CN214479558U

CN214479558U - Undervoltage release

Info

Publication number: CN214479558U
Application number: CN202120117367.7U
Authority: CN
Inventors: 蔡友锋; 王帮乐; 孙肇钊
Original assignee: Zhejiang Chint Electrics Co Ltd
Current assignee: Zhejiang Chint Electrics Co Ltd
Priority date: 2021-01-15
Filing date: 2021-01-15
Publication date: 2021-10-22
Anticipated expiration: 2031-01-15

Abstract

An under-voltage release comprises a power circuit, an under-voltage comparison circuit, a drive circuit and a release coil which are connected in sequence, and a rectifying circuit respectively connected with the power circuit, the undervoltage comparison circuit, the drive circuit and the trip coil, wherein the rectifying circuit respectively supplies power to the power circuit, the drive circuit and the trip coil, the power circuit supplies power to the undervoltage comparison circuit, the drive circuit comprises an MOS tube Q3 connected with the trip coil in series, and a PWM signal generator connected with the control end of the MOS tube Q3, an under-voltage comparison circuit collects the voltage signal of the rectification circuit, and the PWM signal generator is driven to output a high level signal and a PWM duty ratio signal in sequence according to the voltage signal of the rectifying circuit, the MOS tube Q3 is controlled to be switched on to supply power for the trip coil, the PWM duty ratio signal does not need to be generated by a single chip microcomputer, the step of programming the single chip microcomputer is omitted, and the PWM duty ratio signal directly output by the WM signal generator U2 is more stable.

Description

Undervoltage release

Technical Field

The utility model relates to a low-voltage apparatus field especially relates to an undervoltage release.

Background

The under-voltage release is often used for the circuit breaker to carry out under-voltage protection, and the under-voltage release comprises coil, iron core and spring usually, need attract iron core compression spring through the heavy current when the coil is gone up the electricity, and the coil also needs to continuously attract the iron core after going up the electricity, guarantees that the spring is compressed always, stops when appearing under-voltage for the coil power supply, makes the spring release can and drive the iron core and drive the circuit breaker tripping operation.

In order to solve the problem of heating of the coil caused by continuous attraction of the iron core, although the current passing through the coil can be reduced through the PWM duty ratio signal, in the prior art, most of the PWM duty ratio signals are generated through a single chip microcomputer, the single chip microcomputer is required to be programmed, an intermediate PWM driving chip is also required, and the structure of a driving circuit is very complex.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome prior art's defect, provide an energy-concerving and environment-protective and low under-voltage release that generates heat.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model provides an undervoltage release, it is including the power supply circuit who connects gradually, undervoltage comparison circuit, drive circuit and trip coil, and respectively with power supply circuit, undervoltage comparison circuit, the rectifier circuit that drive circuit and trip coil are connected, rectifier circuit is power supply circuit respectively, drive circuit and trip coil power supply, power supply circuit supplies power for undervoltage comparison circuit, drive circuit includes MOS pipe Q3 with trip coil series connection, and the PWM signal generator who is connected with MOS pipe Q3 control end, undervoltage comparison circuit gathers rectifier circuit's voltage signal, and according to rectifier circuit's voltage signal drive PWM signal generator successively output high level signal and PWM duty cycle signal, control switches on MOS pipe Q3 and supplies power for trip coil.

Preferably, the PWM signal generator is one of a DRV110 chip U2, an iC-GE chip or an iC-JE chip.

Preferably, when the PWM signal generator is a DRV110 chip U2, an eighth pin of the PWM signal generator is connected to the undervoltage comparison circuit and the resistor R7, respectively; a seventh pin of the PWM signal generator is connected to the gate of the MOS transistor Q3 and one end of the resistor R12, respectively, the other end of the resistor R12 and a fifth pin of the PWM signal generator are grounded, respectively, the drain of the MOS transistor Q3 is connected to the trip coil, and the source of the MOS transistor Q3 is grounded via the resistor R9; a fourth pin of the PWM signal generator is respectively connected with a resistor R8 and a capacitor C2, the resistor R8 is connected with the power circuit, and the capacitor C2 is grounded; the third pin of the PWM signal generator is grounded through a resistor R11; the second pin of the PWM signal generator is grounded through a resistor R10; the first pin of the PWM signal generator is connected to ground through a capacitor C6.

Preferably, the undervoltage comparison circuit comprises an operational amplifier U1, an anode power supply end of an operational amplifier U1 is connected with an output end VCC of the power supply circuit, a cathode input end of an operational amplifier U1 is connected with the output end VCC of the power supply circuit through a resistor R5, and the cathode input end of the operational amplifier U1 is connected with a cathode power supply end through a resistor R6; the positive electrode input end of the operational amplifier U1 is connected with the output end of the rectifying circuit through a resistor R3 and a resistor R1 in sequence, and a node between the resistor R3 and the resistor R1 is grounded through a capacitor C1 and a resistor R2 respectively; the positive electrode input end of the operational amplifier U1 is connected with the output end of the operational amplifier U1 through a resistor R4, and a capacitor C5 is connected in parallel at two ends of the resistor R4.

Preferably, the power supply circuit comprises a triode Q2, an emitter of a triode Q2 is respectively connected with an output terminal VCC, a capacitor C3 and a capacitor C4, the capacitor C3 and the capacitor C4 are grounded, a collector of the triode Q2 is connected with an output terminal of the rectifying circuit through a resistor R17, a collector of the triode Q2 is respectively connected with a base of a triode Q2 through a static resistor R16 and a resistor R18, and a base of the triode Q2 is grounded through a voltage regulator tube ZD 1.

Preferably, the rectifier circuit comprises a rectifier bridge D1 and a voltage dependent resistor RV connected in parallel between two input ends of the rectifier bridge D1, one output end of the rectifier bridge D1 is grounded, and the other output end of the rectifier bridge D1 is connected with the power supply circuit, the undervoltage comparison circuit, the driving circuit and the trip coil respectively.

Preferably, a freewheeling diode D2 is connected in parallel to two ends of the trip coil.

The utility model discloses an under-voltage release, successively export high level signal and PWM duty cycle signal through PWM signal generator, produce PWM duty cycle signal, when PWM duty cycle signal replaces high level signal to switch on MOS pipe Q3, can reduce the electric current through trip coil, realize energy-concerving and environment-protective and reduce calorific function, need not produce PWM duty cycle signal through the singlechip, the step to singlechip programming has been saved, also need not middle PWM driver chip, it enlargies the link to need not middle signal, the PWM duty cycle signal of the direct output of PWM signal generator is also more stable. In addition, the output signal of the undervoltage comparison circuit is used for directly driving the PWM signal generator, sampling is not carried out through a single chip microcomputer, and the undervoltage comparison circuit has the advantages of being simple in structure and low in cost.

Drawings

Fig. 1 is an overall electrical schematic diagram of an under-voltage release according to an embodiment of the present invention;

fig. 2 is a specific electrical schematic diagram of an under-voltage release according to an embodiment of the present invention;

fig. 3 is a waveform diagram of an output of a PWM signal generator according to an embodiment of the present invention.

Detailed Description

As shown in fig. 1-2, the utility model discloses an under-voltage release is including the power supply circuit 102 that connects gradually, under-voltage comparison circuit 103, drive circuit 104 and trip coil 105, and respectively with power supply circuit 102, under-voltage comparison circuit 103, the rectifier circuit 101 that drive circuit 104 and trip coil 105 are connected, rectifier circuit 101 is power supply circuit 102 respectively, drive circuit 104 and trip coil 105 power supply, power supply circuit 102 is the power supply of under-voltage comparison circuit 103, drive circuit 104 includes MOS pipe Q3 with trip coil 105 series connection, and the PWM signal generator who is connected with MOS pipe Q3 control end, under-voltage comparison circuit 103 gathers rectifier circuit 101's voltage signal, and according to rectifier circuit 101's voltage signal drive PWM signal generator successively output high level signal and PWM duty cycle signal, control switch on MOS pipe Q3 is for trip coil 105 power supply.

The utility model discloses an under-voltage release, successively export high level signal and PWM duty cycle signal through PWM signal generator, produce PWM duty cycle signal, when PWM duty cycle signal replaces high level signal to switch on MOS pipe Q3, can reduce the electric current through trip coil 105, realize energy-concerving and environment-protective and reduce calorific function, need not produce PWM duty cycle signal through the singlechip, the step to singlechip programming has been saved, also need not middle PWM drive chip, it enlargies the link to need not intermediate signal, the PWM duty cycle signal of the direct output of PWM signal generator is also more stable.

In addition, the output signal of the undervoltage comparison circuit 103 is used for directly driving the PWM signal generator, and sampling is not performed through a single chip, so that the undervoltage comparison circuit has the characteristics of simple structure and low cost.

The following describes the specific implementation of the under-voltage release according to the present invention with reference to the embodiments shown in fig. 1 to 3. The utility model discloses an under-voltage release is not limited to the description of following embodiment.

As shown in fig. 1 and 3, when the PWM signal generator of this embodiment receives an enable signal input by the under-voltage comparison circuit 103, the PWM signal generator first outputs a continuous high level signal to turn on the MOS transistor Q3 for a period of time (Tkeep), so that a large current passes through the trip coil 105 and attracts an iron core (not shown in the figure) to move to a position, and then continuously outputs a PWM duty ratio signal to replace the high level signal to turn on the MOS transistor Q3, so that a small current passes through the trip coil 105 and attracts the iron core to be kept at the position, and the PWM duty ratio signal replaces the high level signal to turn on the MOS transistor Q3, so that the average power passing through the trip coil 105 is reduced, a small attracting force is generated to keep the attraction state of the iron core, and the heat generation amount is reduced.

The model of the PWM signal generator of this embodiment is DRV110, and it may also be iC-GE or iC-JE, or the signal generator of the same type with similar function generates PWM duty ratio signal, all belong to the protection scope of the present invention.

Specifically, when the PWM signal generator of this embodiment uses the DRV110 chip U2, and the eighth pin of the PWM signal generator receives the high-level enable signal of the undervoltage comparison circuit 103, the seventh pin of the PWM signal generator turns on the MOS transistor Q3 to supply power to the trip coil 105;

an eighth pin of the PWM signal generator is connected to an output terminal of an operational amplifier U1 of the undervoltage comparison circuit 103 and the resistor R7, respectively, and the resistor R7 is configured to pull down an input enable signal;

a seventh pin of the PWM signal generator is connected to the gate of the MOS transistor Q3 and one end of the resistor R12, the other end of the resistor R12 and a fifth pin of the PWM signal generator are grounded, the resistor R12 is an output pull-down resistor, the drain of the MOS transistor Q3 is connected to the trip coil 105, the source of the MOS transistor Q3 is grounded via the resistor R9, and the resistor R9 is connected to a sixth pin of the PWM signal generator for feeding back the supply voltage;

a fourth pin of the PWM signal generator is connected to a resistor R8 and a capacitor C2, respectively, the resistor R8 is connected to the power circuit 102, the capacitor C2 is grounded, the capacitor C2 is used for filtering the PWM signal generator, and the resistor R8 is used for limiting the current of the PWM signal generator;

the third pin of the PWM signal generator is grounded through a resistor R11, and the resistor R11 is used for setting the frequency of a PWM duty cycle signal of the PWM signal generator;

the second pin of the PWM signal generator is grounded through a resistor R10, and the resistor R10 is used for setting the peak value of the output voltage of the PWM signal generator;

the first pin of the PWM signal generator is grounded through a capacitor C6, and the capacitor C6 is used for setting the high level output time Tkeep of the PWM signal generator.

As shown in fig. 1, the undervoltage comparing circuit 103 of the present embodiment is composed of an operational amplifier U1, the operational amplifier U1 compares a voltage signal output by the rectifying circuit 101 with a set threshold, when the voltage signal is greater than the threshold, the operational amplifier U1 outputs an enable signal to the PWM signal generator, and when the voltage signal is lower than the threshold, the operational amplifier U1 outputs a low level. The output signal of the undervoltage comparison circuit 103 of this embodiment is directly used for directly driving the PWM signal generator, and sampling by a single chip microcomputer is not required, so that the structure can be further simplified.

Specifically, the positive power supply end of the operational amplifier U1 is connected to the output end VCC of the power supply circuit 102, the negative input end of the operational amplifier U1 is also connected to the output end VCC of the power supply circuit 102 through a resistor R5, and the negative input end of the operational amplifier U1 is connected to the negative power supply end through a resistor R6; the positive electrode input end of the operational amplifier U1 is connected with the output end of the rectifying circuit 101 through a resistor R3 and a resistor R1 in sequence, and a node between the resistor R3 and the resistor R1 is grounded through a capacitor C1 and a resistor R2 respectively; the positive electrode input end of the operational amplifier U1 is connected with the output end of the operational amplifier U1 through a resistor R4, and a capacitor C5 is connected in parallel at two ends of the resistor R4.

When the voltage signal of the rectifying circuit 101 is greater than a set threshold value, the operational amplifier U1 provides an enable signal for the PWM signal generator, the PWM signal generator outputs a high level signal to supply power to the trip coil 105 first, so that the trip coil 105 attracts the iron core to move and compresses a spring (not shown in the figure), and the PWM signal generator outputs a PWM duty ratio signal to supply power to the trip coil 105, so that the magnetic force of the trip coil 105 attracting the iron core is balanced with the elastic force of the spring acting on the iron core;

when the voltage signal of the rectifying circuit 101 is smaller than a set threshold value, the operational amplifier U1 stops generating an enable signal, the PWM signal generator turns off the MOS transistor Q3 and stops supplying power to the trip coil 105, the magnetic force of the trip coil 105 disappears, and the spring releases energy to drive the iron core to trip the operating mechanism, so as to drive the circuit breaker to trip and realize protection.

As shown in fig. 1, the rectifier circuit 101 of the present embodiment is used to rectify an input 120V or 220V ac into a dc, so that the under-voltage trip device can be used for both ac and dc, and has a wide application voltage range, and does not require a complicated voltage conversion circuit or voltage regulator circuit, and for example, when DRV110 is used as the signal generator U2, the rectifier circuit can be applied to 120V or 230V ac, and can also be applied to 16V to 48V dc.

The rectifying circuit 101 comprises a rectifying bridge D1 and a voltage dependent resistor RV connected in parallel between two input ends of the rectifying bridge D1, one output end of the rectifying bridge D1 is grounded, the other output end of the rectifying bridge D1 is respectively connected with the power circuit 102, the under-voltage comparison circuit 103, the driving circuit 104 and the trip coil 105, and two ends of the trip coil 105 are connected in parallel with a freewheeling diode D2. Of course, the rectifying circuit 101 may not be provided, and the direct current of 16V to 48V may be directly input to satisfy the voltage level of the product design.

As shown in fig. 1, the power circuit 102 of this embodiment generates 11.3V voltage to supply power to the operational amplifier U1 through the output terminal VCC. Specifically, the power circuit 102 includes a triode Q2, an emitter of the triode Q2 is respectively connected with an output terminal VCC, a capacitor C3 and a capacitor C4, the capacitor C3 and the capacitor C4 are grounded, a collector of the triode Q2 is connected with the output terminal of the rectifier circuit 101 through a resistor R17, a collector of the triode Q2 is respectively connected with a base of the triode Q2 through a static resistor R16 and a resistor R18, and a base of the triode Q2 is grounded through a voltage regulator ZD 1. The undervoltage comparison circuit of the embodiment directly outputs the VCC power supply from the power module, and the connection relation is simpler. Of course, the power circuit 102 may be configured by other linear voltage reduction modes or switching power supply voltage reduction modes, which all belong to the protection scope of the present invention.

The foregoing is a more detailed description of the present invention, taken in conjunction with the specific preferred embodiments thereof, and it is not intended that the invention be limited to the specific embodiments shown and described. To the utility model belongs to the technical field of ordinary technical personnel, do not deviate from the utility model discloses under the prerequisite of design, can also make a plurality of simple deductions or replacement, all should regard as belonging to the utility model discloses a protection scope.

Claims

1. An undervoltage release, its characterized in that: comprises a power supply circuit (102), an undervoltage comparison circuit (103), a drive circuit (104) and a trip coil (105) which are connected in sequence, and a rectifying circuit (101) respectively connected with the power circuit (102), the undervoltage comparison circuit (103), the driving circuit (104) and the trip coil (105), wherein the rectifying circuit (101) respectively supplies power to the power circuit (102), the driving circuit (104) and the trip coil (105), the power circuit (102) supplies power to the undervoltage comparison circuit (103), the driving circuit (104) comprises a MOS tube Q3 connected with the trip coil (105) in series, and a PWM signal generator connected with the control end of the MOS tube Q3, an under-voltage comparison circuit (103) collects the voltage signal of the rectification circuit (101), and the PWM signal generator is driven to output a high level signal and a PWM duty ratio signal according to a voltage signal of the rectifying circuit (101), and the MOS tube Q3 is controlled to be conducted to supply power to the trip coil (105).

2. The undervoltage trip unit of claim 1, wherein: the PWM signal generator is one of a DRV110 chip U2, an iC-GE chip or an iC-JE chip.

3. The undervoltage trip unit of claim 2, wherein: when the PWM signal generator is a DRV110 chip U2, an eighth pin of the PWM signal generator is respectively connected with an undervoltage comparison circuit (103) and a resistor R7; a seventh pin of the PWM signal generator is respectively connected with a grid electrode of a MOS transistor Q3 and one end of a resistor R12, the other end of the resistor R12 and a fifth pin of the PWM signal generator are respectively grounded, a drain electrode of the MOS transistor Q3 is connected with a trip coil (105), and a source electrode of the MOS transistor Q3 is grounded through a resistor R9; a fourth pin of the PWM signal generator is respectively connected with a resistor R8 and a capacitor C2, the resistor R8 is connected with a power circuit (102), and the capacitor C2 is grounded; the third pin of the PWM signal generator is grounded through a resistor R11; the second pin of the PWM signal generator is grounded through a resistor R10; the first pin of the PWM signal generator is connected to ground through a capacitor C6.

4. The undervoltage trip unit of claim 1, wherein: the undervoltage comparison circuit (103) comprises an operational amplifier U1, an anode power supply end of an operational amplifier U1 is connected with an output end VCC of a power supply circuit (102), a cathode input end of an operational amplifier U1 is connected with the output end VCC of the power supply circuit (102) through a resistor R5, and the cathode input end of the operational amplifier U1 is connected with the cathode power supply end through a resistor R6; the positive electrode input end of the operational amplifier U1 is connected with the output end of the rectifying circuit (101) through a resistor R3 and a resistor R1 in sequence, and a node between the resistor R3 and the resistor R1 is grounded through a capacitor C1 and a resistor R2 respectively; the positive electrode input end of the operational amplifier U1 is connected with the output end of the operational amplifier U1 through a resistor R4, and a capacitor C5 is connected in parallel at two ends of the resistor R4.

5. The undervoltage trip unit of claim 1, wherein: the power supply circuit (102) comprises a triode Q2, an emitter of a triode Q2 is respectively connected with an output end VCC, a capacitor C3 and a capacitor C4, the capacitor C3 and the capacitor C4 are grounded, a collector of the triode Q2 is connected with an output end of the rectifying circuit (101) through a resistor R17, a collector of the triode Q2 is respectively connected with a base of a triode Q2 through a static resistor R16 and a resistor R18, and a base of the triode Q2 is grounded through a voltage stabilizing tube ZD 1.

6. The undervoltage trip unit of claim 1, wherein: the rectifying circuit (101) comprises a rectifying bridge D1 and a voltage dependent resistor RV connected in parallel between two input ends of the rectifying bridge D1, one output end of the rectifying bridge D1 is grounded, and the other output end of the rectifying bridge D1 is connected with the power supply circuit (102), the under-voltage comparison circuit (103), the driving circuit (104) and the trip coil (105) respectively.

7. The undervoltage trip unit of claim 1, wherein: and a freewheeling diode D2 is connected in parallel with two ends of the trip coil (105).