CN2149693Y - Multi-function safety plug - Google Patents

Abstract

The utility model introduces a multi-function safety plug to meet requirements of the safe operation of various electric appliances. The multi-function safety plug is realized by that the inner part of an original plug is additionally provided with a protective tube and an overvoltage protection element. As a consequence, the multi-function safety plug has functions of over-current protection and overvoltage protection. When the power supply voltage reaches the rated voltage protection value of the safety plug, the safety plug can cut off the power supply in time to protect the safety of the electric appliances.

Description

Multi-function safety plug

The utility model has related to electrical connector, specifically a kind of plug with overvoltage, overcurrent protection function.Be applicable to being connected of various electrical appliances and power supply.

At present, along with the universal use of various household electrical appliance, it is more and more important that Electrical Safety has seemed, in the middle of this, to the most frequently used parts of power consumption equipment---and the improvement and the renewal of plug construction function have become the heat subject that people study.Manage to make plug when using, also have certain defencive function as electrical connector.Patent No. 89206174.x once disclosed a kind of plug with overvoltage and overcurrent protection function, and promptly " multifunctional protecting plug " this plug is novel, rational in infrastructure, and was subjected to user's welcome.But the overvoltage protection of this safety plug is to realize by a Zinc-oxide piezoresistor that is attempted by in the internal circuit, is to utilize the high pressure conducting of Zinc-oxide piezoresistor to realize with the overvoltage protection of electric loading.Because the Zinc-oxide piezoresistor conducting can not recover its primary characteristic after puncturing again, therefore need to change Zinc-oxide piezoresistor and just can make safety plug keep original function.Obviously very inconvenient.In addition because the not steep misoperation that causes protection device easily of volt-ampere characteristic of Zinc-oxide piezoresistor.

Be to release order of the present utility model a kind of simple in structure, cheap, easy to use, can carry out over-current over-voltage protection to electrical appliance, the multifunctional protecting plug of reliable operation is so that safety plug is able to higher generalization and use.

Task of the present utility model be by protective tube of serial connection in the circuit of plug inside and and connect a bidirectional triode thyristor and a resistance is realized, bidirectional triode thyristor and resistance are attempted by in the load circuit of protective tube back.Bidirectional triode thyristor is a kind of very good switch element, and when not having trigger current or trigger current less than a certain value, bidirectional triode thyristor is in off state.Have only when gate pole feeds certain triggering Control current, bidirectional triode thyristor is conducting work, and after trigger current minimizing or the disappearance, bidirectional triode thyristor returns to off state again.The The Trigger of Bidirectional Triode Thyristor electric current is that change with supply voltage changes in the utility model.Thereby the conducting that makes bidirectional triode thyristor is subjected to the change of supply voltage with shutoff and changes.Specific practice is, with two anodes of bidirectional triode thyristor and be connected in and use the electric loading two ends, with resistance of cross-over connection between the gate pole of bidirectional triode thyristor and one of them anode, the withstand voltage of bidirectional triode thyristor will be higher than power supply accident voltage.The conducting electric current of bidirectional triode thyristor is greater than more than the twice of electric current protective tube nominal value, and resistance is determined by the resistance that supply voltage is elevated to when needing the bidirectional triode thyristor conducting.The utility model is to realize protection work like this, supply voltage just often, needed trigger current when the trigger current that injects gate pole by resistance is far smaller than the double silicon control conducting.Bidirectional triode thyristor is in off state, the circuit operate as normal.When supply voltage raises suddenly, and when reaching the magnitude of voltage that needs protection, the trigger current the when electric current by resistance reaches the bidirectional triode thyristor conducting, the bidirectional triode thyristor conducting forms short circuit, and short circuit current fusing protective tube is cut off the electricity supply, and has protected electrical appliance.Simultaneously because the disappearance of bidirectional triode thyristor trigger current.Bidirectional triode thyristor returns to off state, has cut off power supply when short trouble short circuit current fusing protective tube appears in electrical appliance, has guaranteed the work of safety plug normal reliable.

The utility model is owing to adopted bidirectional triode thyristor as over-voltage protection element; not only prolonged the useful life of over-voltage protection element in circuit; and because the bidirectional triode thyristor through-current capacity is big; no-spark during work; safe and reliable; at AC and DC, all can use under the high and low voltage status, widened the scope of application of safety plug greatly.

Protective tube in the utility model adopts socket connection, is convenient to change, and bidirectional triode thyristor, resistance adopt screw to connect or welding, and the installation of plug, use, replacing are very convenient.

Specific embodiment of the utility model is provided by following accompanying drawing:

Fig. 1 is the circuit theory diagrams of utility model

Fig. 2 is an internal structure schematic diagram of the present utility model

As Fig. 1,2:(1) be the electric current protective tube, (2) are bidirectional triode thyristor, and (3) are resistance, and (4) are pin, and (5) are reed, and (6) are terminal screw, and (7) are terminal screw, and (8) are insulating body.Protective tube (1) is plugged on the reed (5), two anodes of bidirectional triode thyristor (2) are attempted by on terminal screw (6), (7), the gate pole of bidirectional triode thyristor is connected on the terminal screw (6) by resistance (3), and the power supply lead wire of load (not drawing among the figure) is connected on respectively on terminal screw (6), (7).Supply voltage just often, the trigger current of bidirectional triode thyristor (2) is less than setting, bidirectional triode thyristor (2) is in off state, power supply by pin (4), protective tube (1), terminal screw (6), (7) to the electrical appliance normal power supply.When supply voltage raises trigger current by gate pole when reaching setting for some reason, bidirectional triode thyristor (2) conducting, short circuit current fusing protective tube (1) is cut off the electricity supply, and has protected electrical appliance.

Claims (1)

1. A kind of safety plug of forming by insulating body (8), pin (4), terminal screw (6) (7); a protective tube (1) is housed in the plug; it is characterized in that in plug, also being equipped with bidirectional triode thyristor (2); resistance (3) is as over-voltage protection element; two anodes of bidirectional triode thyristor (2) are connected on respectively on terminal screw (6) and (7), and the two ends of resistance (3) are connected on respectively on the gate pole and terminal screw (6) of bidirectional triode thyristor (2).