CN218472773U

CN218472773U - Anti-reverse connection circuit with under-voltage and over-voltage protection and soft start functions and motor controller

Info

Publication number: CN218472773U
Application number: CN202222527775.7U
Authority: CN
Inventors: 罗松
Original assignee: Dayang Electric Wuhan Research Institute Co ltd
Current assignee: Dayang Electric Wuhan Research Institute Co ltd
Priority date: 2022-09-23
Filing date: 2022-09-23
Publication date: 2023-02-10
Anticipated expiration: 2032-09-23

Abstract

The utility model discloses a take undervoltage overvoltage protection and soft start function prevent reverse connection circuit and motor controller, including preventing reverse connection circuit, power input Vi +, vi-form power output Vo +, vo-after preventing reverse connection circuit's processing, connect soft start circuit on load RL's power supply circuit, overvoltage protection circuit detects the voltage difference between power output Vo + and Vo-, when the voltage difference between power output Vo + and Vo-surpassed certain settlement voltage value U1, overvoltage protection circuit output signal triggered soft start circuit action, cut off load RL's power supply circuit; the undervoltage protection circuit detects the voltage difference between the power output Vo + and Vo-, when the voltage difference between the power output Vo + and Vo-is smaller than a certain set voltage value U2, the undervoltage protection circuit outputs a signal to trigger the soft start circuit to act, a power supply loop of a load RL is cut off, the impact current during power-on is reduced, the function is more complete, the overvoltage and undervoltage protection is realized on the hardware protection circuit, the protection is more timely, and the reliability is high.

Description

Anti-reverse connection circuit with under-voltage and over-voltage protection and soft start functions and motor controller

The technical field is as follows:

the utility model relates to a take under-voltage overvoltage protection and soft start function prevent reverse connection circuit and machine controller.

Background art:

in the application of a direct current circuit, a client utilizes a plug to connect a power supply, and if the power supply is reversely connected, the situation of short circuit of the circuit occurs, so that the circuit is burnt out, and the problem of reverse connection protection is considered when a product is designed. And introducing "reverse-connection protection" measures is generally undertaken from the point of view of structure and circuit design. The structure can adopt a fool-proof plug, the method is most intuitive, and the following explains a plurality of common anti-reverse connection circuits:

the simplest anti-reverse measure in the existing application is to use a fool-proof design on an interface, and the method can involve the die sinking cost brought by the structural change. The reverse connection prevention protection is carried out without changing the existing structure through electronic design, and the method is accepted by the public.

FIG. 1 is a most basic reverse-connection-proof electronic design, which utilizes the unidirectional conductivity of a diode for reverse-connection protection, when a power supply is reversely connected, the diode is reversely biased to be cut off, and no current flows through a power loop; when the power supply is connected positively, the diode can generate voltage drop, and extra power consumption can be generated on the diode, so that the circuit structure is suitable for low-power occasions; similarly, reverse connection protection can be achieved through the rectifier bridge, but power consumption is larger;

FIG. 2 is a diagram of a conventional reverse-connection protection circuit, which uses an NMOS body diode for reverse-connection protection; when the power supply is positively connected, the R1 provides VGS voltage of the MOS tube, the MOS tube is fully conducted, and the power supply normally supplies power to a load; when the power supply is reversely connected, the MOS tube body diode is reversely cut off, no current exists in a power loop, and the power consumption is very low; similarly, PMOS is also suitable for the circuit, and the circuit needs to be slightly adjusted;

fig. 3 is the improved circuit of fig. 2, which adds bus voltage sampling, sends the sampling signal to the microprocessor MCU for processing, and adopts software measures to complete under-voltage and over-voltage protection, and software protection has time delay, and if further product reliability is increased, a hardware protection circuit needs to be added.

The invention content is as follows:

the utility model aims at providing a take under-voltage overvoltage protection and soft start function prevent reverse circuit and machine controller that connects, can solve the anti-reverse circuit that connects of taking MOS pipe among the prior art, need increase the bus voltage sampling, give microprocessor MCU with bus voltage sampling signal and handle, adopt under-voltage and overvoltage protection that software measure was accomplished, software protection has the technical problem that time delay reliability reduces.

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

the anti-reverse connection circuit with the functions of under-voltage and overvoltage protection and soft start comprises an anti-reverse connection circuit, wherein power inputs Vi + and Vi-form power outputs Vo + and Vo-after being processed by the anti-reverse connection circuit, and the power outputs Vo + and Vo-supply power for a load RL, and is characterized in that: the overvoltage protection circuit detects the voltage difference between the power outputs Vo + and Vo-, and when the voltage difference between the power outputs Vo + and Vo-exceeds a certain set voltage value U1, the overvoltage protection circuit outputs a signal to trigger the soft start circuit to act, so that the power supply loop of the load RL is cut off; the undervoltage protection circuit detects a voltage difference between the power outputs Vo + and Vo-, and when the voltage difference between the power outputs Vo + and Vo-is smaller than a certain set voltage value U2, an output signal of the undervoltage protection circuit triggers the soft start circuit to act, so that a power supply loop of a load RL is cut off, wherein U1 is larger than U2.

The anti-reverse connection circuit comprises a resistor R5, a capacitor C2, a voltage stabilizing diode ZD4 and an MOS tube Q3, a voltage Vi + is connected to a G pole of the MOS tube Q3 through the resistor R5, a D pole of the MOS tube Q3 is connected with a power input Vi +, an S pole of the MOS tube Q3 is connected with the power input Vi-, the capacitor C2 is connected between the D pole of the MOS tube Q3 and the G pole of the MOS tube Q3, and two ends of the capacitor C2 are connected with the voltage stabilizing diode ZD4 in parallel.

Foretell soft start circuit includes MOS pipe Q4, electric capacity C1, zener diode DZ3 and resistance R4, connect MOS pipe Q4 between MOS pipe Q3 ' S the D utmost point and the power input Vi +, MOS pipe Q4 ' S the D utmost point of D utmost point electric connection MOS pipe Q3, MOS pipe Q4 ' S S utmost point electric connection power input Vi +, MOS pipe Q4 ' S G utmost point electric connection resistance R4 ' S one end, resistance R4 ' S the other end is as signal input end, parallelly connected zener diode DZ3 between MOS pipe Q4 ' S the D utmost point and MOS pipe Q4 ' S the G utmost point, zener diode DZ3 ' S both ends are still parallelly connected electric capacity C1.

The overvoltage protection circuit comprises a voltage stabilizing diode DZ1, a resistor R3, a resistor R5 and a triode Q2, wherein the voltage stabilizing diode DZ1, the resistor R3 and the resistor R5 are sequentially connected in series, and then two ends of the voltage stabilizing diode DZ1, the resistor R3 and the resistor R5 are respectively electrically connected with the power output Vo + and Vo-, the base electrode of the triode Q2 is electrically connected between the resistor R3 and the resistor R5, the emitting electrode of the triode Q2 is grounded, and the collecting electrode of the triode Q2 is connected with the signal input end of the resistor R4.

Foretell undervoltage protection circuit includes resistance R1, resistance R6, triode Q1, resistance R2 and zener diode DZ2, resistance R1's one end electricity is connected at power output Vo +, resistance R1's the other end is connected at triode Q1's projecting pole, triode Q1's collecting electrode electricity connecting resistance R6's one end, resistance R6's other end ground connection, triode Q1's base is connected to resistance R2 and zener diode DZ2 establish ties back one end, other end ground connection.

The utility model provides a motor controller, includes power supply circuit, microprocessor MCU and inverter circuit, power supply circuit including preventing reverse-connection protection circuit, its characterized in that: the reverse connection prevention protection circuit adopts the reverse connection prevention circuit with the functions of under-voltage and overvoltage protection and soft start.

Compared with the prior art, the utility model, following effect has:

1. soft start is completed by using the threshold voltage charging time of the MOS tube, so that the impact current during power-on is reduced, and the reliability is improved;

2. reverse connection protection and overvoltage and undervoltage protection are integrated, so that the function is more complete;

3. the overvoltage and undervoltage protection is realized on a hardware protection circuit, so that the reliability is improved compared with software protection; 4. other advantages of the present invention will be described in detail in the examples section.

Description of the drawings:

FIG. 1 is a schematic circuit diagram of a first prior art reverse-connect prevention circuit;

FIG. 2 is a schematic circuit diagram of a first prior art reverse-connect prevention circuit;

FIG. 3 is a schematic circuit diagram of a third prior art anti-reverse connection circuit;

fig. 4 is a block diagram of the circuit of the present invention;

FIG. 5 is a corresponding circuit diagram of FIG. 4;

fig. 6 is a circuit block diagram of a second embodiment of the present invention.

The specific implementation mode is as follows:

the present invention will be described in further detail with reference to the following detailed description of preferred embodiments and accompanying drawings.

The first embodiment is as follows:

as shown in fig. 4 and 5, the reverse connection preventing circuit with under-voltage and overvoltage protection and soft start function provided in this embodiment includes a reverse connection preventing circuit, wherein power inputs Vi +, vi-are processed by the reverse connection preventing circuit to form power outputs Vo +, vo-, and the power outputs Vo +, vo-supply the load RL, and is characterized in that: the overvoltage protection circuit detects the voltage difference between the power outputs Vo + and Vo-, and when the voltage difference between the power outputs Vo + and Vo-exceeds a certain set voltage value U1, the overvoltage protection circuit outputs a signal to trigger the soft start circuit to act, so that the power supply loop of the load RL is cut off; the undervoltage protection circuit detects a voltage difference between the power outputs Vo + and Vo-, and when the voltage difference between the power outputs Vo + and Vo-is smaller than a certain set voltage value U2, an output signal of the undervoltage protection circuit triggers the soft start circuit to act, so that a power supply loop of a load RL is cut off, wherein U1 is larger than U2. The set voltage values U1 and U2 are determined by hardware parameters.

The principle of the utility model is that:

1) According to the scheme, an overcurrent protection circuit with reverse connection prevention is provided, as shown in fig. 4 and 5, an MOS tube Q3 is used for reverse connection prevention, when a bus voltage U is in a normal range (namely U2 is more than U and less than U1), and when a positive electrode and a negative electrode of a power supply are correctly connected, the MOS tube Q4 and the MOS tube Q3 are disconnected, a triode Q1 in an undervoltage protection circuit is conducted, so that a resistor R4 of a soft start circuit has current flowing, the MOS tube Q4 is gradually conducted, a capacitor C1 is continuously charged to 15V and is clamped by a zener diode ZD3, the MOS tube Q4 is completely conducted, and then the MOS tube Q3 is also conducted, soft start is completed by using MOS tube threshold voltage charging time, impact current during power-on is reduced, and reliability is improved;

2) When the bus voltage U is greater than U1, the bus is in an overvoltage state, the voltage-stabilizing diode DZ1 is reversely broken down, the resistor R3 and the resistor R5 pass through current, so that the base of the triode Q2 obtains a starting signal, the triode Q2 is conducted, the potential of the collector of the triode Q2 is pulled down, the potential of the G electrode of the MOS tube Q4 is reduced, the MOS tube Q4 is switched off, and the power supply loop of the load RL is cut off.

3) When the bus voltage U is less than U2, the undervoltage state is achieved, the triode Q1 in the undervoltage protection circuit is closed, the capacitor C1 of the soft start circuit discharges through the resistor R4 and the resistor R6, the potential of the G pole of the MOS tube Q4 is reduced, the MOS tube Q4 is closed, and therefore the power supply loop of the load RL is cut off.

The starting time of the circuit can be controlled by adjusting the parameters of the resistor R5 and the capacitor C2 and the parameters of the resistor R4 and the capacitor C1, so that the function of soft start is achieved; when the input anode and the input cathode of the circuit are reversely connected, the whole circuit does not work because VGS voltage of the MOS tube cannot be established in a turn-off state.

The pins of the MOS transistor Q3 and the MOS transistor Q4 define: the G pole of the MOS tube refers to the grid electrode of the MOS tube; the S pole of the MOS tube is the source electrode of the MOS tube; the D pole of the MOS tube refers to the drain electrode of the MOS tube.

The pins of the transistor Q1 and the transistor Q2 define: emitter E, base B, collector C.

Example two:

as shown in fig. 6, the present embodiment is a motor controller, which includes a power supply circuit, a microprocessor MCU and an inverter circuit, where the power supply circuit includes an anti-reverse connection protection circuit, and is characterized in that: the reverse connection prevention protection circuit adopts the reverse connection prevention circuit with the functions of under-voltage and overvoltage protection and soft start in the embodiment I.

The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited thereto, and any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention are equivalent replacement modes, and are all included in the scope of the present invention.

Claims

1. The anti-reverse-connection circuit with the functions of under-voltage and over-voltage protection and soft start comprises an anti-reverse-connection circuit, wherein power inputs Vi + and Vi-form power outputs Vo + and Vo-after being processed by the anti-reverse-connection circuit, and the power outputs Vo + and Vo-supply power for a load RL, and is characterized in that: the overvoltage protection circuit detects the voltage difference between the power outputs Vo + and Vo-, and when the voltage difference between the power outputs Vo + and Vo-exceeds a certain set voltage value U1, the overvoltage protection circuit outputs a signal to trigger the soft start circuit to act, so that the power supply loop of the load RL is cut off; the undervoltage protection circuit detects a voltage difference between the power outputs Vo + and Vo-, and when the voltage difference between the power outputs Vo + and Vo-is smaller than a certain set voltage value U2, an output signal of the undervoltage protection circuit triggers the soft start circuit to act, so that a power supply loop of a load RL is cut off, wherein U1 is larger than U2.

2. The anti-reverse connection circuit with under-voltage and over-voltage protection and soft start functions of claim 1, characterized in that: the anti-reverse connection circuit comprises a resistor R5, a capacitor C2, a voltage stabilizing diode ZD4 and an MOS tube Q3, a voltage Vi + is connected to a G pole of the MOS tube Q3 through the resistor R5, a D pole of the MOS tube Q3 is electrically connected with a power input Vi +, an S pole of the MOS tube Q3 is electrically connected with the power input Vi-, the capacitor C2 is connected between the D pole of the MOS tube Q3 and the G pole of the MOS tube Q3, and two ends of the capacitor C2 are connected with the voltage stabilizing diode ZD4 in parallel.

3. The anti-reverse-connection circuit with under-voltage and over-voltage protection and soft start functions as claimed in claim 1 or 2, wherein: soft start circuit includes MOS pipe Q4, electric capacity C1, zener diode DZ3 and resistance R4, connect MOS pipe Q4 between MOS pipe Q3 ' S the D utmost point and the power input Vi +, MOS pipe Q4 ' S the D utmost point of D utmost point electric connection MOS pipe Q3, MOS pipe Q4 ' S S utmost point electric connection power input Vi +, MOS pipe Q4 ' S G utmost point electric connection resistance R4 ' S one end, resistance R4 ' S the other end is as signal input part, parallelly connected zener diode DZ3 between MOS pipe Q4 ' S the D utmost point and MOS pipe Q4 ' S the G utmost point, zener diode DZ3 ' S both ends are still parallelly connected electric capacity C1.

4. The anti-reverse-connection circuit with under-voltage and over-voltage protection and soft start functions as claimed in claim 3, wherein: the overvoltage protection circuit comprises a voltage stabilizing diode DZ1, a resistor R3, a resistor R5 and a triode Q2, wherein the voltage stabilizing diode DZ1, the resistor R3 and the resistor R5 are sequentially connected in series, and then two ends of the voltage stabilizing diode DZ1, the resistor R3 and the resistor R5 are respectively electrically connected with the power output Vo + and Vo-, the base electrode of the triode Q2 is electrically connected between the resistor R3 and the resistor R5, the emitting electrode of the triode Q2 is grounded, and the collecting electrode of the triode Q2 is connected with the signal input end of the resistor R4.

5. The anti-reverse connection circuit with under-voltage and over-voltage protection and soft start functions of claim 4, wherein: the undervoltage protection circuit includes resistance R1, resistance R6, triode Q1, resistance R2 and zener diode DZ2, resistance R1's one end electricity is connected at power output Vo +, resistance R1's the other end is connected at triode Q1's projecting pole, triode Q1's collecting electrode electricity connecting resistance R6's one end, resistance R6's other end ground connection, triode Q1's base is connected to resistance R2 and zener diode DZ2 establish ties back one end, other end ground connection.

6. The utility model provides a motor controller, includes power supply circuit, microprocessor MCU and inverter circuit, power supply circuit including preventing reverse-connection protection circuit, its characterized in that: the reverse connection prevention protection circuit adopts the reverse connection prevention circuit with the functions of under-voltage and overvoltage protection and soft start as claimed in any one of claims 1 to 5.