CN102497186A

CN102497186A - Realization method of direct current load switch

Info

Publication number: CN102497186A
Application number: CN2011104401394A
Authority: CN
Inventors: 张腾
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-12-26
Filing date: 2011-12-26
Publication date: 2012-06-13

Abstract

The invention relates to a direct current load switch that is formed by parallel connection of a noncontact electronic switch and a contact mechanical switch. The noncontact electronic switch is concretely responsible for tasks of direct current circuit connection and disconnection; and the contact mechanical switch is not responsible for the tasks of direct current circuit connection and disconnection but for bearing a direct current working current after the connection; and the two switches that are in parallel connection take asynchronous actions. During the connection process, the electronic switch is firstly connected; and then the mechanical switch is connected only on the condition that the mechanical switch bears conduction pressure drop of the electronic switch and a normal working current. During the disconnection process, the mechanical switch is firstly disconnected under the circumstances that the conduction pressure drop of the electronic switch is born; and all working currents are transferred to the electronic switch and then the electronic switch is disconnected. According to the direct current load switch provided in the invention, a corresponding blow-out circuit to be omitted; and the direct current load switch not only can be used as an ordinary control switch but also can be directly arranged at a terminal load supply power line and be used as a safe switch.

Description

A kind of implementation method of dc load switch

Technical field the present invention relates to a kind of dc load switch.

When background technology connection, disjunction DC circuit, the direct-current arc of generation is difficult for extinguishing.Now widely-used dc circuit breaker because complicated direct-current arc arc-control device is contained in its inside, causes volume big as control, the protection device of DC circuit, and cost is high, and when controlling the low capacity dc load, cost performance is not high.

Summary of the invention task of the present invention provides the dc load switch that a kind of volume is little, cost is low, both can be used as general control switch and has used, and also can be set directly on the load power supply line of terminal, uses as safety switch.

A kind of dc load switch: by contactless electronic switch with have the mechanical switch of contact to be formed in parallel.

Said contactless electronic switch (hereinafter to be referred as electronic switch) is specifically responsible for DC circuit and is connected and the disjunction task.

The said mechanical switch (hereinafter to be referred as mechanical switch) that the contact is arranged, the connection of not responsible DC circuit and disjunction task only are responsible for carrying the working direct current after connecting.

When this dc load switch was in the disjunction state, electronic switch and mechanical switch all were in off-state; In the connection process, electronic switch is at first connected, and mechanical switch is only bearing connection again under electronic switch conduction voltage drop and the running current then; Under stable on-state, electronic switch and mechanical switch all are in on-state, and operating current is mainly held by mechanical switch and plants; Mechanical switch is at first bearing disconnection under the conduction voltage drop of electronic switch in breaking course, and operating current is all transferred to electronic switch, and electronic switch breaks off again then.

Independently electronic switch also can be accomplished connection, the carrying of above-mentioned on-load switch, the task of disjunction running current, as a kind of on-load switch, though not responsible disjunction fault current will carry fault current.Because as the controllable semiconductor device that electronic switch uses, thermal capacity is little, burns electronic switch for preventing serious Short-Circuit High Current, from the reliability angle, has designed the big mechanical switch of parallelly connected thermal capacity.

The mechanical switch that the present invention utilizes contactless electronic switch to be parallel with the contact constitutes the hardware components of dc load switch; The asynchronous behavior of two kinds of switches of parallel connection; Making has the contact mechanical switch only bearing the conduction voltage drop of electronic switch---connection, disjunction under this micro voltage; Changed the condition that has the contact mechanical switch when connection, disjunction DC circuit, to produce electric arc separately; Reduce and even eliminated direct-current arc, thereby can dispense corresponding arc-suppression circuit, accomplished that design volume is little, cost is low, the invention task of the dc load switch of reliable operation.

Hereinafter combines accompanying drawing and embodiment that the present invention is further described.

Fig. 1 is the fundamental diagram of dc load switch.

Fig. 2 is a kind of concrete realization circuit diagram of dc load switch.

Embodiment Fig. 2 has provided a kind of concrete realization circuit of dc load switch.Field-effect transistor K1 constitutes the main body of contactless electronic beam switch, and resistance R 1 provides the grid-control voltage of K1, and voltage-stabiliser tube Z1 provides protection to the grid-control voltage of K1, and the state of contact mechanical switch K3 control K1 is arranged; The contact mechanical switch that has of parallel connection is made up of K2.

When this dc load switch is in the disjunction state: K3 close with, K1 grid-control voltage be zero, K1 breaks off, K2 breaks off, the dc load switch breaks off.

The connection process of this dc load switch is: at first break off K3; For K1 provides grid-control voltage, voltage-stabiliser tube Z1 guarantees the K1 grid-control voltage in safe range to DC input voitage Vi through resistance R 1, treat that grid-control voltage is set up after; The K1 conducting, output voltage V o sets up.Owing between mechanical switch K3, the K2 interaction relation is arranged, can only change the process need level second time of manual operation mechanical switch by the logic of break-before-make; And the service time of metal-oxide-semiconductor K1 is the microsecond level; Therefore, the manual operation mechanical switch is to K2 when closed, electronic switch K1 conducting fully; The big stream surge process of DC circuit conducting moment finishes, and makes K2 only closed under the conduction voltage drop that bears running current, electronic switch.

When this dc load switch was in conducting state, K3 broke off, the K1 conducting, and K2 is closed.Conducting resistance when artificially the conducting resistance of selection metal-oxide-semiconductor K1 is greater than the K2 closure, the working direct current overwhelming majority is born by mechanical switch K2.

The breaking course of this dc load switch is: mechanical switch K2 is at first broken off in manual operation; Mechanical switch K2 is only bearing disconnection fully under the conduction voltage drop of K1; Operating current is all transferred to electronic switch K1, and along with manually-operated process development, mechanical switch K3 is closed; Electronic switch K1 loses grid-control voltage and ends, and the dc load switch is in off-state.

Claims

1. the implementation method of a dc load switch: by contactless electronic switch (hereinafter to be referred as electronic switch) with there is the mechanical switch (hereinafter to be referred as mechanical switch) of contact to be formed in parallel, it is characterized in that:

Electronic switch K1 is specifically responsible for DC circuit and connects and the disjunction task, and the connection of the not responsible DC circuit of mechanical switch K2 and disjunction task only are responsible for carrying the working direct current after connecting; Two kinds of switch asynchronous behaviors of parallel connection; When this dc load switch was in the disjunction state, electronic switch K1 and mechanical switch K2 all were in off-state, in dc load switch connection process; Electronic switch K1 at first connects; Mechanical switch K2 only connects bearing under electronic switch K1 conduction voltage drop and the running current more then, and under the stable on-state of dc load switch, electronic switch K1 and mechanical switch K2 all are in on-state; In dc load switch breaking course; Mechanical switch K2 at first breaks off under the conduction voltage drop that bears electronic switch K1, and operating current is all transferred to electronic switch K1, and electronic switch K1 breaks off again then.

2. dc load switch according to claim 1 is characterized in that:

The conducting resistance of electronic switch K1 is the conducting resistance when closed greater than mechanical switch K2, and the working direct current overwhelming majority is carried by mechanical switch K2 under the conducting state.