CN213693452U

CN213693452U - MOS drive circuit and energy-saving module

Info

Publication number: CN213693452U
Application number: CN202022546938.7U
Authority: CN
Inventors: 郭李晔; 刘毅
Original assignee: Delixi Electric Co Ltd
Current assignee: Delixi Electric Co Ltd
Priority date: 2020-11-06
Filing date: 2020-11-06
Publication date: 2021-07-13
Anticipated expiration: 2030-11-06

Abstract

The utility model provides a MOS drive circuit and energy-conserving module belongs to low-voltage apparatus technical field, including the one-level switching circuit that is used for the rectangular wave voltage amplitude of rise that PWM provided, be used for making wave form keep forward second grade level switching circuit and push-pull drive circuit. The output end of the first level conversion circuit is connected with the input end of the second level conversion circuit, the output end of the second level conversion circuit is connected with the input end of the push-pull type driving circuit, and the output end of the push-pull type driving circuit is used as final output. The utility model discloses an adopt the di/dt that the independent circuit that comprises components and parts such as triode, resistance and diode reduces the wave form to simple structure and low cost effectively reduce the radio frequency range.

Description

MOS drive circuit and energy-saving module

Technical Field

The utility model relates to a low-voltage apparatus technical field especially relates to a MOS drive circuit of energy-conserving module of contactor and application thereof.

Background

At present, energy-saving modules in mainstream are realized by adopting a pulse width modulation method similar to a switching power supply in a centralized manner, the realization method mainly adopts a special chip, and voltage and current sampling and PWM output are integrally completed; and a scheme of adopting a general singlechip external amplification amplifier and an MOS driving chip is also adopted. The special driving chip has the advantages of strong driving capability, high speed, small volume, simple circuit and the like, but in the energy-saving module, the fact that great electromagnetic interference can be generated when attraction is maintained is found in the test process, the electromagnetic radio-frequency radiation is more than 50dB and exceeds 9.4.3.2 radio-frequency radiation emission test in national standard GB14048.4-2010 (test description, test method and test arrangement are shown in GB4824-2004)

The emission limits of electrical appliances are specified in the national standard:

1. when the environment is in the environment A,

measuring the distance at 30-230MHz, 40dB (uV/m) quasi peak value of 10 m;

the distance was measured at 230-1000MHz, 47dB (uV/m) quasi-peak 10 m.

Based on this, the present application is proposed.

Disclosure of Invention

The not enough to prior art, the utility model provides a MOS drive circuit for energy-conserving module optimizes energy-conserving module's EMC radio frequency radiation index performance, accords with national standard.

In order to achieve the above object, the utility model discloses MOS drive circuit structure for energy-saving module is as follows: the PWM driving circuit comprises a first-stage level conversion circuit for amplifying a rectangular wave voltage provided by PWM, a second-stage level conversion circuit for keeping a waveform in a forward direction and a push-pull driving circuit.

The PWM0 signal output by the processor is usually rectangular wave, the voltage amplitude is reversely amplified through the first level conversion circuit, the waveform polarity is consistent with the originally output rectangular wave signal through the reverse conversion of the second level conversion circuit, and finally a waveform with slower rising and falling is output through the push-pull type driving circuit, so that the di/dt of the waveform is reduced, and the effect of reducing the radio frequency radiation is further achieved.

The utility model discloses further set up as follows: the first-level conversion circuit comprises a triode Q1, a resistor R7, a resistor R8 and a diode D5, wherein the diode D5 is connected between the base electrode and the collector electrode of the triode Q1 in series; one end of the resistor R7 is connected with 12V high voltage, and the other end is connected to the collector of the triode Q1; one end of the resistor R8 is used for inputting PWM rectangular wave, the other end is connected to the base electrode of the triode Q1, the emitting electrode of the triode Q1 is grounded, the resistor R7 is larger than the resistor R8, the triode Q1 is in an amplification working state, and the triode Q1 is an NPN triode.

The utility model discloses further set up as follows: one end of the resistor R8, which is used for inputting the PWM rectangular wave, is provided with a pull-down resistor R9.

The utility model discloses further set up as follows: the two-stage level conversion circuit comprises a triode Q2, a resistor R6, a resistor R5 and a diode D4, wherein the diode D4 is connected between the base electrode and the collector electrode of the triode Q2 in series; one end of the resistor R6 is connected with the output end of the first level switching circuit, and the other end is connected to the base electrode of the triode Q2; the transistor Q2 has a collector connected in series with a resistor R5 and a high voltage of 12V, and an emitter connected to ground. The transistor Q2 is an NPN transistor.

The utility model also provides an energy-saving module, including coil, DC power supply input, with first MOS pipe, second MOS pipe, coil afterflow circuit, rectifier circuit and the filter circuit of coil series connection, the drain electrode of first MOS pipe is connected in the one end of coil, its source electrode is connected with the drain electrode electricity of second MOS pipe, its grid is driven by a drive circuit, the source electrode of second MOS pipe is through ground resistance R3 back ground connection, its grid by above-mentioned MOS drive circuit control.

The energy-saving module is further arranged as follows: the drive circuit of first MOS pipe includes secondary power supply and the resistance R1, diode D3, two-way TVS pipe and the electric capacity C that establish ties in proper order, and the both ends of two-way TVS pipe are connected to the grid and the source electrode of first MOS pipe respectively, RC integrator circuit is constituteed to resistance R1 and electric capacity C.

In order to accelerate the release speed of the contact mechanism of the contactor, the energy-saving module is further arranged as follows: and an RC discharge circuit is formed by connecting a resistor R2, a resistor R2 and a capacitor C in parallel between the source and the grid of the first MOS tube.

To ensure the current consumption speed of the RC discharge circuit, the energy saving module is further configured to: in the RC discharge circuit, the resistance value of the resistor R is not less than 10K, and the capacity of the capacitor C is less than 0.1 muF.

For convenience of use, the energy-saving module is further configured as follows: the coil freewheeling circuit is a diode D1 connected in parallel between one end of the coil and the source electrode of the first MOS tube, the cathode of the diode D1 is connected with one end of the coil, and the anode is connected with the source electrode of the first MOS tube.

The energy-saving module is further arranged as follows: the filter circuit consists of a differential mode inductor L1 and an X capacitor C1, and the capacitor C1 and the differential mode inductor L1 form the filter circuit with strong anti-interference performance and good filter effect

The utility model has the advantages as follows:

the utility model discloses an adopt independent one-level conversion circuit, second grade level conversion circuit and the push-pull drive circuit of constituteing by components and parts such as triode, resistance and diode, the MOS driver chip who replaces among the prior art is used for driving the second MOS pipe to improve the PWM waveform that acts on the grid of second MOS pipe, reduce the radio frequency radiation, when promoting product safety in utilization, also satisfied national standard.

Secondly, the utility model discloses the component mainly adopts triode, diode, resistance in the circuit, compares in MOS driver chip, the utility model discloses the cost of circuit is lower, circuit performance is better.

Drawings

Fig. 1 is a schematic diagram of a MOS driving circuit according to the prior art.

Fig. 2 is a schematic diagram of a MOS driving circuit according to an embodiment of the present invention.

Fig. 3 is a schematic circuit diagram of an energy-saving module according to an embodiment of the present invention.

Detailed Description

The utility model provides a MOS drive circuit and corresponding contactor for energy-conserving module, its one-level shift circuit 1 through setting up reverse amplified rectangular wave, be used for reverse second grade level shift circuit 2 and push-pull drive circuit 3 to strengthen current output, replaces the drive circuit who adopts MOS driver chip among the prior art, reduces the di/dt of wave form.

Embodiment 1 this embodiment provides a MOS driver circuit, which includes a first-stage level shifter circuit 1, a second-stage level shifter circuit 2, and a push-pull driver circuit 3, wherein an input terminal of the first-stage level shifter circuit 1 is configured to receive a PWM0 signal, that is, a 0-3V rectangular wave, an output terminal of the first-stage level shifter circuit 1 is connected to an input terminal of the second-stage level shifter circuit 2, an output terminal of the second-stage level shifter circuit 2 is connected to an input terminal of the push-pull driver circuit 3, and an output terminal of the push-pull driver circuit 3 is directly connected to a gate of a switching transistor (shown in the drawing as a MOS transistor T2) to be driven.

Referring to fig. 2, in the present embodiment, the first-stage level shifter 1 includes an NPN transistor Q1, a resistor R7, a resistor R8, and a diode D5, the diode D5 is connected in series between the base and the collector of the NPN transistor Q1 — the anode of the diode D5 is connected to the base of the NPN transistor Q1 and one end of the resistor R8, the cathode of the diode D5 is connected to the collector of the NPN transistor Q1, and the diode D5 is used to protect the transistor Q1. One end of the resistor R7 is connected to the 12V high voltage, and the other end is connected to the collector of the NPN transistor Q1. One end of the resistor R8 is used for inputting the PWM rectangular wave, the other end is connected to the base electrode of the NPN triode Q1, and the emitter electrode of the NPN triode Q1 is grounded. In this circuit, the collector of the NPN transistor Q1 outputs a waveform as an output terminal. In order to realize the amplification effect of the level shift circuit, the resistor R7 needs to be larger than the resistor R8, and the NPN transistor Q1 needs to be in an amplification operating state, in one example, the resistor R7 is 100K, and the resistor R8 is 10K, so that the current Ice is much smaller than the current Ib, and the purpose of controlling the operating state of the transistor Q1 is achieved.

With continued reference to fig. 2, in the present embodiment, the two-stage level shift circuit 2 includes an NPN transistor Q2, a resistor R6, a resistor R5, and a diode D4, wherein the diode D4 (wired in the same way as the diode D5) is connected in series between the base and the collector of the NPN transistor Q2. One end of the resistor R6 is used as the input end of the second-stage conversion circuit and is directly connected with the output end of the first-stage level conversion circuit 1, and the other end of the resistor R6 is connected to the base electrode of the NPN triode Q2. Meanwhile, the collector of the NPN triode Q2 is connected in series with the resistor R5 and then connected to a 12V high voltage, the emitter of the NPN triode Q2 is grounded, and the NPN triode Q2 is in a reverse conducting state. The collector of the NPN transistor Q2 serves as the output of the two-stage conversion circuit to output a waveform. In this embodiment, the resistance of the resistor R5 is 51K, the resistance of the resistor R6 is 10K, and the resistors R6 and R8 also have the function of stabilizing current.

The push-pull type driving circuit 3 is composed of an NPN triode Q3 and a PNP triode Q4, wherein bases of the NPN triode Q3 and the PNP triode Q4 are connected, and the bases of the NPN triode Q3 and the PNP triode Q4 are used as input ends and are connected with the collector output of the NPN triode Q2 in the second-stage conversion circuit. The collector of the NPN transistor Q3 is connected to the positive voltage of 12V, the emitter thereof is connected to the emitter of the PNP transistor Q4, and the collector of the PNP transistor Q4 is grounded. The output end of the push-pull driving circuit 3, namely the output end of the final MOS driving circuit, is led out from the connecting line between the emitter of the NPN triode Q3 and the emitter of the PNP triode Q4.

As can be seen from fig. 3, the 0-3V PWM rectangular wave signal passes through the first level conversion circuit 1 and then outputs a-12-0V rectangular wave circuit, and then passes through the second level conversion circuit and outputs a 0-12V rectangular wave circuit, and after passing through the push-pull driving circuit 3, the PWM rectangular wave signal finally outputs a triangular wave signal that rises slowly and falls slowly due to the switching speeds of the transistor Q3 and the transistor Q4. The di/dt of the rising edge and the falling edge of the triangular wave signal waveform is smaller than that of the rectangular wave.

Referring to fig. 1, in the prior art, a PWM0 signal input to TP3 is a horizontal, vertical, rectangular wave with amplitude of 0-3.3V, and after passing through a driver chip U3, a rectangular wave with the same polarity and level of 0-12V is output. The di/dt of the waveform is large, and needs to be improved by matching with other circuits or devices. Therefore, compared with the prior art, the embodiment realizes the existing drive circuit better than the MOS drive chip by a simple and low-cost independent circuit, and effectively improves the radio frequency condition of the MOS drive circuit.

In addition, a pull-down resistor R9 may be further disposed at one end of the resistor R8 for inputting the PWM rectangular wave, for maintaining the voltage at the PWM input in a stable low state.

Embodiment 2 this embodiment provides an energy saving module, as shown in fig. 3, including a coil L, a dc power input terminal, a MOS transistor T1 connected in series with the coil, a MOS transistor T2, a coil freewheeling circuit, a rectifying circuit, and a filtering circuit. The drain of the MOS transistor T1 is connected to one end of the coil L, the source thereof is electrically connected to the drain of the MOS transistor T2, the gate thereof is driven by a driving circuit, the source of the MOS transistor T2 is grounded through a grounding resistor R3, and the gate thereof is controlled by the MOS driving circuit in the embodiment. A line is led out from the input end DC + and the input end DC-and is connected to two input ends of a rectifier bridge DB1 after passing through a filter circuit formed by a differential mode inductor L1 and a capacitor C1, and a voltage dependent resistor RV1 can be further arranged between the two input ends of the rectifier bridge DB1 and is used for preventing lightning surge and improving the safety of the circuit. The positive output end of the rectifier bridge DB1 is connected with one connecting end JK1 of the coil, and the negative output end of the rectifier bridge DB1 is grounded.

Another connection end JK2 of the coil L is connected to the drain of the MOS transistor T1, the source of the MOS transistor T1 is connected to the drain of the MOS transistor T2, the gate of the MOS transistor T2 (main MOS transistor) is connected to the output end of the MOS driver circuit provided in embodiment 1, and the MOS driver circuit sends out the processed PWM control signal to control on/off of the MOS transistor T2. The source of the MOS transistor T2 is grounded via a grounding resistor R3. In addition, the junction JK1 is also connected to a power supply HV +, which also supplies power to the coil.

The coil freewheeling circuit adopts a diode D1, the cathode of the diode D1 is connected with the connecting end JK1 of the coil, and the anode is connected with the source electrode of the MOS transistor T1.

In order to drive the MOS transistor T1, the present embodiment is provided with a driving circuit, where the driving circuit includes a power supply HV +, and a resistor R1, a diode D3, and a bidirectional TVS tube ZD1 connected in series in this order, and two ends of the bidirectional TVS tube ZD1 are respectively connected to a gate and a source of the MOS transistor T1. In addition, a capacitor C3 and a resistor R2 are connected in parallel to both ends of the bidirectional TVS tube ZD1, that is, an RC discharge circuit formed by connecting the resistor R2 and the capacitor C3 in parallel is provided between the source and the gate of the first switching tube, and simultaneously, the resistor R1 and the capacitor C3 also form an RC integration circuit. The resistance of the resistor R2 is preferably not less than 10K, and the capacitance of the capacitor C3 is preferably less than 0.1 muF.

The current when the contactor is engaged is as follows: the current enters the rectifier bridge after passing through the filter capacitor from the power input end DC, then starts from the positive output end of the rectifier bridge DB1, flows through the coil of the contactor through the connecting end JK1, flows out of the coil through the connecting end JK2, then sequentially flows through the MOS tube T1 and D, S of the MOS tube T2, then passes through the diode D2, and completes one pull-in action through the contactor in the complete process.

When the MOS tube T2 is turned off, the freewheeling diode D1, the coil of the contactor and the MOS tube T1 form a conductive loop, and the driving circuit is powered by the auxiliary power supply HV +, so that the grid state is maintained, the T1 is in a conductive state, and the coil is continuously attracted.

If the contactor is required to be released, the power supply HV + is turned off, the MOS transistor T2 is turned off at the same time, and a certain current is remained in the coil during the turn-off process, and the residual current is continuously consumed through the resistor R2. Because the capacitor C3 has a small capacity and a small residual current, the residual current is quickly consumed in a circulation loop through the freewheeling diode D1, the coil and the MOS transistor T1, the MOS transistor T1 cannot be kept conductive, and the coil loses power to realize quick release of the contact mechanism.

Claims

1. A MOS drive circuit, characterized by: the PWM driving circuit comprises a primary level conversion circuit for amplifying a rectangular wave voltage provided by PWM, a secondary level conversion circuit for keeping a waveform in a forward direction and a push-pull driving circuit; the output end of the first level conversion circuit is connected with the input end of the second level conversion circuit, the output end of the second level conversion circuit is connected with the input end of the push-pull type driving circuit, and the output end of the push-pull type driving circuit is used as final output.

2. The MOS driver circuit of claim 1, wherein: the first-level conversion circuit comprises a triode Q1, a resistor R7, a resistor R8 and a diode D5, wherein the diode D5 is connected between the base electrode and the collector electrode of the triode Q1 in series; one end of the resistor R7 is connected with 12V high voltage, and the other end is connected to the collector of the triode Q1; one end of the resistor R8 is used for inputting PWM rectangular wave, the other end is also connected to the base electrode of the triode Q1, the emitter electrode of the triode Q1 is grounded, the resistor R7 is larger than the resistor R8, the triode Q1 is in an amplification working state, and the triode Q1 is an NPN triode.

3. The MOS driver circuit of claim 2, wherein: one end of the resistor R8, which is used for inputting the PWM rectangular wave, is provided with a pull-down resistor R9.

4. A MOS driver circuit as claimed in any one of claims 1 to 3, wherein: the two-stage level conversion circuit comprises a triode Q2, a resistor R6, a resistor R5 and a diode D4, wherein the diode D4 is connected between the base electrode and the collector electrode of the triode Q2 in series; one end of the resistor R6 is connected with the output end of the first level switching circuit, and the other end is connected to the base electrode of the triode Q2; the rear end of a collector series resistor R5 of the triode Q2 is connected with 12V high voltage, and an emitter of the triode Q2 is grounded; the transistor Q2 is an NPN transistor.

5. An energy saving module, characterized by: the direct current power supply comprises a coil, a direct current power supply input end, a first MOS tube, a second MOS tube, a coil follow current circuit, a rectifying circuit and a filter circuit, wherein the first MOS tube is connected with the coil in series, the drain electrode of the first MOS tube is connected with one end of the coil, the source electrode of the first MOS tube is electrically connected with the drain electrode of the second MOS tube, the grid electrode of the first MOS tube is driven by a driving circuit, the source electrode of the second MOS tube is grounded through a grounding resistor R3, and the grid electrode of the second MOS tube is controlled by the MOS driving circuit as claimed in any one.

6. The energy conservation module of claim 5, wherein: the drive circuit of first MOS pipe includes secondary power supply and the resistance R1, diode D3, two-way TVS pipe and the electric capacity C that establish ties in proper order, and the both ends of two-way TVS pipe are connected to the grid and the source electrode of first MOS pipe respectively, RC integrator circuit is constituteed to resistance R1 and electric capacity C.

7. The energy saving module of claim 5 or 6, wherein: a resistor R2 is connected between the source electrode and the grid electrode of the first MOS tube, and the resistor R2 and the capacitor C are connected in parallel to form an RC discharge circuit.

8. The energy conservation module of claim 7, wherein: in the RC discharge circuit, the resistance value of the resistor R is not less than 10K, and the capacity of the capacitor C is less than 0.1 muF.

9. The energy saving module of claim 5 or 6, wherein: the coil freewheeling circuit is a diode D1 connected in parallel between one end of the coil and the source electrode of the first MOS tube, the cathode of the diode D1 is connected with one end of the coil, and the anode is connected with the source electrode of the first MOS tube.

10. The energy saving module of claim 5 or 6, wherein: the filter circuit is composed of a differential mode inductor L1 and an X capacitor C1.