CN105023815A - Electronic undervoltage release of plastic case type breaker - Google Patents

Abstract

The invention relates to an electronic undervoltage release of a plastic case type breaker. The electronic undervoltage release is characterized in that the electronic undervoltage release comprises an electronic step-down circuit which is composed of a binding post JP1, a transformer T1, a rectifier bridge B1, a capacitor C1, a capacitor C2, a three-terminal regulator U1, resistors R1-R7, an operational amplifier U2, a voltage regulator tube VD1, a field effect transistor Q1 and an electromagnetic coil L. The line is simple, and only a position of one accessory in the breaker is occupied; secondly, when the circuit is connected with a main loop and the operates, because the DC electromagnetic coil is used, and a voltage is low, an electrical noise is unlikely to occur basically; and, finally, the circuit uses a comparator, so resistance values of voltage-divider resistors can be adjusted to perform setting according to undervoltage protection, the electronic undervoltage release is convenient and fast, and the electronic undervoltage release has the advantage of high protection precision by utilizing the comparator to distinguish and has other advantages.

Description

Moulded case circuit breaker electronics under-voltage release

Technical field

The invention belongs to a kind of electronics under-voltage protection tripper for low-voltage circuit breaker, particularly relate to a kind of moulded case circuit breaker electronics under-voltage release.

Background technology

Current known low-voltage circuit breaker, as the major control of 380V/AC and 230V/AC power supply-distribution system and protection component, is widely used in protecting circuit overload, short circuit, earth fault in China's supply and distribution network, and distributes the effect of electric energy, but owing to itself not possessing the protection of overvoltage, the voltage function such as under-voltage, when stating voltage protection function in realization, need to install special under voltage or overvoltage protection release additional, under-voltage release on existing market be all use 380V/AC or 230V/AC high-voltage electromagnetic coil dead electricity, control the iron core of solenoid, indirectly drive breaker tripping mechanism to realize under voltage protection to realize, this mode relies on protection voltage itself and is greater than to the electromagnetic force that solenoid provides and releases power spring force, maintenance solenoid iron core is made to be in absorbing state, do not drive breaker mechanism, when protected brownout, electromagnetic force can not keep iron core, iron core release drives breaker mechanism to realize, this kind of method pair and solenoid wire diameter error, number of turn error, the elasticated of winding process coil has strict requirement, above any one occurs that error will cause under voltage protection error too high, protection is inaccurate, cause malfunction or tripping situation, it is when long-term work in addition, owing to working long hours in high voltage "on" position, solenoid is caused easily to generate heat scaling loss, the faults such as electrical noise and environmental pollution.

Summary of the invention

The present invention provides a kind of moulded case circuit breaker electronics under-voltage release possessing electronics reduction voltage circuit for solving in known technology the technical problem that exists.

The technical scheme that the present invention takes for the technical problem existed in solution known technology is: its voltage of protected power circuit is connected to binding post (JP1), one end of binding post (JP1) is connected with transformer (T1) input one end, and the other end of binding post (JP1) is connected with the other end of transformer (T1) input; Rectifier bridge (B1) one input is connected with transformer (T1) output, and rectifier bridge (B1) another input is connected with another output of transformer (T1); Rectifier bridge (B1) anode output end is as circuit integrity GND potential reference point and electric capacity (C1) negative electrode, the GND end of three terminal regulator (U1), with resistance (R1) one end, resistance (R4) one end, electric capacity (C2) one end, operational amplifier (U2A) negative power end, voltage-stabiliser tube (VD1) anode, field effect transistor (Q1) one end connects; Rectifier bridge (B1) cathode end is as the overall positive potential normal power of electric current and resistance (R1) other end, electric capacity (C1) other end, the Vin end of three terminal regulator (U1), resistance (R2) one end, operational amplifier is (U2A) power end just, and resistance (R7) one end connects; Resistance (R4) other end and resistance (R2) other end, operational amplifier (U2A) in-phase input end connects; + 5V end and resistance (R3) one end of three terminal regulator (U1), electric capacity (C2) other end connects; Resistance (R3) other end is connected with operational amplifier (U2A) inverting input; Operational amplifier (U2A) output is connected with resistance (R6) one end; Resistance (R6) other end and resistance (R5) one end, voltage-stabiliser tube (VD1) negative electrode connects; Resistance (R5) other end is connected with field effect transistor (Q1) drive end; Field effect transistor (Q1) one end is connected with solenoid (L) one end; Solenoid (L) other end is connected with resistance (R7) other end.

The advantage that the present invention has and good effect are: circuit first of the present invention is simple, only takies the position of a circuit breaker internal annex; Its secondary circuit, when connecting major loop and running, is d-c solenoid because of what use, and is that after step-down, low-voltage, as driving voltage, therefore there will not be electrical noise substantially; Solenoid ensures the coil voltage of iron core not driving condition, is significantly less than wire gauge regulation rated current, also there will not be the aging dielectric strength that causes of generating heat in long-term galvanization to reduce, occurs scaling loss; Circuit because uses comparator to carry out judging under-voltage fault in addition, and under-voltage protection adjustable divider resistance resistance is adjusted, convenient and swift, utilizes comparator to carry out differentiating the high discrete shortcoming occurring under-voltage protection tripping and malfunction avoided because of manufacturing process of protection precision.

Accompanying drawing explanation

Fig. 1 is electrical schematic diagram of the present invention.

Embodiment

For content of the present invention, Characteristic can be understood further, hereby exemplify following examples, and coordinate accompanying drawing to be described in detail as follows:

As shown in Figure 1, its voltage of protected power circuit is connected to binding post JP1, and one end of binding post JP1 is connected with transformer T1 input one end, and the other end of binding post JP1 is connected with the other end of transformer T1 input; Rectifier bridge B1 mono-input is connected with transformer T1 mono-output, and another input of rectifier bridge B1 is connected with another output of transformer T1; Rectifier bridge B1 anode output end is as circuit integrity GND potential reference point and electric capacity C1 negative electrode, and the GND end of three terminal regulator U1, with resistance R1 one end, resistance R4 one end, electric capacity C2 one end, operational amplifier U2A negative power end, voltage-stabiliser tube VD1 anode, field effect transistor Q1 one end connects; Rectifier bridge B1 cathode end as the overall positive potential normal power of electric current and the resistance R1 other end, the electric capacity C1 other end, the Vin end of three terminal regulator U1, resistance R2 one end, the positive U2A power end of operational amplifier, the connection of resistance R7 one end; The resistance R4 other end and the resistance R2 other end, operational amplifier U2A in-phase input end connects; + 5V end and resistance R3 one end of three terminal regulator U1, the electric capacity C2 other end connects; The resistance R3 other end is connected with operational amplifier U2A inverting input; Operational amplifier U2A output is connected with resistance R6 one end; The resistance R6 other end and resistance R5 one end, voltage-stabiliser tube VD1 negative electrode connects; The resistance R5 other end is connected with field effect transistor Q1 drive end; Field effect transistor Q1 one end is connected with solenoid L one end; The solenoid L other end is connected with the resistance R7 other end.

Specific works mode process is as follows: the under-voltage release that first this patent relates to is arranged on the internal accessories of breaker position needing protection circuit relevant position, major loop needs circuit 380V/AC or the 230V/AC voltage access binding post JP1 of protection, voltage is through Industrial Frequency Transformer T1 linear voltage decreasing rectifier bridge B1 rectification, electric capacity C1 filtering, resistance R1 avoids overtension to protect rear portion circuit to obtain basic DC power supply as load resistance, and it reduces with the line voltage distribution protected is proportional, three terminal regulator U1 voltage stabilizing of wherein leading up to, for after+5V output, through electric capacity C2 filtering, accesses operational amplifier U2 inverting input, as the reference voltage of the comparator be made up of operational amplifier U2 after resistance R3 current limliting, separately lead up to by divider resistance R2, R4 pair with the proportional normal power dividing potential drop reduced of protected line voltage distribution after receive operational amplifier U2 in-phase input end, when operational amplifier U2 in-phase input end voltage and line voltage distribution are higher than inverting input and reference voltage, prove that in loop, voltage is higher than the prefabricated under-voltage set point of setting, there is not under-voltage fault, now operational amplifier U2 lead-out terminal is high potential, current potential is clamped down on output voltage by current-limiting resistance R6 and voltage-stabiliser tube VD1 and is protected on after-applied scene effect pipe Q1 trigger end, field effect transistor Q1 conducting, solenoid L is energized by current-limiting resistance R7, solenoid L does not drive breaker tripping mechanism by electromagnetic force constraint iron-core coil, under-voltage fault does not occur circuit now residing for circuit breaker can normally closed circuit breaker or cut-off breaker, when operational amplifier U2 in-phase input end voltage and line voltage distribution are lower than inverting input and reference voltage, prove that in loop, voltage is lower than the prefabricated under-voltage set point of setting, there is under-voltage fault, now operational amplifier U2 output is electronegative potential, current potential is clamped down on output voltage by current-limiting resistance R6 and voltage-stabiliser tube VD1 and is protected on after-applied scene effect pipe Q1 trigger end, field effect transistor Q1 ends, solenoid L power-off, solenoid L electromagnetic force disappears, iron-core coil cannot be retrained, iron core drives breaker tripping mechanism, there is under-voltage fault in the circuit now residing for circuit breaker, breaker tripping mechanism will be driven to make circuit breaker tripping by electromagnet core if circuit breaker is in closed on-position circuit breaker, disconnect under-voltage route protection power consumption equipment, if circuit breaker is in open position circuit breaker, electromagnet core locking breaker tripping mechanism is that trip positions makes circuit breaker be in open position cannot to close under-voltage route protection power consumption equipment.

Claims (1)

1. a moulded case circuit breaker electronics under-voltage release, it is characterized in that: its voltage of protected power circuit is connected to binding post (JP1), one end of binding post (JP1) is connected with transformer (T1) input one end, and the other end of binding post (JP1) is connected with the other end of transformer (T1) input; Rectifier bridge (B1) one input is connected with transformer (T1) output, and rectifier bridge (B1) another input is connected with another output of transformer (T1); Rectifier bridge (B1) anode output end is as circuit integrity GND potential reference point and electric capacity (C1) negative electrode, the GND end of three terminal regulator (U1), with resistance (R1) one end, resistance (R4) one end, electric capacity (C2) one end, operational amplifier (U2A) negative power end, voltage-stabiliser tube (VD1) anode, field effect transistor (Q1) one end connects; Rectifier bridge (B1) cathode end is as the overall positive potential normal power of electric current and resistance (R1) other end, electric capacity (C1) other end, the Vin end of three terminal regulator (U1), resistance (R2) one end, operational amplifier is (U2A) power end just, and resistance (R7) one end connects; Resistance (R4) other end and resistance (R2) other end, operational amplifier (U2A) in-phase input end connects; + 5V end and resistance (R3) one end of three terminal regulator (U1), electric capacity (C2) other end connects; Resistance (R3) other end is connected with operational amplifier (U2A) inverting input; Operational amplifier (U2A) output is connected with resistance (R6) one end; Resistance (R6) other end and resistance (R5) one end, voltage-stabiliser tube (VD1) negative electrode connects; Resistance (R5) other end is connected with field effect transistor (Q1) drive end; Field effect transistor (Q1) one end is connected with solenoid (L) one end; Solenoid (L) other end is connected with resistance (R7) other end.