CN103500984B - Circuit of miniature residual current circuit breaker - Google Patents

Abstract

The present invention relates to a small residual current circuit breaker circuit, including: a power supply circuit, characterized in that the small residual current circuit breaker circuit also includes: a residual current signal conditioning circuit; a residual current detection control unit; The required circuit; the residual current test circuit; the tripping circuit; wherein, the residual current signal conditioning circuit, the residual current detection control unit, the circuit required by the residual current detection control unit, the residual current test circuit, and the tripping circuit are connected in sequence. The small residual current circuit breaker circuit provided by the present invention reduces the temperature rise of the drop-down resistor and improves the reliability of the product; it improves the phenomenon that the product has low anti-pulse group ability and easily leads to false tripping when there is no external voltage stabilizing circuit. The circuit design is simple, the anti-EMC performance is strong and the reliability is high, and it is more in line with the actual demand of the small residual current circuit breaker.

Description

Small residual current circuit breaker circuit

technical field

The invention relates to the field of circuit breaker circuits, and more specifically relates to a small residual current circuit breaker circuit.

Background technique

At present, full-wave rectification and resistance step-down are commonly used in the power supply circuit of small residual current circuit breakers. Because the DC output voltage of the full-wave rectification circuit is about 0.9 times the AC input voltage; at the same time, in order to cooperate with the residual current detection unit. Due to the requirements of current and product structure volume, the resistance step-down circuit cannot use a high-power, large-value drop-down resistor. The common method is to use two resistors in series to reduce the temperature rise, so that the temperature rise of the drop-down resistor during normal operation Relatively high, thereby reducing the reliability of the entire circuit; at the same time, because there is no external voltage stabilizing circuit, but only the internal voltage stabilizing circuit of the residual current detection control unit is used, resulting in poor anti-burst interference of the product, and prone to false tripping .

Contents of the invention

The technical problem to be solved by the present invention is to provide a small residual current circuit breaker for the above-mentioned products in the prior art, which have poor anti-burst interference ability, are prone to false tripping phenomenon and the temperature rise of the drop-down resistor in the power supply circuit. The device circuit at least includes: a power supply circuit; a residual current signal conditioning circuit; a residual current detection control unit; a circuit required by the residual current detection control unit; a residual current test circuit; a tripping circuit; wherein, the residual current signal conditioning circuit, The residual current detection control unit, the circuit required by the residual current detection control unit, the residual current test circuit, and the tripping circuit are connected in sequence.

In the small residual current circuit breaker circuit of the present invention, the residual current signal conditioning circuit is composed of resistors R3, R4, R5, capacitors C2, C6, C8, C9 and diode D4; resistors R3, R4, R5 are connected in series , capacitors C6, C8, and C9 are connected in series, capacitor C2 is connected in series between resistor R4 and resistor R5, and diode D4 is connected in parallel with resistor R3.

In the small residual current circuit breaker circuit of the present invention, the power supply circuit is composed of a surge suppression circuit, a half-wave rectification circuit, a resistance step-down circuit, an external voltage stabilizing circuit, a filter circuit and a release; wherein the The surge suppression circuit is composed of varistor MYR1, the half-wave rectification circuit is composed of diode D1, the resistance step-down circuit is composed of resistor R2, the external voltage stabilizing circuit is composed of Zener diode D2, and the filter circuit is composed of capacitor C1. The device is composed of the trip unit Trip.

In the small residual current circuit breaker circuit of the present invention, the residual current detection control unit is composed of a residual current detection integrated circuit U1.

In the small residual current circuit breaker circuit of the present invention, the residual current test circuit is composed of a resistor R1.

In the small residual current circuit breaker circuit of the present invention, the tripping circuit is composed of a thyristor D3, a resistor R6 and capacitors C5 and C7.

In the small residual current circuit breaker circuit of the present invention, the residual current detection integrated circuit U1 refers to VG54123.

In the small residual current circuit breaker circuit of the present invention, the circuit required by the residual current detection control unit is composed of capacitors C3 and C4; the capacitor C3 is connected to the pin 6 of the residual current detection integrated circuit U1; the capacitor C4 is connected with pin 4 and pin 5 of the residual current detection integrated circuit U1.

In the small residual current circuit breaker circuit of the present invention, it is characterized in that a capacitor C2 is connected between pin 1 and pin 2 of the residual current detection integrated circuit U1; A capacitor C1 is connected between pin 3 and pin 8.

Implementing the small residual current circuit breaker circuit of the present invention has the following beneficial effects: the temperature rise of the voltage-dropping resistor in the power supply circuit is reduced, and the reliability of the product is improved; The phenomenon of false tripping is caused, the whole circuit design is simple, the anti-EMC performance is strong and the reliability is high, which is more in line with the actual needs of small residual current circuit breakers.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is a schematic diagram of a power supply circuit of a small residual current circuit breaker in the prior art;

Fig. 2 is a circuit schematic diagram of the small residual current circuit breaker of the present invention.

detailed description

Please refer to Fig. 1, Fig. 1 is a schematic diagram of a power supply circuit of a small residual current circuit breaker in the prior art. As shown in Figure 1, full-wave rectification and resistance step-down are generally used in the prior art, and its disadvantages are: the temperature rise of the step-down resistor is relatively high during normal operation, thereby reducing the reliability of the entire circuit; since there is no external Voltage stabilization circuit, but only use the voltage stabilization circuit inside the residual current detection control unit, resulting in poor ability of the product to resist pulse group interference, and prone to false tripping.

Please refer to Fig. 2, Fig. 2 is a circuit schematic diagram of a small residual current circuit breaker of the present invention. As shown in Figure 2, a small residual current circuit breaker circuit includes: a power supply circuit, and also includes: a residual current signal conditioning circuit; a residual current detection control unit; a circuit required by the residual current detection control unit; a residual current test circuit; A buckle circuit; wherein, the residual current signal conditioning circuit, the residual current detection control unit, the circuit required by the residual current detection control unit, the residual current test circuit, and the tripping circuit are connected in sequence.

Preferably, the residual current signal conditioning circuit is composed of resistors R3, R4, R5, capacitors C2, C6, C8, C9 and diode D4; resistors R3, R4, R5 are connected in series, capacitors C6, C8, C9 are connected in series, capacitors C2 is connected in series between resistor R4 and resistor R5, and diode D4 is connected in parallel with resistor R3.

Preferably, the power supply circuit is composed of a surge suppression circuit, a half-wave rectification circuit, a resistor step-down circuit, an external voltage stabilizing circuit, a filter circuit and a release; wherein the surge suppression circuit is composed of a piezoresistor MYR1 , The half-wave rectifier circuit is composed of diode D1, the resistance step-down circuit is composed of resistor R2, the external voltage stabilizing circuit is composed of Zener diode D2, the filter circuit is composed of capacitor C1, and the trip unit is composed of trip unit Trip.

Preferably, the residual current detection control unit is composed of a residual current detection integrated circuit U1.

Preferably, the residual current test circuit is composed of a resistor R1.

Preferably, in the small residual current circuit breaker circuit, the tripping circuit is composed of a thyristor D3, a resistor R6 and capacitors C5 and C7.

Preferably, in the small residual current circuit breaker circuit, the residual current detection integrated circuit U1 refers to VG54123.

Preferably, the residual current detection control unit circuit is composed of capacitors C3 and C4; the capacitor C3 is connected to the pin 6 of the residual current detection integrated circuit U1; the capacitor C4 is connected to the pin 6 of the residual current detection integrated circuit U1 Pin 4 and pin 5 are connected.

Preferably, a capacitor C2 is connected between pin 1 and pin 2 of the residual current detection integrated circuit U1; a capacitor C1 is connected between pin 3 and pin 8 of the residual current detection integrated circuit U1.

The uniqueness of the present invention lies in the form of half-wave rectification and the use of an external voltage stabilizing circuit at the same time.

Through the design of the above schematic diagram, the present invention has the beneficial effects as follows: 1. The rectifier circuit in the power supply circuit of the small residual current circuit breaker of the present invention adopts the form of half-wave rectification, and its DC output voltage is approximately equal to 0.45 times of the AC input voltage, The input voltage of the entire resistor step-down circuit is reduced by about half compared with the step-down circuit in the power supply circuit of a small residual current circuit breaker commonly used at present, so there is no need to use a high-power, large-value drop-down resistor, and no need to connect two resistors in series The method to reduce the temperature rise caused by resistance heating not only simplifies the design of the circuit, but also greatly reduces the temperature rise of the drop-down resistor and improves the reliability of the product; 2. The use of an external voltage regulator circuit greatly improves the temperature without an external voltage regulator circuit. The ability of the product to resist bursts is low, which can easily lead to false tripping; 3. The whole circuit design is simple, with strong anti-EMC performance and high reliability, which is more in line with the actual needs of small residual current circuit breakers.

The present invention has been described based on specific embodiments, but those skilled in the art will understand that various changes and equivalent substitutions can be made without departing from the scope of the present invention. In addition, in order to adapt to the specific occasion of the technology of the present invention, many modifications can be made to the present invention without departing from its protection scope. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed herein, but include all embodiments falling within the scope of the appended claims.

Claims (7)

1. a circuit of miniature residual current circuit breaker, including: power circuit, it is characterised in that institute State circuit of miniature residual current circuit breaker also to include:

Residual current signal conditioning circuit；

Residual current detection control unit；

Circuit needed for residual current detection control unit；

Residual current hookup；

Trip circuit；

Wherein, described residual current signal conditioning circuit, residual current detection control unit, residue Needed for current detecting control unit, circuit, residual current hookup, trip circuit are sequentially connected；

Described residual current signal conditioning circuit by resistance R3, R4, R5, electric capacity C2, C6, C8, C9 and diode D4 composition；Resistance R3, R4, R5 are connected in series, electric capacity C6, C8, C9 is connected in series, and electric capacity C2 is connected in series between resistance R4 and resistance R5, diode D4 is connected in parallel with resistance R3；

Described power circuit by surge restraint circuit, half-wave rectifying circuit, resistance reduction voltage circuit, External mu balanced circuit, filter circuit and electrical apparatus release composition；Wherein said surge restraint circuit Being made up of piezo-resistance MYR1, half-wave rectifying circuit is made up of diode D1, and resistance is depressured Electricity routing resistance R2 is constituted, and external mu balanced circuit is made up of Zener diode D2, filtered electrical Routing capacitance C1 is constituted, and electrical apparatus release is made up of electrical apparatus release Trip.

Circuit of miniature residual current circuit breaker the most according to claim 1, it is characterised in that institute State residual current detection control unit to be made up of residual current detection integrated circuit U1.

Circuit of miniature residual current circuit breaker the most according to claim 1, it is characterised in that institute State residual current hookup to be made up of resistance R1.

Circuit of miniature residual current circuit breaker the most according to claim 1, it is characterised in that institute State trip circuit to be made up of controllable silicon D3, resistance R6 and electric capacity C5, C7.

Circuit of miniature residual current circuit breaker the most according to claim 2, it is characterised in that institute State residual current detection integrated circuit U1 and refer to VG54123.

Circuit of miniature residual current circuit breaker the most according to claim 5, it is characterised in that institute State electricity routing capacitance C3, C4 composition needed for residual current detection control unit；Electric capacity C3 and institute The pin 6 of the residual current detection integrated circuit U1 stated connects；Electric capacity C4 and described residue The pin 4 of current detection IC U1, pin 5 connect.

Circuit of miniature residual current circuit breaker the most according to claim 5, it is characterised in that It is connected to electric capacity C2 between the pin 1 of described residual current detection integrated circuit U1, pin 2； It is connected to electric capacity C1 between the described pin 3 of residual current detection integrated circuit U1, pin 8.