Non-arc power-off protection switch control circuit

A switch control circuit and power-off protection technology, which is applied in the field of electric switches, can solve the problems of long-time power-on of control circuits, reduced service life, and long working hours, so as to protect bidirectional thyristors, prolong service life, and prevent instantaneous current impact effect

CN104811169AActive Publication Date: 2015-07-29KEDU ELECTRIC CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2015-07-29

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Abstract

The invention discloses a non-arc power-off protection switch control circuit. The control circuit comprises a first switch, a second switch, a first time delay circuit, a first controllable switch, a second controllable switch, a second time delay circuit and a thyristor circuit, wherein one end of the first switch is connected to a live wire of a power supply, and the other end of the first switch is connected with a load; the first time delay circuit is used for rectifying output of the power supply and controlling on and off of the second controllable switch; the second time delay circuit is used for controlling on and off of the first controllable switch; the time constant of the second time delay circuit is smaller than the time constant of the first time delay circuit; the second switch is connected between a second input end of the second time delay circuit and a null wire; the thyristor circuit is in circuit connection between the live wire of the power supply and the load. The non-arc power-off protection switch control circuit has the characteristics of long life, simple structure and low cost.
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Description

technical field

[0001] The invention belongs to the field of electric switches, and in particular relates to a control circuit for a non-arc power failure protection switch. Background technique

[0002] At present, AC contactors generally use capacitors connected in parallel in the line as power factor compensation. This type of AC contactor has arcing and high surge current, and the compensation circuit is easy to break down, the service life is short, and the long-term operation cost is high.

[0003] Thyristor capacitor switching switch has the advantages of no surge when connecting the capacitor and no arc when breaking the capacitor. However, due to the problems of large conduction voltage drop, temperature rise, and large harmonic pollution, it has appeared on the market for this reason. A capacitive switching switch called a compound switch with a parallel structure of a thyristor and a mechanical contact has been introduced. It has the advantages of reduced voltage ...

Examples

Embodiment Construction

[0034] Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the terms "first", "second", "third", etc. herein, if present, are used to distinguish between similar elements and do not necessarily describe a particular order or chronological order order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the subject matter described herein are, for example, capable of being performed in an order different from that described herein or in another order described herein. operate. The term "connected" is to be interpreted broadly and refers to electrically, mechanically, or otherwise connecting two or more elements or signals, either directly or indirectly through intermediate circuits and / or elements.

[0035] figure 2 Shows the structural block diagram of the non-arc cut-off protection switch control circuit of the embodiment of the prese...