CN2196816Y

CN2196816Y - Arc-less cut-off A.C. contactor

Info

Publication number: CN2196816Y
Application number: CN 94240006
Authority: CN
Inventors: 倪仁权
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-03-18
Filing date: 1994-03-18
Publication date: 1995-05-10
Anticipated expiration: 2004-03-18

Abstract

The utility model relates to an arc-less cut-off alternating current contactor, comprising a solid state switch cover replacing the arc extinguishing cover of a traditional alternating current contactor. The thyristor in the solid state switch is connected with the main contact of a contactor in parallel. The control circuit of the thyristor is connected with a mechanical delay switch which is driven by the moving iron core of the contactor. The utility model realizes that the main contact of the contactor switches on a circuit and loads current. The solid state switch switches off the current which is a zero passage when the circuit is broken, which makes the main contact of the contactor not produce arc. The utility model can replace all the traditional alternating current contactors with the arc extinguishing covers in the application of the circuit.

Description

Arc-less cut-off A.C. contactor

It is the arc-extinguish chamber that replaces the conventional AC contactor with the solid-state switch cover that the present invention does not have arc disconnection A.C. contactor.Three thyristors that are equipped with in the solid-state switch cover are in parallel with the three-phase main contact of contactor respectively, and the connecting and disconnecting of three thyristor control loops are to be contained on the solid-state switch cover side and the moving mechanical delay switch that drives unshakable in one's determination of contactor is controlled by one.

Be widely used in the A.C. contactor in the circuit control, the electric arc that produces when the open circuit electric current is the main cause that causes contact to damage, and electric arc can produce electromagnetic interference, causes the electronic circuit misoperation.

Make alternating-current switch with thyristor, have life-span length, no-spark, no electromagnetic interference, but overload capacity is poor, so more as solid-state relay.

By the thyristor breaking current, its technical advance is that the electric specialty personnel thirst for the contactor loaded current.Low-voltage electrical apparatus (1993NO.6P40) publication Xunda Elevator Co., Ltd., Suzhou executes prosperous " the no arc switching device of the novel practical " literary composition write of great waves, has specifically discussed the superiority of contactor and thyristor reasonable combination.Accompanying drawing 1 is in this article the no arc switching device to be used in 45KW three-phase resistance stove to realize the furnace temperature electrical schematic diagram of control automatically.As shown, contactor KM main contact is in parallel with bidirectional thyristor in major loop.When switch S A dials at automated location a, furnace temperature can remain on automatically to fixed temperature, and when being heated to furnace temperature when reaching set-point, the normally open contact T of temperature controller opens, and V4 turn-offs, the K1 dead electricity, and KM discharges.Because still adhesive of K2, the gate pole trigger signal source of V1-V3 still is in contact condition, and then the electric current of the two-way parallel branch that bidirectional thyristor and contactor are formed in the KM breaking course distributes constantly change.When the gap appears in the KM main contact, all load currents are by bidirectional thyristor, and bidirectional thyristor turn-offs promptly when current over-zero voluntarily, cuts off the electricity supply, and realize that furnace temperature controls automatically.This no arc switching device, it is not that the control of the trigger signal source K2 of thyristor realizes by control circuit repeat circuit K1 and K2 the product of thyristor and contactor formation one.

The objective of the invention is solid-state switch and A.C. contactor are combined into one, become no arc and disconnect A.C. contactor.Realization is connected circuit and loaded current by the main contact of contactor, when dividing deenergizing, by solid-state switch turn-off current when the current over-zero, makes main contact not produce electric arc.

Accompanying drawing 2 is structural representations that no arc disconnects A.C. contactor, thyristor 2 is connected in parallel on the main noddle on contactor 1, the control loop of thyristor 2 is delayed time and is connected or time-delay disconnects by the contact 5 of mechanical delay switch, the action of contact 5 is driven by U type frame (or square hole frame) 4, link rod 3 is by moving unshakable in one's determination drive of contactor, link rod 3 moves in U-shaped frame (or square hole frame) 4, constitutes the space mechanism time-delay.U-shaped frame (or square hole frame) and link rod 3 that contact 5 is housed are formed the mechanical delay switch.

The operating principle of no arc disconnection A.C. contactor is as follows: in the connection process, the moving main contact 1 that drives unshakable in one's determination of contactor is from the open position to the make position, moving iron core drives link rod 3 simultaneously and moves in the space of U-shaped frame 4, and this process U-shaped frame 4 is motionless, and contact 5 keeps open position.The moving adhesive that continues unshakable in one's determination makes main contact 1 enter the overtravel zone, and this moment, link rod 3 began to drive 4 motions of U-shaped frame, and U-shaped frame 4 drives contact 5 and enters make position, and the control loop of thyristor 2 is switched on.In the breaking course, when corresponding main contact 1 withdraws from the overtravel zone, because of the spatial movement of link rod 3 at U-shaped frame 4, the U-shaped frame is motionless, contact 5 disconnects moment at main contact 1 and still is in the close position, so thyristor 2 conductings, and load current is transferred to circulation the thyristor 2 from main contact 1.Main contact 1 is being opened when disconnecting apart from interior continuation, and link rod 3 begins to drive 4 motions of U-shaped frame, and contact 5 is opened, and the control loop of thyristor 2 is disconnected, and the load current that flows through thyristor 2 disconnects when current over-zero, realizes that load current does not have arc and cuts off.

No arc disconnects A.C. contactor and has the following advantages: 1, when connecting circuit, be that main contact is closed earlier, connect load current, just connect the control loop of thyristor subsequently, it is the connection that thyristor does not participate in circuit, therefore not having arc disconnection A.C. contactor can be the same with the conventional AC contactor, can use in AC-3 class perceptual load circuit.2, when open circuit, main contact disconnects earlier, realizes that with thyristor the circuit non-arc breaking is disconnected then, therefore can alleviate the electrical arc erosion of main contact effectively, improves the electric life of main contact.Simultaneously also make full use of thyristor allows 10 times of rated current in a cycle (20ms) overload capacity, and the release time of contactor is just all less than 20ms.

Specific embodiment of the utility model: Fig. 3 disconnects A.C. contactor with no arc to be used in the electrical schematic diagram that 45KW three-phase resistance stove realizes that furnace temperature is controlled automatically.Diagram, when switch was dialled at automated location a, furnace temperature can remain on to fixed temperature automatically.When being heated to furnace temperature when reaching set-point, the normally open contact of temperature controller T is opened, V4 turn-offs, and no arc disconnects A.C. contactor 1 coil losing electricity, 1 disjunction of three-phase main contact, before mechanical delay, switch contact 5 time-delays disconnected, load current is transferred to circulation in the thyristor 2 by main contact 1, mechanical delay switch contact 5 disconnections, and the load current that flows through thyristor turn-offs when current over-zero voluntarily, cut off the electricity supply, the realization furnace temperature is controlled automatically.

Description of drawings of the present utility model:

Fig. 1 is that prior art " the no arc switching device of Nover practical " is used in the electrical schematic diagram that 45KW three-phase resistance stove realizes that furnace temperature is controlled automatically.Among the figure: KM is an A.C. contactor, and K1 and K2 are relays, and V1～V4 is a bidirectional thyristor, and T is a temperature controller, and SA is a change over switch, and a position is that the b position is to stop automatically, and the c position is manual.FU1～FU4 is a fuse, and Rf is that heating wire R1～R4 is a resistance, and HL1 and HL2 are indicator lights.

Fig. 2 is the structural representation that no arc of the present invention disconnects A.C. contactor, and 1 is main noddle on contactor among the figure, the 2nd, the thyristor in the solid-state switch cover, the 3rd, link rod, the 4th, U-shaped frame (or square hole frame), the 5th, mechanical delay switch the contact.

Fig. 3 is that the present invention's " no arc disconnects A.C. contactor " is used in the electrical schematic diagram that 45KW three-phase resistance stove realizes that furnace temperature is controlled automatically.

Claims

1, a kind of no arc disconnection A.C. contactor that replaces original arc-extinguish chamber with the solid-state switch cover, it is characterized in that: a solid-state switch cover is housed above the contactor, thyristor 2 in the solid-state switch cover is in parallel with main noddle on contactor 1, be contained in contact 5 and U-shaped frame or square hole frame 4 on the solid-state switch cover side, contact 5 connects the control loop of thyristor 2, and U-shaped frame or square hole frame 4 are driven by the link rod 3 that is fixed on the moving iron core of contactor.

2, no arc according to claim 1 disconnects A.C. contactor, it is characterized in that: be contained in contact 5 and U-shaped frame or square hole frame 4 on the solid-state switch cover side, the link rod 3 that is fixed on the moving iron core of contactor moves in U-shaped frame or square hole frame 4.