lower than 1V or gives an off signal externally, the voltage control signal of the comparator U1B is lower than the reference voltage, the comparator U1B outputs a low level, and the driving voltage of the high-impedance switch is pulled down, so that the loop between L, N and EARTH is completely disconnected, and the LED light source module is completely turned off.

As a preferred aspect of the present invention, the high-impedance switch terminal is a high-impedance switch, and the high-impedance switch is composed of a diode D6, an electronic switch Q2, a diode D7, and an electronic switch Q3; when the electronic switch Q2 and the electronic switch Q3 are turned off, the driver outputs to the LED light source module to realize thorough high-impedance turn-off;

the L end of the LED output end is connected to the piezoresistor VDR1 through a fuse F1; the piezoresistor VDR1 and a piezoresistor VDR2 are connected to the gas discharge tube GT1 and input to the EARTH EARTH_IN, and the gas discharge tube GT1 and the resistor R1 are connected IN parallel; the capacitor also comprises a parasitic capacitor CX1, a capacitor C1 and a capacitor C2, wherein the parasitic capacitor CX1 is connected in parallel with the input end, and the capacitor C1 and the capacitor C2 are connected to the ground from the input end;

when the output end of the L, N output end L, N of the LED outputs a dimming signal lower than 1V or gives an off signal externally, the voltage control signal Vcontrol input by the 6-pin negative end of the comparator U1B is lower than the Vref reference voltage input by the 5-pin positive end, the 7-pin of the comparator U1B outputs a low level, and the driving voltages of the electronic switch Q2 and the electronic switch Q3 in the high-impedance switch are pulled down, so that a loop formed by L/N and the ground through the parasitic capacitor C5 or the parasitic capacitor C6 is thoroughly blocked, no fire is realized, and finally the LED light source module is completely turned off.

As a further preferred aspect of the present invention, the high impedance switch composed of the diode D6, the electronic switch Q2, the diode D7, and the electronic switch Q3 may be a relay, or an insulated gate bipolar transistor, or a thyristor, or a switching circuit composed of semiconductor devices.

As a further preferred aspect of the present invention, the LED-based non-isolated PFC driving circuit is a single-stage non-isolated driving circuit, or is a BOOST topology BOOST, or is a BUCK active power correction circuit.

As a further preferred aspect of the present invention, the electronic switches Q2 and Q3 may be operated in a switching state, or may be operated in a linear state by a control signal, so as to remove the 100HZ low frequency signal generated during PFC output to realize single-stage no strobe.

According to the circuit structure, the electronic switch Q2 and the stroboscopic electronic switch Q3 are added in the circuit, the voltage control signal Vcontrol input by the negative end of the U1B of the pin 6 of the comparator is lower than the Vref reference voltage input by the positive end of the pin 5 of the U1B, the pin 7 of the comparator outputs low level, the driving voltage of the electronic switch Q2 and the driving voltage of the electronic switch Q3 are pulled down, so that a loop between L, N and EARTH is completely disconnected, and finally the LED lamp beads are completely turned off.

Drawings

FIG. 1 is a circuit configuration diagram of a first embodiment of the present invention;

FIG. 2 is a circuit diagram of a second embodiment of the present invention;

Detailed Description

The invention is further described below with reference to the drawings and the detailed description.

Referring to fig. 1 and 2, a fully-cut-off monopole PFC stroboscopic removing circuit includes an LED-based non-isolated PFC driving circuit, which includes a L, N output end of an LED, an electronic switch Q1, a plurality of LED light source modules in a series structure, and a parasitic capacitor C5 and a parasitic capacitor C6.

In the functional module, the output end L, N of the LED and the ground wire form a loop through the electronic switch Q1, the parasitic capacitor C5 of the LED light source module and the parasitic capacitor C6, and the invention further comprises a high-impedance switch end and a comparator U1B with standard voltage; when the output end of L, N outputs a dimming signal lower than 1V or gives an off signal externally, the voltage control signal of the comparator U1B is lower than the reference voltage, the comparator U1B outputs a low level, and the driving voltage of the high-impedance switch is pulled down, so that the loop between L, N and EARTH is completely disconnected, and the LED light source module is completely turned off.

In the invention, a preferable high-impedance switch terminal is a high-impedance switch, and the high-impedance switch is composed of a diode D6, an electronic switch Q2, a diode D7 and an electronic switch Q3; when the electronic switch Q2 and the electronic switch Q3 are turned off, the driver outputs to the LED light source module to realize thorough high-impedance turn-off;

in the invention, the L end of the LED output end is connected to a piezoresistor VDR1 through a fuse F1; the piezoresistor VDR1 and a piezoresistor VDR2 are connected to the gas discharge tube GT1 and input to the EARTH EARTH_IN, and the gas discharge tube GT1 and the resistor R1 are connected IN parallel; meanwhile, the invention also comprises a parasitic capacitor CX1, a capacitor C1 and a capacitor C2, wherein the parasitic capacitor CX1 is connected in parallel with the input end, and the capacitor C1 and the capacitor C2 are connected to the ground from the input end;

In the present invention, the high impedance switch composed of the diode D6, the electronic switch Q2, the diode D7, and the electronic switch Q3 may be a relay, or an insulated gate bipolar transistor, or a thyristor, or a switching circuit composed of semiconductor devices.

In the invention, the preferred PFC driving circuit based on LED non-isolation is a single-stage non-isolation driving circuit, or is a BOOST topology BOOST or a BUCK BUCK active power correction circuit.

In the invention, the electronic switch Q2 and the electronic switch Q3 can work in a switching state or can work in a linear state through a control signal, so that a 100HZ low-frequency signal generated during PFC output is removed to realize single-stage no stroboscopic effect.

The foregoing is merely a preferred embodiment of the present invention, and it should be noted that it will be apparent to those skilled in the art that modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the scope of the invention.

Claims

1. A monopole PFC removes stroboscopic circuit that can turn off completely, including a PFC driving circuit based on LED non-isolation, this PFC driving circuit includes L, N output of an LED, electronic switch Q1, a plurality of LED light source modules of series connection structure, and parasitic capacitance C5, parasitic capacitance C6; the output end L, N of the LED and the ground wire form a loop through the electronic switch Q1, the parasitic capacitor C5 of the LED light source module and the parasitic capacitor C6, and the LED light source module is characterized by further comprising a high-impedance switch end and a comparator U1B with standard voltage; when the output end of L, N outputs a dimming signal lower than 1V or gives an off signal externally, the voltage control signal of the comparator U1B is lower than the reference voltage, the comparator U1B outputs a low level, and the driving voltage of the high-impedance switch is pulled down, so that the loop between L, N and EARTH is completely disconnected, and the LED light source module is completely turned off.

2. The fully-off unipolar PFC deflash circuit of claim 1, wherein the high impedance switch terminal is a high impedance switch comprising diode D6, electronic switch Q2, diode D7 and electronic switch Q3; when the electronic switch Q2 and the electronic switch Q3 are turned off, the driver outputs to the LED light source module to realize thorough high-impedance turn-off;

3. A fully-off unipolar PFC deflash circuit as in claim 2 wherein the high impedance switch comprising diode D6, electronic switch Q2, diode D7, and electronic switch Q3 is a relay, or is an insulated gate bipolar transistor, or is a thyristor, or is a switching circuit comprising semiconductor devices.

4. A fully shutdown, unipolar PFC deflash circuit as defined in claim 1 wherein the LED-based non-isolated PFC drive circuit is a single stage non-isolated drive, either BOOST topology BOOST, or BUCK active power correction circuit.

5. A fully shutdown, unipolar PFC deflash circuit as defined in claim 2 wherein the electronic switch Q2 and the electronic switch Q3 are operable in a switched state or in a linear state by a control signal to remove the 100HZ low frequency signal generated at the PFC output to achieve a single stage no strobe.