CN209930571U

CN209930571U - Anti-interference switching power supply circuit of LED lighting equipment

Info

Publication number: CN209930571U
Application number: CN201920457407.5U
Authority: CN
Inventors: 刘宇华; 桂庆良
Original assignee: Shenzhen Baolihong Electric Appliance Co Ltd
Current assignee: Shenzhen Baolihong Electric Appliance Co Ltd
Priority date: 2019-04-04
Filing date: 2019-04-04
Publication date: 2020-01-10
Anticipated expiration: 2029-04-04

Abstract

The utility model discloses a LED lighting apparatus's anti-interference switching power supply circuit, including main IC with all connect at main IC outlying EMI filter circuit, first rectification filter circuit, PFC circuit, voltage regulation circuit, LLC resonant circuit, output feedback circuit, EMI filter circuit, first rectification filter circuit, PFC circuit, voltage regulation circuit, LLC resonant circuit, output feedback circuit electricity in proper order are connected. The utility model discloses a second grade EMI filter circuit and the better high frequency transformer of electromagnetic shield nature have effectively reduced electromagnetic interference.

Description

Anti-interference switching power supply circuit of LED lighting equipment

Technical Field

The utility model relates to a, in particular to LED lighting apparatus's anti-interference switching power supply circuit.

Background

With the development of power electronic technology, the switching power supply module has started to replace the conventional rectifier power supply due to its advantages of small size, high efficiency, reliable operation, etc., and is widely applied to various fields of society. However, due to the high operating frequency of the switching power supply, fast current and voltage changes, i.e., dv/dt and di/dt, are generated inside the switching power supply, so that the switching power supply module will generate strong harmonic interference and spike interference, and affect the normal operation of its own circuit and other electronic systems through coupling paths such as conduction, radiation and crosstalk, and of course, itself will be affected by electromagnetic interference of other electronic devices. Since the country starts to enforce 3C certification on some electronic products, whether an electronic device can meet the electromagnetic compatibility standard or not will be related to whether the product can be sold on the market or not, so the electromagnetic compatibility of the switching power supply is very important.

SUMMERY OF THE UTILITY MODEL

Problem to prior art existence, the utility model provides a LED lighting apparatus's anti-interference switching power supply circuit.

In order to achieve the above purpose, the specific scheme of the utility model is as follows:

an anti-interference switch power supply circuit of an LED lighting device comprises a main IC, and an EMI filter circuit, a first rectification filter circuit, a PFC circuit, a voltage regulating circuit, an LLC resonant circuit and an output feedback circuit which are all connected to the periphery of the main IC, wherein the EMI filter circuit, the first rectification filter circuit, the PFC circuit, the voltage regulating circuit, the LLC resonant circuit and the output feedback circuit are sequentially and electrically connected.

Preferably, the circuit further comprises a protection circuit and a second rectifying and filtering circuit, the protection circuit is electrically connected with the EMI filtering circuit, and the second rectifying and filtering circuit is connected between the LLC resonant circuit and the output feedback circuit.

Preferably, the master IC employs TEA 1716.

Preferably, the EMI filter circuit employs dual stage EMI filtering.

Preferably, the first rectifying and filtering circuit adopts single-phase bridge rectification and CLC filtering.

Preferably, the inductor in the PFC circuit is a PFC inductor, and the PFC circuit is combined with the main IC to complete power factor correction of the circuit.

Preferably, the voltage regulating circuit comprises a capacitor C18 and resistors R12, R13, R14, R26 and R27 connected in series, one end of the capacitor C18 is connected between the resistors R26 and R14 and connected to the BOOST end of the main IC, and the other end is grounded together with the resistor R27.

Preferably, a transformer in the LLC resonant circuit is a high-frequency transformer EER4045, and the LLC resonant circuit is connected to the HBC module of the main IC.

Preferably, the output feedback circuit is connected to the FB terminal of the main IC through an optocoupler, and the other end of the output feedback circuit is connected to a current reference source.

Preferably, the second rectifying and filtering circuit adopts diode rectification and RC low-pass filtering, and a filter capacitor in the RC low-pass filtering adopts a point electrolytic capacitor.

Adopt the technical scheme of the utility model, following beneficial effect has:

(1) the EMI filter circuit adopts two-stage EMI filtering, so that electromagnetic interference is effectively filtered, and the performance of the switching power supply is improved;

(2) the LLC resonant circuit is combined with the HBC module of the main control chip, so that the frequency of the resonator is not changed greatly when the load and the input are changed greatly, zero voltage switching is realized in a full load range, and the power conversion loss of the circuit is smaller;

(3) the output feedback circuit inputs the feedback voltage to the FB pin of the main control chip through the optocoupler, so that the function of adjusting the resonant frequency can be realized;

(4) the high-frequency transformer in the LLC resonant circuit is made of an EER4045PC44 type magnetic core material with good electromagnetic shielding performance, and is further anti-interference;

(5) and the second rectifying and filtering circuit further filters noise.

Drawings

FIG. 1 is a block diagram of the present invention;

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

fig. 3 is a schematic diagram of the design of the high-frequency transformer T1 of the present invention.

The power supply comprises a 1-EMI filter circuit, a 2-first rectifying filter circuit, a 3-PFC circuit, a 4-voltage regulating circuit, a 5-LLC resonant circuit, a 6-output feedback circuit, a 7-protection circuit and an 8-second rectifying filter circuit

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1 to 2, the utility model provides a LED lighting apparatus's anti-interference switching power supply circuit, including main IC _ U1 with all connect at main IC _ U1 outlying EMI filter circuit 1, first rectification filter circuit 2, PFC circuit 3, voltage control circuit 4, LLC resonant circuit 5, output feedback circuit 6, EMI filter circuit 1, first rectification filter circuit 2, PFC circuit 3, voltage control circuit 4, LLC resonant circuit 5, output feedback circuit 6 electricity in proper order are connected.

The circuit further comprises a protection circuit 7 and a second rectifying and filtering circuit 8, wherein the protection circuit 7 is electrically connected with the EMI filtering circuit 1, and the second rectifying and filtering circuit 8 is connected between the LLC resonant circuit 5 and the output feedback circuit 6.

The master IC _ U1 employs TEA 1716.

The EMI filter circuit 1 adopts double-stage EMI filtering.

The first rectifying and filtering circuit 2 adopts single-phase bridge rectification and CLC filtering.

The inductor in the PFC circuit 3 is a PFC inductor, and the PFC circuit 3 is combined with the main IC _ U1 to complete power factor correction of the circuit.

The voltage regulating circuit 4 comprises a capacitor C18 and resistors R12, R13, R14, R26 and R27 which are connected in series, one end of the capacitor C18 is connected between the resistors R26 and R14 and connected to the BOOST end of the main IC _ U1, and the other end of the capacitor C18 is grounded together with the resistor R27.

The transformer in the LLC resonant circuit 5 adopts a high-frequency transformer EER4045, and the LLC resonant circuit 5 is connected to the HBC module of the main IC _ U1.

The output feedback circuit 6 is connected with the FB end of the main IC _ U1 through an optical coupler, and the other end of the output feedback circuit is connected with a current reference source.

The second rectifying and filtering circuit 8 adopts diode rectification and RC low-pass filtering, and a filtering capacitor in the RC low-pass filtering adopts a point electrolytic capacitor.

The utility model discloses a theory of operation does:

referring to fig. 1 to 2, after the voltage is filtered by the EMI filter circuit 1 to remove the electromagnetic interference, the first rectifying filter circuit 2 converts the alternating current into the direct current and filters the noise, and then the power factor is corrected by the PFC circuit 3, the voltage adjusting circuit 4 is responsible for detecting the input voltage and increasing the voltage by the voltage dividing resistor, then the zero voltage switching is realized by the LLC resonant circuit 5, and the noise is further rectified and filtered by the second rectifying filter circuit 8, and the output feedback circuit 6 is responsible for adjusting the resonant frequency.

The protection circuit 7 consists of a fuse, a temperature-sensitive resistor and a piezoresistor, plays a role in safety protection, and protects core devices from being damaged when a power supply is abnormal; the EMI filter circuit 1 filters electromagnetic interference and improves the performance of the switching power supply; the first rectifying and filtering circuit 2 filters noise by adopting single-phase bridge rectification and CLC filtering and converts alternating current into direct current; the PFC circuit 3 is combined with ZCD, OPFC and GSPFC pins of the main control chip to finish power factor correction of the circuit; the voltage regulating circuit 4 is combined with a BOOST pin of the main control chip, detects input voltage and improves the voltage through a divider resistor; the LLC resonant circuit 5 is combined with the HBC module of the main control chip, so that the frequency of the resonator does not change greatly when the load and input change is large, zero voltage switching is realized in a full load range, and the power conversion loss of the circuit is smaller; the second rectifying and filtering circuit 8 adopts diode rectification and RC low-pass filtering, and a filtering capacitor in the RC low-pass filtering adopts a point electrolytic capacitor to play roles of rectifying and filtering noise; the output feedback circuit 6 inputs the feedback voltage to the FB pin of the main control chip through the optical coupler, and the function of adjusting the resonant frequency can be realized.

Referring to fig. 3, when the high-frequency transformer T1 is designed, an EER4045PC44 type magnetic core material with good electromagnetic shielding performance is selected; c07 and C08 are turn-to-turn coupling circuits, C011 is inter-winding coupling capacitance, and when the transformer is wound, the distributed capacitance C011 is reduced as much as possible so as to reduce the coupling of high-frequency interference on the primary side of the transformer to the secondary side winding; in addition, in order to further reduce electromagnetic interference, a shielding layer is added between the primary winding and the secondary winding, and the shielding layer is well grounded, so that coupling capacitors C09 and C010 are formed between the primary winding and the secondary winding of the transformer and the shielding layer, and high-frequency interference current flows to the ground through the capacitors C09 and C010.

The above only is the preferred embodiment of the present invention, not so limiting the patent scope of the present invention, all of which are in the utility model discloses a conceive, utilize the equivalent structure transform that the content of the specification and the attached drawings did, or directly/indirectly use all to include in other relevant technical fields the protection scope of the present invention.

Claims

1. The anti-interference switch power supply circuit of the LED lighting equipment is characterized by comprising a main IC, and an EMI filter circuit, a first rectification filter circuit, a PFC circuit, a voltage regulating circuit, an LLC resonant circuit and an output feedback circuit which are all connected to the periphery of the main IC, wherein the EMI filter circuit, the first rectification filter circuit, the PFC circuit, the voltage regulating circuit, the LLC resonant circuit and the output feedback circuit are sequentially and electrically connected.

2. The antijam switching power supply circuit for LED lighting equipment as set forth in claim 1, further comprising a protection circuit electrically connected to the EMI filter circuit and a second rectifying filter circuit connected between the LLC resonant circuit and the output feedback circuit.

3. The tamper resistant switching power supply circuit for an LED luminaire of claim 1 or 2, wherein said primary IC employs TEA 1716.

4. The anti-jamming switching power supply circuit for an LED lighting device according to claim 3, wherein the EMI filter circuit employs dual stage EMI filtering.

5. The antijam switching power supply circuit for an LED lighting device as set forth in claim 3, wherein said first rectifying filter circuit employs single-phase bridge rectification and CLC filtering.

6. The anti-jamming switching power supply circuit of the LED lighting device according to claim 3, wherein the inductor in the PFC circuit is a PFC inductor, and the PFC circuit is combined with the main IC to complete power factor correction of the circuit.

7. The anti-jamming switching power supply circuit for LED lighting equipment according to claim 3, wherein the voltage regulating circuit comprises a capacitor C18 and resistors R12, R13, R14, R26 and R27 connected in series, one end of the capacitor C18 is connected between the resistors R26 and R14 and connected to the BOOST end of the main IC, and the other end is grounded together with the resistor R27.

8. The anti-jamming switching power supply circuit for the LED lighting device according to claim 3, wherein the transformer in the LLC resonant circuit is a high-frequency transformer EER4045, and the LLC resonant circuit is connected to the HBC module of the main IC.

9. The anti-jamming switching power supply circuit of an LED lighting device as claimed in claim 3, wherein the output feedback circuit is connected to the FB terminal of the main IC through an optical coupler, and the other end of the output feedback circuit is connected to a current reference source.

10. The antijamming switching power supply circuit for LED lighting equipment according to claim 2, wherein the second rectifying and filtering circuit employs diode rectification and RC low-pass filtering, and a filter capacitor in the RC low-pass filtering employs a point electrolytic capacitor.