CN210351736U

CN210351736U - A drive circuit with low frequency flicker and high power factor

Info

Publication number: CN210351736U
Application number: CN201920786889.9U
Authority: CN
Inventors: 刘锦平; 林昱呈
Original assignee: Edison Opto Dongguan Co ltd
Current assignee: Edison Opto Dongguan Co ltd
Priority date: 2019-05-28
Filing date: 2019-05-28
Publication date: 2020-04-17
Anticipated expiration: 2029-05-28

Abstract

The utility model discloses a low-frequency flash high power factor drive circuit, which is characterized in that in the rising stage of the positive half period of alternating current, current flows through a first LED lamp bank, a first constant current module and a second constant current module and charges a charge-discharge module; the voltage continues to rise, the second LED lamp group is conducted, and the current flows through the first LED lamp group, the first constant current module, the second LED lamp group and the third constant current module to continue to charge the charging and discharging module; when the current is reduced to a level insufficient for maintaining the stable brightness of the first LED lamp group and the second LED lamp group in the descending stage of the positive half period of the alternating current, the charging and discharging module reversely discharges to provide stable current for the LED lamp groups until the next ascending period, and the periodic charging and discharging of the charging and discharging module ensures the stable power supply current of the LED lamp groups and reduces stroboflash; meanwhile, the drive circuit enables the waveform of the current to approach a sine wave, and the power factor of the circuit is improved.

Description

Low-frequency-flash high-power-factor driving circuit

Technical Field

The utility model relates to a LED drive power supply technical field especially relates to a drive circuit of low frequency sudden strain of a muscle high power factor.

Background

Because the LED lamp has the advantages of energy saving, high efficiency, environmental protection and long service life, the LED is used as a novel light source to gradually replace the traditional incandescent lamp and energy-saving lamp and is applied to various fields and places, the working condition of the LED lamp requires direct current, when the LED lamp is connected with a power supply system of alternating current, the alternating current needs to be converted into direct current, because the alternating current is sine wave, the direct current obtained after rectification still has pulsation, which can cause stroboflash of the LED, researches indicate that under an LED light source with stroboflash problem for a long time, visual fatigue and even eyesight injury can be generated, the current waveform can be adjusted by a constant current source in the prior art, the brightness of the LED lamp is kept stable, although the duty cycle can be adjusted to shorten the time period for the LED lamp to be alternately turned off, stroboscopic lighting still cannot be avoided, and the power factor is relatively low, therefore, an LED driving circuit with both low stroboflash and high power factor is a problem to be studied by those skilled in the art.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, the utility model provides a drive circuit which can effectively reduce the stroboflash of an LED lamp and has high power factor.

The utility model provides a technical scheme that its technical problem adopted is:

a low-flash high-power-factor driving circuit, comprising:

the LED lamp comprises a rectifying module, a first constant current module, a second constant current module, a third constant current module, a charging and discharging module, a first LED lamp group and a second LED lamp group; the first end of the rectification module is electrically connected with an external power supply and rectifies the alternating current into direct current; the first end of the first LED lamp group is electrically connected with the second end of the rectifying module and the first end of the charging and discharging module respectively, and the second end of the first LED lamp group is electrically connected with the first end of the first constant current module; the first end of the second LED lamp group is electrically connected with the second end of the first constant current module and the first end of the second constant current module, and the second end of the second LED lamp group is electrically connected with the first end of the third constant current module and the second end of the charge-discharge module; the second constant current module comprises a second constant current device and a second reference module used for being matched with the second constant current device to regulate current, the second constant current device comprises a second control end, a second input end and a second output end, the first end of the second reference module is electrically connected with the second control end and the second end of the third constant current module respectively, and the second end of the second reference module is electrically connected with the second output end and the ground; the second input end is electrically connected with the first end of the second LED lamp group.

The drive circuit with the low stroboscopic high power factor has the advantages that: alternating current of an external power supply is converted into direct current through a rectifying module of the circuit, and at the stage of rising of the positive half period of the alternating current voltage, the current is conducted and flows through the first LED lamp group, the first constant current module and the second constant current module, the charging and discharging module is charged, and the current output by the first end of the rectifying module continuously rises and reaches the limit value of the second constant current module to keep constant current; the voltage continuously rises, the second LED lamp group is conducted, current flows through the first LED lamp group, the first constant current module, the second LED lamp group, the third constant current module and the second reference module, the charging and discharging module is continuously charged, the current flowing into the second reference module from the second end of the third constant current module enables the voltage drop between the second control end and the second output end of the second galvanostat to reach a cut-off condition, the second galvanostat is cut off, the current output by the first end of the rectifying module continuously rises, the first constant current module limits the current flowing into the first LED lamp group and the second LED lamp group to reach a constant current, and the third constant current module limits the current output by the first end of the rectifying module to continuously rise and reach the constant current; when the current is reduced to be insufficient to maintain the first LED lamp group and the second LED lamp group to be stable in brightness in the descending stage of the positive half cycle of the alternating current, the charging and discharging module discharges reversely, the first constant current module limits the discharging speed and provides constant current for the first LED lamp group and the second LED lamp group, and the brightness of the first LED lamp group and the brightness of the second LED lamp group are kept unchanged until the next current ascending cycle; therefore, the driving circuit enables the waveform of the input current to change along the steps and approach to a sine wave, the power factor of the circuit is improved, meanwhile, the charge-discharge module is charged and discharged periodically, stable power supply currents of the first LED lamp group and the second LED lamp group are guaranteed, the brightness is stable, and stroboflash is reduced.

Further, the first constant current module comprises a first constant current device and a first reference module used for being matched with the first constant current device to regulate current, the first constant current device comprises a first control end, a first input end and a first output end, the first end of the first reference module is electrically connected with the first control end, the second end of the first reference module is respectively electrically connected with the first end and the first output end of the second LED lamp group, and the first input end is electrically connected with the second end of the first LED lamp group; the third constant current module comprises a third constant current device and a third reference module used for being matched with the third constant current device to adjust current, the third constant current device comprises a third control end, a third input end and a third output end, the first end of the third reference module is electrically connected with the third control end, and the second end of the third reference module is electrically connected with the third output end and the second control end respectively.

The LED lamp further comprises a current-limiting step slope circuit used for determining the slope of current rising, the first end of the current-limiting step slope circuit is electrically connected with the second end of the first constant current module and the first end of the second LED lamp group respectively, and the second end of the current-limiting step slope circuit is electrically connected with the first end of the second constant current module. The current-limiting step slope circuit enables the increasing slope to be closer to a sine wave when the current output by the first end of the rectifying module increases along steps, and the power factor of the circuit is improved.

Further, the current-limiting step slope circuit includes at least one resistor.

Further, the charging and discharging module comprises an energy storage unit, a charging branch and a discharging branch; the first end of the charging branch circuit is electrically connected with the first end of the discharging branch circuit and the first end of the first LED lamp set respectively, the second end of the charging branch circuit is electrically connected with the second end of the discharging branch circuit and the first end of the energy storage unit respectively, and the second end of the energy storage unit is electrically connected with the second end of the second LED lamp set.

Further, the energy storage unit comprises at least one capacitor.

Furthermore, the charge and discharge module further comprises a consumption circuit, and a first end of the consumption circuit is electrically connected with a first end of the charging branch circuit; the second end of the consumption circuit is electrically connected with the second end of the energy storage unit. When the power supply is turned off, the electric energy stored in the charge-discharge module flows out through the consumption circuit and is consumed rapidly, so that the situation that the stored electric energy flows through the first LED lamp group and the second LED lamp group and is extinguished slowly to affect use is avoided.

Further, the consumption circuit comprises at least one resistor.

Furthermore, the rectifier module further comprises a filter capacitor C1 for reducing current ripple, wherein a first end of the filter capacitor C1 is electrically connected with a second end of the rectifier module, and a second end of the filter capacitor C1 is grounded.

Drawings

The following figures are further illustrative of the present invention.

Fig. 1 is a schematic diagram of a low-frequency flash high power factor driving circuit according to the present invention.

Detailed Description

This section will describe in detail the embodiments of the present invention, preferred embodiments of the present invention are shown in the attached drawings, which are used to supplement the description of the text part of the specification with figures, so that one can intuitively and vividly understand each technical feature and the whole technical solution of the present invention, but they cannot be understood as the limitation of the protection scope of the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated with respect to the orientation description, such as up, down, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, a plurality of means are one or more, a plurality of means are two or more, and the terms greater than, less than, exceeding, etc. are understood as not including the number, and the terms greater than, less than, within, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless there is an explicit limitation, the words such as setting, installation, connection, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in combination with the specific contents of the technical solution.

Referring to fig. 1, a low-flash high power factor driving circuit includes: the LED lamp comprises a rectifying module 1, a first constant current module 3, a second constant current module 6, a third constant current module 7, a charging and discharging module 8, a first LED lamp group 2 and a second LED lamp group 4; the first end of the rectification module 1 is electrically connected with an external power supply and rectifies and outputs alternating current into direct current; the first end of the first LED lamp group 2 is electrically connected with the second end of the rectifier module 1 and the first end of the charge and discharge module 8 respectively, and the second end of the first LED lamp group 2 is electrically connected with the first end of the first constant current module 3; the first end of the second LED lamp group 4 is electrically connected to the second end of the first constant current module 3 and the first end of the second constant current module 6, and the second end of the second LED lamp group 4 is electrically connected to the first end of the third constant current module 7 and the second end of the charge and discharge module 8; the second constant current module 6 comprises a second constant current device 62 and a second reference module 61 for adjusting current in cooperation with the second constant current device 62, the second constant current device 62 comprises a second control end, a second input end and a second output end, the first end of the second reference module 61 is electrically connected with the second control end and the second end of the third constant current module 7 respectively, and the second end of the second reference module 61 is electrically connected with the second output end and ground; the second input end is electrically connected with the first end of the second LED lamp set 4. The first constant current module 3 comprises a first galvanostat 32 and a first reference module 31 used for matching with the first galvanostat 32 to adjust current, the first galvanostat 32 comprises a first control end, a first input end and a first output end, the first end of the first reference module 31 is electrically connected with the first control end, the second end of the first reference module 31 is respectively electrically connected with the first end and the first output end of the second LED lamp group 4, and the first input end is electrically connected with the second end of the first LED lamp group 2; the third constant current module 7 includes a third constant current device 72 and a third reference module 71 for matching with the third constant current device 72 to adjust current, the third constant current device 72 includes a third control end, a third input end and a third output end, a first end of the third reference module 71 is electrically connected to the third control end, and a second end of the third reference module 71 is electrically connected to the third output end and the second control end, respectively. The LED lamp further comprises a current-limiting step slope circuit 5, wherein the current-limiting step slope circuit is used for determining the slope when current jumps, the first end of the current-limiting step slope circuit 5 is electrically connected with the second end of the first constant current module 3 and the first end of the second LED lamp group 4 respectively, and the second end of the current-limiting step slope circuit 5 is electrically connected with the first end of the second constant current module 6. The current limiting step slope circuit 5 comprises at least one resistor. The charge-discharge module 8 comprises an energy storage unit 83, a charge branch 81 and a discharge branch 82; the first end of the charging branch 81 is electrically connected to the first end of the discharging branch 82 and the first end of the first LED lamp set 2, the second end of the charging branch 81 is electrically connected to the second end of the discharging branch 82 and the first end of the energy storage unit 83, and the second end of the energy storage unit 83 is electrically connected to the second end of the second LED lamp set 4. The energy storage unit 83 comprises at least one capacitor. The charge-discharge module 8 further includes a consumption circuit 84, and a first end of the consumption circuit 84 is electrically connected to a first end of the charging branch 81; a second terminal of the consumption circuit 84 is electrically connected to a second terminal of the energy storage unit 83. The rectifier module further comprises a filter capacitor C1 for reducing current ripple, wherein a first end of the filter capacitor C1 is electrically connected with a second end of the rectifier module 1, and a second end of the filter capacitor C1 is grounded.

Specifically, as shown in fig. 1, the first LED lamp group 2 includes one light emitting diode LED 1; it is understood that the first LED lamp group 2 may also include more than two light emitting diodes LEDs 1 connected in series. Similarly, as shown in fig. 1, the second LED lamp group 4 includes one LED2, it is understood that the second LED lamp group 4 may also include two or more LEDs 2 connected in series.

Specifically, as shown in fig. 1, the current-limiting step slope circuit 5 includes a resistor R7, and it is understood that the current-limiting step slope circuit 5 may also include more than two resistors connected in series.

Specifically, as shown in fig. 1, the energy storage unit 83 includes a capacitor C3, and it is understood that the energy storage unit 83 may also include two or more capacitors connected in parallel.

The alternating current of the external power source is converted into direct current through the rectifier module 1 of the circuit, specifically, in this embodiment, the rectifier module 1 is a full-wave rectifier bridge, a fuse RL and a voltage dependent resistor are arranged at the front end of the full-wave rectifier bridge for protecting a circuit, and at the positive half-cycle rising stage of the alternating current voltage, current is conducted and flows through the first LED lamp group 2, the first constant current module 3 and the second constant current module 6, and the charging module 8 is charged through the charging branch 81, specifically, a capacitor C3 is charged, as shown in fig. 1, the charging branch 81 includes resistors R8 and R9 connected in series, and it can be understood that the number of the resistors can be set in the charging branch 81 as required; the current output by the first end of the rectifying module 1 continuously rises and reaches the limit value of the second constant current module 6, and the constant current is kept; the voltage continues to rise, the second LED lamp group 4 is turned on, a current flows through the first LED lamp group 2, the first constant current module 3, the second LED lamp group 4, the third constant current module 6 and the second reference module 61, and continues to charge the charge-discharge module 8, a current flows into the second reference module 61 from the second end of the third constant current module 7, so that the voltage drop between the second control end and the second output end of the second galvanostat 62 reaches a cut-off condition, the second galvanostat 62 is turned off, the current output from the first end of the rectifying module 1 continues to rise, the first constant current module 3 limits the current flowing into the first LED lamp group 2 and the second LED lamp group 4 and reaches a constant current, and the third constant current module 7 limits the current output from the first end of the rectifying module 1 to continue to rise and reach a constant current; the first reference module (31), the second reference module (61), and the third reference module (71) are respectively used for correspondingly adjusting the constant current values of the first galvanostat (32), the second galvanostat (62), and the third galvanostat (72), as shown in fig. 1, the first reference module (31) is composed of resistors R1 and R2, it can be understood that the first reference module (31) can set the number of resistors as needed, and similarly, the second reference module (61) is composed of resistors R3 and R4, and the third reference module (71) is composed of resistors R5 and R6, which can both set the number of resistors as needed; in the descending stage of the positive half-cycle of the alternating current, when the current is reduced to be insufficient to maintain the first LED lamp group 2 and the second LED lamp group 4 to be stable in brightness, the energy storage unit (83) of the charge-discharge module 8 discharges in a reverse direction through the discharge path (82), specifically, the discharge path (82) is a diode D1, the first constant current module 3 limits the discharge speed and provides a constant current for the first LED lamp group 2 and the second LED lamp group 4, and the brightness of the first LED lamp group 2 and the second LED lamp group 4 is kept unchanged until the next current ascending period; when the external power supply is disconnected, the electric energy stored in the energy storage unit (83) is rapidly discharged through the consumption circuit (84), so that current is prevented from flowing through the first LED lamp group 2 and the second LED lamp group 4, and the brightness of the first LED lamp group 2 and the brightness of the second LED lamp group 4 are gradually extinguished and cannot be immediately extinguished, thereby affecting the use effect, specifically, the consumption circuit (84) includes at least one resistor, as shown in fig. 1, the consumption circuit (84) includes two resistors R10 and R11 connected in series, it can be understood that the consumption circuit (84) can set the number of resistors as required; the driving circuit is further provided with a second filter capacitor C2 for absorbing power grid surge and noise and protecting a circuit IC, the second filter capacitor C2 comprises a first end and a second end, and the first end of the second filter capacitor C2 is electrically connected with the second end of the consumption circuit (84) and the second end of the energy storage unit (83) respectively; therefore, the driving circuit enables the waveform of the input current to change along steps and approach to a sine wave, the power factor of the circuit is improved, and meanwhile, the charge and discharge module 8 charges and discharges periodically, so that the stable power supply current of the first LED lamp group 2 and the second LED lamp group 4 is ensured, the brightness is stable, and the stroboflash is reduced.

The above is only the preferred embodiment of the present invention, but the present invention is not limited to the above embodiments, and the technical effects of the present invention should fall into the protection scope of the present invention as long as it is reached by any of the same or similar means.

Claims

1. a drive circuit of low frequency flicker high power factor, is characterized in that, comprises: rectifier module (1), the first constant current module (3), the second constant current module (6), the third constant current module (7 ), a charging and discharging module (8), a first LED lamp group (2) and a second LED lamp group (4); the first end of the rectifier module (1) is electrically connected to the external power supply, and rectifies the alternating current to output is direct current; the first end of the first LED lamp group (2) is electrically connected to the second end of the rectifier module (1) and the first end of the charging and discharging module (8), respectively, and the first end of the The second end of the LED lamp group (2) is electrically connected to the first end of the first constant current module (3); the first end of the second LED lamp group (4) is connected to the first constant current The second end of the module (3) is electrically connected to the first end of the second constant current module (6), and the second end of the second LED lamp group (4) is electrically connected to the third constant current module ( The first end of 7) is electrically connected with the second end of the charging and discharging module (8); the second constant current module (6) includes a second constant current device (62) and is used to cooperate with the second constant current device (62). A second reference module (61) of a current regulator (62) for regulating current, the second current regulator (62) comprising a second control terminal, a second input terminal and a second output terminal, the second reference module ( The first end of 61) is electrically connected to the second control end and the second end of the third constant current module (7) respectively, and the second end of the second reference module (61) is respectively connected to the second end The output terminal is electrically connected to the ground; the second input terminal is electrically connected to the first terminal of the second LED lamp group (4).

2. The drive circuit of low frequency flicker and high power factor according to claim 1, wherein the first constant current module (3) comprises a first constant current device (32) and a A first reference module (31) for a current regulator (32) to adjust current, the first current regulator (32) includes a first control terminal, a first input terminal and a first output terminal, the first reference module The first end of (31) is electrically connected to the first control end, and the second end of the first reference module (31) is respectively connected to the first end and the first end of the second LED lamp group (4). The output terminal is electrically connected, the first input terminal is electrically connected to the second terminal of the first LED lamp group (2); the third constant current module (7) includes a third constant current device (72) and a third reference module (71) for adjusting current in cooperation with the third current constant device (72), the third current constant device (72) comprising a third control terminal, a third input terminal and a third output terminal , the first terminal of the third reference module (71) is electrically connected to the third control terminal, and the second terminal of the third reference module (71) is respectively connected to the third output terminal and the third control terminal. The two control terminals are electrically connected.

3. The drive circuit of low-frequency flicker and high power factor according to claim 1, further comprising a current-limiting step slope circuit (5) for determining the slope when the current jumps, the current-limiting step The first end of the jump slope circuit (5) is electrically connected to the second end of the first constant current module (3) and the first end of the second LED lamp group (4), respectively, and the current limiting step The second end of the jump slope circuit (5) is electrically connected to the first end of the second constant current module (6).

4 . The drive circuit with low frequency flicker and high power factor according to claim 3 , wherein the current limiting step slope circuit ( 5 ) comprises at least one resistor. 5 .

5. The drive circuit with low frequency flash and high power factor according to claim 1, wherein the charging and discharging module (8) comprises an energy storage unit (83), a charging branch (81) and a discharging branch circuit (82); the first end of the charging branch (81) is respectively electrically connected to the first end of the discharging branch (82) and the first end of the first LED lamp group (2), The second end of the charging branch (81) is respectively electrically connected with the second end of the discharging branch (82) and the first end of the energy storage unit (83), and the energy storage unit (83) ) is electrically connected to the second end of the second LED lamp group (4).

6 . The drive circuit with low frequency flicker and high power factor according to claim 5 , wherein the energy storage unit ( 83 ) comprises at least one capacitor. 7 .

7 . The drive circuit with low frequency flicker and high power factor according to claim 5 , wherein the charging and discharging module ( 8 ) further comprises a consumption circuit ( 84 ), and the first part of the consumption circuit ( 84 ) The terminal is electrically connected to the first terminal of the charging branch (81); the second terminal of the consumption circuit (84) is electrically connected to the second terminal of the energy storage unit (83).

8. The drive circuit with low frequency flicker and high power factor according to claim 7, wherein the consumption circuit (84) comprises at least one resistor.

9. The drive circuit of low-frequency flicker and high power factor according to any one of claims 1-8, characterized in that, further comprising a filter capacitor C1 for reducing current pulsation, and the first end of the filter capacitor C1 is connected to the filter capacitor C1. The second end of the rectifier module (1) is electrically connected, and the second end of the filter capacitor C1 is grounded.