CN217522737U

CN217522737U - Anti-interference circuit

Info

Publication number: CN217522737U
Application number: CN202221472768.5U
Authority: CN
Inventors: 曹佶; 蒋宇; 胡艳伟
Original assignee: Zhejiang Hangke Instrument Co ltd
Current assignee: Zhejiang Hangke Instrument Co ltd
Priority date: 2022-06-10
Filing date: 2022-06-10
Publication date: 2022-09-30
Anticipated expiration: 2032-06-10

Abstract

The utility model discloses an anti-interference circuit, which comprises a switch protection module, an EMI anti-interference module, a PFC module, a conversion module and a pi-shaped filtering module which are electrically connected in sequence; the PFC module comprises a rectifier bridge BD, an inductor L6, a controllable switch K2 and a diode D1, wherein the output end of the rectifier bridge BD is electrically connected with the input end of the inductor L6, the output end of the inductor L6 is respectively electrically connected with one end of the controllable switch K2 and the anode of the diode D1, the other end of the controllable switch K2 is electrically connected with the output end of the rectifier bridge BD, and the cathode of the diode D1 is electrically connected with the conversion module. The phase difference between the current and the voltage in the anti-interference circuit can be reduced.

Description

Anti-interference circuit

Technical Field

The utility model relates to an electronic circuit technical field especially relates to an anti-jamming circuit.

Background

In an electronic circuit, components such as a voltage transformer, an inductor, a capacitor and the like are often used, and all of the components can generate alternating current harmonics which can affect the circuit, and the harmonics even feed back to an input power supply to affect the whole circuit.

Therefore, the current circuit is usually provided with an anti-electromagnetic interference component, but the current anti-electromagnetic interference circuit uses a large amount of capacitance, so that the difference between current and voltage is large.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, the utility model aims to provide an anti-jamming circuit, it can reduce the phase difference of electric current and voltage in the anti-jamming circuit.

The purpose of the utility model is realized by adopting the following technical scheme:

an anti-jamming circuit, characterized by: the power supply comprises a switch protection module, an EMI anti-interference module, a PFC module, a conversion module and a pi-type filtering module which are electrically connected in sequence; the PFC module comprises a rectifier bridge BD, an inductor L6, a controllable switch K2 and a diode D1, wherein the output end of the rectifier bridge BD is electrically connected with the input end of the inductor L6, the output end of the inductor L6 is respectively electrically connected with one end of the controllable switch K2 and the anode of the diode D1, the other end of the controllable switch K2 is electrically connected with the output end of the rectifier bridge BD, and the cathode of the diode D1 is electrically connected with the conversion module.

Preferably, the EMI anti-interference module includes a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a common mode inductor L1, a common mode inductor L2, an inductor L3, and an inductor L4, an input end of the common mode inductor L1 is electrically connected to the capacitor C1, an output end of the common mode inductor L1 is electrically connected to the capacitor C2, an input end of the common mode inductor L2 is electrically connected to the capacitor C2, an output end of the common mode inductor L2 is electrically connected to the capacitor C3, the capacitor C3 is connected to the capacitor C4 in parallel, the inductor L3 is connected to the inductor L4 in parallel, two ends of the capacitor C3 are electrically connected to the inductor L3 and the inductor L4, and the capacitor C4 is electrically connected to the PFC module.

Preferably, the EMI immunity module further includes a capacitor C5, a capacitor C6, a capacitor C7, and a capacitor C8, the common mode inductor L1 is grounded through a capacitor C5 and a capacitor C7, respectively, and the common mode inductor L2 is grounded through a capacitor C6 and a capacitor C8, respectively.

Preferably, the switch protection module includes a switch K1 and a fuse F1 connected in series with the switch K1, and the fuse F1 is electrically connected to an input terminal of the common mode inductor L1.

Preferably, the conversion module is a DC/DC conversion module, the DC/DC conversion module includes a transformer P, a transistor T and a PWM control chip, a cathode of the diode D1 is electrically connected to an input end of a primary coil of the transformer P, an output end of the primary coil of the transformer P is electrically connected to a collector of the transistor T, a base of the transistor T is electrically connected to the PWM control chip, and an emitter of the transistor T is electrically connected to the pi-type filter module.

Preferably, the DC/DC conversion module further comprises a thermal sensor, a temperature probe of the thermal sensor is in contact with the transformer P, and the thermal sensor is in signal connection with the PWM control chip.

Preferably, the pi-type filter module includes an inductor L5, a capacitor C11, and a capacitor C12, one end of the inductor L5 is electrically connected to the capacitor C11, and the other end of the inductor L5 is electrically connected to the capacitor C12.

Preferably, the anti-jamming circuit further comprises a capacitor C10 and a capacitor C13, and the capacitor C10 and the capacitor C13 are respectively connected in parallel with the pi-type filtering module.

Preferably, a resistor R1 and a resistor R2 are electrically connected between the EMI interference rejection module and the PFC module, and the resistor R1 and the resistor R2 are connected in series and then connected in parallel with the PFC module.

Preferably, a capacitor C9 is electrically connected between the PFC module and the conversion module, and the capacitor C9 is respectively connected in parallel with the PFC module and the conversion module.

Compared with the prior art, the beneficial effects of the utility model reside in that:

the anti-interference circuit disclosed by the application is provided with the EMI anti-interference module and the pi-type filtering module, so that a lot of interference harmonic waves can be filtered, and the anti-interference performance of the circuit is enhanced;

meanwhile, a PFC module is arranged in the middle of the anti-interference circuit, is not provided with a filter capacitor and is purely resistive, so that the current waveform distortion and the phase difference with the voltage caused by the charging of the capacitor can be reduced, and the rectification can be performed through a rectifier bridge BD to filter out alternating current harmonic waves; the PFC module can also form a chopper circuit through the inductor L6, the controllable switch K2 and the diode D1, so that the power factor can be corrected.

Drawings

FIG. 1 is a block diagram of an anti-jamming circuit according to the present invention;

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

fig. 3 is a circuit structure diagram of the PFC module and the conversion module according to the present invention.

Detailed Description

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

as shown in fig. 1-3, the utility model discloses an anti-interference circuit, which comprises a switch protection module, an EMI anti-interference module, a PFC module, a conversion module and a pi-type filter module, which are electrically connected in sequence; the PFC module comprises a rectifier bridge BD, an inductor L6, a controllable switch K2 and a diode D1, wherein the output end of the rectifier bridge BD is electrically connected with the input end of the inductor L6, the output end of the inductor L6 is respectively electrically connected with one end of the controllable switch K2 and the anode of the diode D1, the other end of the controllable switch K2 is electrically connected with the output end of the rectifier bridge BD, and the cathode of the diode D1 is electrically connected with the conversion module.

The anti-interference circuit disclosed by the application is provided with the EMI anti-interference module and the pi-type filtering module, so that a lot of interference alternating current harmonic waves can be filtered, and the anti-interference performance of the circuit is enhanced; meanwhile, a PFC module is arranged in the middle of the anti-interference circuit, is not provided with a filter capacitor and is purely resistive, so that the current waveform distortion and the phase difference with the voltage caused by the charging of the capacitor can be reduced, and the AC harmonic can be filtered out by rectifying through a rectifier bridge BD; the PFC module can also realize the correction of power factors through a chopper circuit consisting of the inductor L6, the controllable switch K2 and the diode D1.

The switch protection module comprises a switch K1 and a fuse F1 connected with the switch K1 in series, wherein the fuse F1 is electrically connected with an input end of the common mode inductor L1. The fuse F1 plays the effect of overcurrent protection, switch K1 plays the effect of start-stop, switch K1 can carry out electric connection with the commercial power. The conversion module can be a conversion module for electrical conversion of electrical frequency, voltage or current type and the like. A capacitor C9 is electrically connected between the PFC module and the conversion module, the capacitor C9 is respectively connected in parallel with the PFC module and the conversion module, and the capacitor C9 is a thin film capacitor for anti-electromagnetic interference.

As shown in fig. 2, in a preferred embodiment, the EMI immunity module includes a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, a capacitor C6, a capacitor C7, a capacitor C8, a common mode inductor L1, a common mode inductor L2, an inductor L3, and an inductor L4, an input end of the common mode inductor L1 is electrically connected to the capacitor C1, an output end of the common mode inductor L1 is electrically connected to the capacitor C2, an input end of the common mode inductor L2 is electrically connected to the capacitor C2, an output end of the common mode inductor L2 is electrically connected to the capacitor C3, the capacitor C3 is connected to the capacitor C4 in parallel, the inductor L3 is connected to the inductor L4 in parallel, two ends of the capacitor C3 are respectively electrically connected to the inductor L3 and the inductor L4, and the capacitor C4 is electrically connected to the PFC module. The common mode inductor L1 is grounded through a capacitor C5 and a capacitor C7, respectively, and the common mode inductor L2 is grounded through a capacitor C6 and a capacitor C8, respectively.

In the above embodiment, the capacitor C1, the capacitor C5, and the capacitor C7 respectively form an LC filtering module with the common-mode inductor L1, so that common-mode and differential-mode filtering is realized, an interference signal introduced by an input power supply can be blocked from entering a post-stage circuit, and an interference signal generated by the post-stage circuit is filtered out, so that the interference signal is prevented from being fed back to the input power supply to affect other devices. Similarly, the capacitor C2, the capacitor C6, and the capacitor C8 form an LC filter module with the common mode inductor L2, respectively, so as to achieve the effect of two-stage common mode inductor filtering. In addition, the capacitors C3 and C4 and the inductor L3 and the inductor L4 form an LC filter circuit, respectively, so as to further filter ac harmonics.

The EMI anti-interference module and the PFC module are electrically connected with a resistor R1 and a resistor R2, and the resistor R1 and the resistor R2 are connected in series and then connected with the PFC module in parallel. Because the EMI anti-interference module is provided with a plurality of inductors, when the anti-interference circuit is disconnected, the current induced by the inductors in the EMI anti-interference module can be absorbed by the resistor R1 and the resistor R2, so that the circuit is prevented from being burnt out.

In a preferred embodiment, as shown in fig. 3, the conversion module is a DC/DC conversion module, the DC/DC conversion module includes a transformer P, a transistor T, a thermal sensor and a PWM control chip, a cathode of the diode D1 is electrically connected to an input terminal of the transformer P primary coil, an output terminal of the transformer P primary coil is electrically connected to a collector of the transistor T, a base of the transistor T is electrically connected to the PWM control chip, and an emitter of the transistor T is electrically connected to the pi filter module. And a temperature probe of the thermal sensor is in contact with the transformer P, and the thermal sensor is in signal connection with the PWM control chip.

In the above embodiment, the transistor T controls the transformer P to operate (transform) by receiving the pulse signal sent by the PWM control chip, when the transformer is overheated, the thermal sensor transmits a thermal signal to the PWM control chip, the PWM control chip outputs a pulse signal with a small duty ratio to the transistor T, and the transistor T reduces the voltage or operating frequency output by the transformer P, so that the transformer P is not heated any more, and temperature control is achieved.

In a preferred embodiment, as shown in fig. 2, the anti-jamming circuit further includes a capacitor C10 and a capacitor C13, and the capacitor C10 and the capacitor C13 are respectively connected in parallel with the pi filter module. The pi-type filter module comprises an inductor L5, a capacitor C11 and a capacitor C12, wherein one end of the inductor L5 is electrically connected with the capacitor C11, and the other end of the inductor L5 is electrically connected with the capacitor C12.

In the above embodiment, the input and output of the pi filter module are low impedance, and the insertion loss characteristics are better than those of the RC filter module and the LC filter module. The capacitor C10 and the capacitor C13 can enhance the filtering capability of the circuit.

In summary, the anti-interference circuit is provided with an EMI anti-interference module, a PFC module and a pi-type filtering module, so that a plurality of harmonic waves can be filtered out, and the anti-interference capability is enhanced. The PFC module is not provided with a capacitor and is purely resistive, so that the current waveform distortion and the phase difference with the voltage caused by the charging of the capacitor can be weakened, and the correction of power factors can be realized through a chopper circuit consisting of the inductor L6, the controllable switch K2 and the diode D1, so that the anti-interference performance of the circuit is stronger.

Various other modifications and changes may be made by those skilled in the art based on the above-described technical solutions and concepts, and all such modifications and changes are intended to fall within the scope of the claims.

Claims

1. An anti-jamming circuit, characterized by: the power supply comprises a switch protection module, an EMI anti-interference module, a PFC module, a conversion module and a pi-type filtering module which are electrically connected in sequence; the PFC module comprises a rectifier bridge BD, an inductor L6, a controllable switch K2 and a diode D1, wherein the output end of the rectifier bridge BD is electrically connected with the input end of the inductor L6, the output end of the inductor L6 is respectively electrically connected with one end of the controllable switch K2 and the anode of the diode D1, the other end of the controllable switch K2 is electrically connected with the output end of the rectifier bridge BD, and the cathode of the diode D1 is electrically connected with the conversion module.

2. The immunity circuit of claim 1, wherein: the EMI anti-interference module comprises a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, a common mode inductor L1, a common mode inductor L2, an inductor L3 and an inductor L4, wherein an input end of the common mode inductor L1 is electrically connected with the capacitor C1, an output end of the common mode inductor L1 is electrically connected with the capacitor C2, an input end of the common mode inductor L2 is electrically connected with the capacitor C2, an output end of the common mode inductor L2 is electrically connected with the capacitor C3, the capacitor C3 is connected with the capacitor C4 in parallel, the inductor L3 is connected with the inductor L4 in parallel, two ends of the capacitor C3 are respectively electrically connected with the inductor L3 and the inductor L4, and the capacitor C4 is electrically connected with the PFC module.

3. The immunity circuit of claim 2, wherein: the EMI anti-interference module further comprises a capacitor C5, a capacitor C6, a capacitor C7 and a capacitor C8, the common mode inductor L1 is grounded through a capacitor C5 and a capacitor C7 respectively, and the common mode inductor L2 is grounded through a capacitor C6 and a capacitor C8 respectively.

4. The immunity circuit of claim 3, wherein: the switch protection module comprises a switch K1 and a fuse F1 connected in series with the switch K1, wherein the fuse F1 is electrically connected with the input end of the common mode inductor L1.

5. The immunity circuit of claim 1, wherein: the conversion module is a DC/DC conversion module, the DC/DC conversion module comprises a transformer P, a triode T and a PWM control chip, the cathode of the diode D1 is electrically connected with the input end of the primary coil of the transformer P, the output end of the primary coil of the transformer P is electrically connected with the collector of the triode T, the base of the triode T is electrically connected with the PWM control chip, and the emitter of the triode T is electrically connected with the pi-type filtering module.

6. The immunity circuit of claim 5, wherein: the DC/DC conversion module further comprises a thermal sensor, a temperature probe of the thermal sensor is in contact with the transformer P, and the thermal sensor is in signal connection with the PWM control chip.

7. The immunity circuit of claim 1, wherein: the pi-type filter module comprises an inductor L5, a capacitor C11 and a capacitor C12, wherein one end of the inductor L5 is electrically connected with the capacitor C11, and the other end of the inductor L5 is electrically connected with the capacitor C12.

8. The immunity circuit of claim 7, wherein: the anti-jamming circuit further comprises a capacitor C10 and a capacitor C13, and the capacitor C10 and the capacitor C13 are connected with the pi-type filtering module in parallel respectively.

9. The immunity circuit of claim 1, wherein: a resistor R1 and a resistor R2 are electrically connected between the EMI anti-interference module and the PFC module, and the resistor R1 is connected in series with the resistor R2 and then connected in parallel with the PFC module.

10. The immunity circuit of claim 1, wherein: a capacitor C9 is electrically connected between the PFC module and the conversion module, and the capacitor C9 is respectively connected in parallel with the PFC module and the conversion module.