CN220440955U - Driving circuit and lamp - Google Patents

Abstract

The utility model provides a driving circuit and a lamp, wherein the driving circuit comprises: the rectification module is used for converting externally input alternating current into half-wave alternating current; the PFC module is used for boosting and adjusting the half-wave alternating current and outputting direct current of a first voltage, and is connected with the rectifying module; the BUCK module is used for reducing the direct current of the first voltage output by the PFC module and providing the direct current for a load, and the BUCK module is connected with the output end of the PFC module; the power supply module is used for supplying power to the BUCK module and the PFC module, the input end of the power supply module is connected with the output end of the rectifying module and is connected with the PFC module, and the output end of the power supply module is connected with the BUCK module and the PFC module. The PFC module and the BUCK module are powered by the power supply module, so that the power supply loss of the PFC module and the BUCK module is effectively reduced, the load operation with larger power can be driven while the small packaged chip is used, and the manufacturing cost is reduced.

Description

Driving circuit and lamp

Technical Field

The present disclosure relates to lighting devices, and particularly to a driving circuit and a lamp.

Background

Along with the improvement of living standard, the demands of people on illumination in different scenes are higher and higher, and the LED has the advantages of energy conservation, environmental protection, long service life, high light efficiency and the like, and is widely applied in the field of illumination. In the popularization and application process of the LED illumination, the LED lamp beads have higher requirements on the stability of current, so that corresponding driving circuits are required to be arranged for driving the LED lamp beads.

For this reason, various solutions have been proposed in the industry, and many LED driving schemes are also presented in LED lighting, where a high PF (Power Factor) non-isolated two-stage scheme is one of the commonly used line architectures, typically a front stage PFC (Power Factor Correction) architecture, and a back stage BUCK (BUCK) architecture.

In the BUCK architecture, more and more manufacturers integrate power MOS tubes into an IC chip from the cost, and the integrated power MOS scheme mainly comprises heating of an internal power supply circuit, a built-in MOS and a logic control circuit due to heating of the IC chip, so that a small-packaged IC (such as SOP8 or SOP 7) cannot drive a load with power of more than 30W. In the application of higher power, only the IC chip of the built-in MOS scheme, or the external heat dissipation measures can be replaced, so that the overall cost is increased.

In view of the foregoing, it is necessary to provide a driving circuit and a lamp, which reduce the manufacturing cost by adopting a BUCK architecture scheme with a MOS built in a small package.

Disclosure of Invention

The utility model aims to provide a driving circuit and a lamp capable of effectively controlling heating value.

In order to achieve the above object, the present utility model provides a driving circuit comprising:

the rectification module is used for converting the input alternating current into half-wave alternating current;

the PFC module is used for boosting and adjusting the half-wave alternating current and outputting direct current of a first voltage, and is connected with the rectifying module;

the BUCK module is used for reducing the direct current of the first voltage output by the PFC module and providing the direct current for a load, and the BUCK module is connected with the output end of the PFC module;

the power supply module is used for supplying power to the BUCK module and the PFC module, the input end of the power supply module is connected with the output end of the rectifying module and is connected with the PFC module, and the output end of the power supply module is connected with the BUCK module and the PFC module.

Optionally, the power supply module includes a voltage-multiplying rectifying circuit configured to supply power to the BUCK module and a linear voltage-stabilizing circuit configured to supply power to the PFC module.

Optionally, the voltage doubling rectifying circuit includes third electric capacity, fourth diode, second diode and third electrolytic capacitor, the third electric capacity is connected to the auxiliary winding in the PFC module, the positive pole of second diode with third electric capacity is connected, the negative pole of second diode with the positive pole of third electrolytic capacitor is connected, third electrolytic capacitor with BUCK chip of BUCK module is connected, the positive pole of fourth diode is grounded, the negative pole of fourth diode with third electric capacity is connected.

Optionally, the linear voltage stabilizing circuit includes a ninth resistor, a second triode, a first voltage stabilizing diode and a fifth capacitor, one end of the ninth resistor is connected with the positive electrode of the third electrolytic capacitor, the other end of the ninth resistor is connected with the base electrode of the second triode and the negative electrode of the first voltage stabilizing diode, and the emitter of the second triode is connected with the fifth capacitor.

Optionally, the power supply module further includes an eighth resistor and a fourth electrolytic capacitor, one end of the eighth resistor is connected with the output end of the rectifying module, the other end of the eighth resistor is connected with the positive electrode of the fourth electrolytic capacitor, meanwhile, the positive electrode of the fourth electrolytic capacitor is connected with the VCC pin of the PFC control chip of the PFC module, the eighth resistor is used for charging the fourth electrolytic capacitor, and the fourth electrolytic capacitor is used for outputting voltage to the PFC control chip.

Optionally, the power supply module includes a third diode, an anode of the third diode is connected with the fifth capacitor, and a cathode of the third diode is connected with a VCC pin of the PFC control chip.

Optionally, the PFC module includes an auxiliary winding, and the auxiliary winding is connected with an output end of the rectifying module to supply power to the driving circuit.

Optionally, the BUCK module includes a BUCK chip, the BUCK chip is high-voltage power supply for internal HV foot, HV foot of BUCK chip is connected with the output of power module.

Optionally, the step-down chip is provided with a built-in power MOS, and the BUCK module works in a BUCK topological structure.

Another object of the present utility model is to provide a lamp having the driving circuit.

In order to achieve the above object, the present utility model provides a lamp, including the driving circuit and a load, wherein the load is connected with the driving circuit.

Compared with the prior art, the technical scheme of the utility model has the following beneficial effects: according to the driving circuit, the PFC module and the BUCK module are powered through the power supply module, the power supply module takes power from the auxiliary winding of the PFC module and supplies the power to the PFC module and the BUCK module after processing, so that the power supply loss of the PFC module and the power supply loss of the BUCK module are reduced, heating is reduced, the PFC module and the BUCK module can drive a load with larger power to operate while using small packaged chips, the manufacturing cost is effectively reduced, and meanwhile, the circuit structure of the power supply module is designed to have a lightning protection function, so that the safety is good.

Drawings

FIG. 1 is a schematic block diagram of a driving circuit according to an embodiment of the present utility model;

fig. 2 is a circuit diagram of fig. 1.

100-a driving circuit;

10-rectifying circuit, 20-PFC module, 30-BUCK module, 40-power supply module.

Detailed Description

In order to make the objects, technical solutions and advantages of the present utility model more apparent, the present utility model will be described in detail with reference to the accompanying drawings and specific embodiments.

In this case, in order to avoid obscuring the present utility model due to unnecessary details, only the structures and/or processing steps closely related to the aspects of the present utility model are shown in the drawings, and other details not greatly related to the present utility model are omitted.

In addition, it should be further noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Referring to fig. 1-2, a driving circuit 100 according to a preferred embodiment of the utility model includes:

the rectification module 10 is connected with commercial power and is used for converting externally input alternating current into half-wave alternating current;

the PFC module 20 is connected with the rectifying module 10, and is used for boosting and adjusting the half-wave alternating current to output first voltage direct current;

the BUCK module 30 is connected with the output end of the PFC module 20, and is used for reducing and adjusting the first voltage direct current output by the PFC module 20 and then providing the first voltage direct current to a load;

the input end of the power supply module 40 is connected with the output end of the rectifying module 10 and the PFC module 20, and the output end of the power supply module 40 is connected with the BUCK module 30 and the PFC module 20 to supply power to the BUCK module 30 and the PFC module 20.

The heating of the BUCK module 30 mainly comprises the loss heating of the HV power supply part inside the BUCK chip U2 and the built-in power MOS and the loss heating of the logic control circuit in the BUCK module 30, wherein the loss of the built-in power MOS and the loss of the logic control circuit can not be changed after being shaped, the loss calculation formula of the HV power supply part of the BUCK chip U2 is p_loss= (Vin-v_cc) ×i_cc, wherein v_cc is the working voltage inside the BUCK chip U2, i_cc is the working current of the BUCK chip U2, vin is the input voltage of the HV pin of the BUCK chip U2, and it can be seen that the lower the input voltage of the HV pin of the BUCK chip U2 is, the lower the power supply loss of the BUCK chip U2 is.

Through the power supply module 40 that sets up, get the electricity from rectifying module 10 back, before PFC module 20 and provide BUCK module 30 and PFC module 20 again, compare in BUCK module 30 and directly get the electricity from the electrolytic capacitor after PFC module 20 steps up, can effectively reduce the input voltage of BUCK chip U2 of BUCK module 30, and then reduce BUCK chip U2's power loss, optimize the loss heating of BUCK module 30, the while also can reduce the consumption of PFC module 20, the whole consumption of better control drive circuit 100.

The power supply module 40 includes a voltage doubler rectifying circuit configured to supply power to the BUCK module 30 and a linear voltage stabilizing circuit configured to supply power to the PFC module 20. The voltage doubling rectifying circuit converts half-wave alternating current provided by the auxiliary winding T1 into direct current, and provides one part of the direct current for the BUCK chip U2 of the BUCK module 30, and the other part of the direct current flows into the linear voltage stabilizing circuit, and the linear voltage stabilizing circuit provides the direct current for the PFC control chip U1 after the direct current is depressurized.

The voltage doubling rectifying circuit comprises a third capacitor C3, a fourth diode D4, a second diode D2 and a third electrolytic capacitor EC3, wherein the third capacitor C3 is connected to an auxiliary winding T1 in the PFC module 20, the positive electrode of the second diode D2 is connected with the third capacitor C3, the negative electrode of the second diode D2 is connected with the positive electrode of the third electrolytic capacitor EC3, the third electrolytic capacitor EC3 is connected with a BUCK chip U2 of the BUCK module 30, the positive electrode of the fourth diode D4 is grounded, the negative electrode of the fourth diode D4 is connected with the third capacitor C3, and alternating current provided by the auxiliary winding T1 is converted into direct current through the voltage doubling rectifying circuit and then provided for the BUCK module 30.

The linear voltage stabilizing circuit comprises a ninth resistor R9, a second triode Q2, a first voltage stabilizing diode ZD1 and a fifth capacitor C5, one end of the ninth resistor R9 is connected with the positive electrode of the third electrolytic capacitor EC3, the other end of the ninth resistor R9 is connected with the base electrode of the second triode Q2 and the negative electrode of the first voltage stabilizing diode ZD1, and the emitter electrode of the second triode Q2 is connected with the fifth capacitor C5. And the direct current on the third electrolytic capacitor EC3 is subjected to voltage reduction treatment through a linear voltage stabilizing circuit and then is output to the PFC control chip U1, so that the power supply loss of the PFC control chip U1 is reduced and the PFC control chip U1 is kept in a working state.

The PFC module 20 includes an auxiliary winding T1, and the auxiliary winding T1 is connected to an output terminal of the rectifying module 10 to supply power to the driving circuit 100.

The power supply module 40 further comprises an eighth resistor R8 and a fourth electrolytic capacitor EC4, the power supply module 40 is connected with the output end of the rectifying module 10 through the eighth resistor R8, one end of the eighth resistor R8 is connected with the output end of the rectifying module 10, the other end of the eighth resistor R8 is connected with the positive electrode of the fourth electrolytic capacitor EC4, the positive electrode of the fourth electrolytic capacitor EC4 is connected with the VCC pin of the PFC control chip U1 of the PFC module 20, half-wave alternating current output by the rectifying module 10 charges the fourth electrolytic capacitor EC4 after passing through the eighth resistor R8, and when the voltage on the fourth electrolytic capacitor EC4 reaches the driving voltage of the PFC control chip U1, the PFC control chip U1 starts to work and outputs PWM signals. The eighth resistor R8 is used as a starting resistor, and charges the fourth electrolytic capacitor EC4 to start the PFC control chip U1.

The third electrolytic capacitor EC3 and the fourth electrolytic capacitor EC4 can adopt aluminum electrolytic capacitors with larger capacity, so that the lightning surge prevention capability of the driving circuit 100 is improved, and the overall safety of a circuit is improved.

The power supply module 40 includes a third diode D3, an anode of the third diode D3 is connected to the fifth capacitor C5, and a cathode of the third diode D3 is connected to the VCC pin of the PFC control chip U1. The third diode D3 has a reverse unidirectional conduction function, preventing the left circuit element of EC4 from affecting the charging of EC4 at the time of start-up.

The BUCK module 30 includes a BUCK chip U2, the BUCK chip U2 supplies power to the internal HV pin with high voltage, and the HV pin of the BUCK chip U2 is connected with the output end of the power supply module 40. The BUCK module 30 converts the high-voltage direct current on the first electrolytic capacitor EC1 into direct current with lower voltage on the second electrolytic capacitor EC2, the output ends led+ and LED-are respectively connected with the positive terminal and the negative terminal of the second electrolytic capacitor EC2, and the BUCK chip U2 is packaged by SOP8 and is widely used in designs below 30W.

The BUCK chip U2 is internally provided with a power MOS, the BUCK module 30 works in a BUCK topological structure, circuit devices are fewer, circuits are relatively simple, and meanwhile, higher conversion efficiency and lower electromagnetic interference are realized.

In some embodiments, the operating topology of the PFC module 20 is a BOOST architecture.

The output of the BUCK module 30 includes LED + and LED-for connection to a load to provide the voltage required for the load to operate.

The utility model also provides a lamp, which comprises the driving circuit 100 and a load, wherein the load is connected with the driving circuit, and the load with higher power is driven under the condition that the whole volume of the driving circuit 100 is smaller.

The operation flow of the driving circuit 100 is as follows:

when the input terminal L, N of the driving circuit 100 flows into the mains, the mains is converted into a high-voltage half-wave ac by the rectifying module 10. At this time, the high-voltage half-wave alternating current flows into the fourth electrolytic capacitor EC4 through the starting resistor, and when the voltage on the fourth electrolytic capacitor EC4 reaches the VCC starting voltage of the PFC control chip U1, the PFC control chip U1 starts to work to output the PWM signal, and the PFC module 20 works to raise the voltage on the first electrolytic capacitor to 400V. Since PFC module 20 operates in the PWM switching state, auxiliary winding T1 of the transformer is coupled to the PWM signal on the main winding, and the ZCD point of auxiliary winding T1 is in the PWM state of 40V. The voltage doubling rectifying circuit formed by the third capacitor C3, the fourth diode D4, the second diode D2 and the third electrolytic capacitor EC3 converts 40V PWM into 40V direct current to the third electrolytic capacitor EC3, the third electrolytic capacitor EC3 is connected to the HV pin of the BUCK chip U2, the voltage is larger than the minimum working voltage of the BUCK chip U2 by 30V at the moment, the BUCK chip U2 starts to work, and the circuit of the BUCK module 30 topology converts 400V direct current on the first electrolytic capacitor into direct current which can work by the LEDs. The 40V direct current on the third electrolytic capacitor EC3 is higher than the VCC maximum working voltage of the PFC control chip U1, the fourth electrolytic capacitor EC4 supplies power to the PFC control chip U1 through the VCC pin of the PFC control chip U1 after the ninth resistor R9, the second triode Q2, the first zener diode ZD1 and the fifth capacitor C5 are converted into the direct current of about 20V. The third diode D3 is anti-reverse-filling unidirectional conduction, so as to prevent the left circuit element of the fourth electrolytic capacitor EC4 from affecting the charging of the fourth electrolytic capacitor EC4 during starting.

The 40V direct current on the third electrolytic capacitor EC3 is directly supplied to the buck chip U2, the power supply loss of the buck chip U2 is p_loss= (Vin-v_cc) ×i_cc, vin is only 40V, and the voltage on the first electrolytic capacitor is 400V, compared with the direct power supply of the first electrolytic capacitor to the buck chip U2, the power supply loss is 1/10 of the original power supply loss.

Meanwhile, the linear voltage stabilizing circuit on the power supply module 40 supplies power to the PFC control chip U1, so that the loss of the PFC control chip U1 can be reduced, and the heating of the driving circuit 100 can be controlled better.

In summary, according to the driving circuit 100 of the present utility model, the power supply module 40 is configured to supply power to the PFC module 20 and the BUCK module 30, and the power supply module 40 takes power from the auxiliary winding T1 of the PFC module 20, so that compared with taking power directly from the boosted first electrolytic capacitor EC1, the power supply loss of the PFC module 20 and the BUCK module 30 is greatly reduced, the load operation with larger power can be driven while the small packaged chip is used, the manufacturing cost is effectively reduced, and meanwhile, the third electrolytic capacitor EC3 and the fourth electrolytic capacitor EC4 in the power supply module 40 can also prevent lightning surge, so that the safety is improved.

The above embodiments are only for illustrating the technical solution of the present utility model and not for limiting the same, and it should be understood by those skilled in the art that the technical solution of the present utility model may be modified or substituted without departing from the spirit and scope of the technical solution of the present utility model.

Claims (10)

1. A driving circuit, characterized by comprising:

a rectifying module (10) for converting an externally input alternating current into a half-wave alternating current;

the PFC module (20) is used for boosting and adjusting the half-wave alternating current and outputting direct current of a first voltage, and the PFC module (20) is connected with the rectifying module (10);

the BUCK module (30) is used for reducing the direct current of the first voltage output by the PFC module (20) and providing the direct current for a load, and the BUCK module (30) is connected with the output end of the PFC module (20);

the power supply module (40) is used for supplying power to the BUCK module (30) and the PFC module (20), the input end of the power supply module (40) is connected with the output end of the rectifying module (10) and is connected with the PFC module (20), and the output end of the power supply module (40) is connected with the BUCK module (30) and the PFC module (20).

2. The drive circuit of claim 1, wherein the power supply module (40) includes a voltage doubler rectifier circuit configured to power the BUCK module (30) and a linear regulator circuit configured to power the PFC module (20).

3. The driving circuit according to claim 2, wherein the voltage doubling rectifying circuit comprises a third capacitor (C3), a fourth diode (D4), a second diode (D2) and a third electrolytic capacitor (EC 3), the third capacitor (C3) is connected to an auxiliary winding (T1) in the PFC module (20), an anode of the second diode (D2) is connected to the third capacitor (C3), a cathode of the second diode (D2) is connected to an anode of the third electrolytic capacitor (EC 3), the third electrolytic capacitor (EC 3) is connected to a BUCK chip (U2) of the BUCK module (30), an anode of the fourth diode (D4) is grounded, and a cathode of the fourth diode (D4) is connected to the third capacitor (C3).

4. A driving circuit according to claim 3, characterized in that the linear voltage stabilizing circuit comprises a ninth resistor (R9), a second triode (Q2), a first zener diode (ZD 1) and a fifth capacitor (C5), one end of the ninth resistor (R9) is connected with the positive electrode of the third electrolytic capacitor (EC 3), the other end of the ninth resistor (R9) is connected with the base electrode of the second triode (Q2) and the negative electrode of the first zener diode (ZD 1), and the emitter electrode of the second triode (Q2) is connected with the fifth capacitor (C5).

5. The driving circuit according to any one of claims 1 to 4, wherein the power supply module (40) further includes an eighth resistor (R8) and a fourth electrolytic capacitor (EC 4), one end of the eighth resistor (R8) is connected to the output end of the rectifying module (10), the other end of the eighth resistor (R8) is connected to the positive electrode of the fourth electrolytic capacitor (EC 4), meanwhile, the positive electrode of the fourth electrolytic capacitor (EC 4) is connected to the VCC pin of the PFC control chip (U1) of the PFC module (20), the half-wave ac power output by the rectifying module (10) charges the fourth electrolytic capacitor (EC 4) after passing through the eighth resistor (R8), and when the voltage on the fourth electrolytic capacitor (EC 4) reaches the driving voltage of the PFC control chip (U1), the PFC control chip (U1) starts to operate and outputs a PWM signal.

6. The drive circuit according to claim 5, wherein the power supply module (40) further comprises a third diode (D3), the drive circuit further comprises a linear voltage stabilizing circuit, the linear voltage stabilizing circuit comprises a fifth capacitor (C5), an anode of the third diode (D3) is connected to the fifth capacitor (C5), and a cathode of the third diode (D3) is connected to a VCC pin of the PFC control chip (U1).

7. The drive circuit according to claim 1, characterized in that the PFC module (20) comprises an auxiliary winding (T1), the auxiliary winding (T1) being connected to the output of the rectifying module (10) for powering the drive circuit.

8. The drive circuit according to claim 1, characterized in that the BUCK module (30) comprises a BUCK chip (U2), the BUCK chip (U2) supplying internal HV pin high voltage, the HV pin of the BUCK chip (U2) being connected with the output of the power supply module (40).

9. The drive circuit according to claim 8, characterized in that the BUCK chip (U2) has a built-in power MOS, and the BUCK module (30) operates in a BUCK topology.

10. A lamp, characterized by comprising the driving circuit according to any one of claims 1-9 and a load, said load being connected to said driving circuit.