CN2407490Y

CN2407490Y - Under-voltage releaser

Info

Publication number: CN2407490Y
Application number: CN 99255613
Authority: CN
Inventors: 郎建才
Original assignee: BEIJING SWITCH FACTORY
Current assignee: BEIJING SWITCH FACTORY
Priority date: 1999-12-09
Filing date: 1999-12-09
Publication date: 2000-11-22
Anticipated expiration: 2009-12-09

Abstract

The utility model provides an under-voltage release for a circuit breaker, which has the advantage that after the circuit breaker is switched off, the circuit breaker can be immediately switched on again, comprising a trip coil and a moving iron core, wherein, power is supplied for the trip coil by a rectification circuit, the moving iron core is attracted by the trip coil, and thus, a trip shaft is driven to move. The utility model is characterized in that the utility model is provided with a normally closed contact (S1) driven by the moving iron core (1); the trip coil (L) is formed by the connection in series of two coils (L1), (L2) which are wound on the same framework, wherein, the number of turns of a coil (L1) is more than the number of turns of the other coil (L2), and the wire size of a coil is thinner than that of the other coil; the normally closed contact (S1) is connected with the coil (L1) in parallel.

Description

Under-voltage release

The utility model relates to under-voltage release, especially for the under-voltage release that plays the under voltage protection effect in the circuit breaker.

As the circuit breaker with under-voltage release, when it was in gate-dividing state, the moving iron core of under-voltage release contacted with trip shaft, therefore, before the breaker closing, under-voltage release should make it to separate with trip shaft by the moving iron core of first adhesive, thereby allows breaker closing.Under the normal working voltage, the moving iron core of under-voltage release is in attracting state always.In the time of in the operating voltage of circuit breaker is reduced to a certain prescribed limit, under-voltage release should move, and discharge moving iron core and make it to touch trip shaft, thereby with breaker open operation; And when supply voltage returns to greater than a certain setting, should guarantee that circuit breaker can close a floodgate, promptly the moving iron core of under-voltage release should separate with trip shaft.

Existing a kind of under-voltage release that is used for circuit breaker as shown in Figure 4.This under-voltage release has tripping coil L ', be subjected to the L ' adhesive of this tripping coil and drive the trip shaft action moving unshakable in one's determination 1 ', the power supply alternating current is become direct current supply with the rectification circuit Z ' of said tripping coil L ', be connected in the thermistor Rt between power supply E ' and the rectification circuit Z '.

The operation principle of above-mentioned existing under-voltage release is as described below.

When the normal power supply of voltage is connected at first, thermistor Rt is in cold conditions thereby resistance is less, rectification circuit Z ' provides big electric current to tripping coil L ', thereby produce big electromagnetic attraction, 1 ' the below of active force in Fig. 4 (b) that overcomes spring 7 ' unshakable in one's determination moved and break away from the not shown trip shaft that is positioned at its top and with fixed core 9 ' adhesive, thereby allow breaker closing; Along with current flowing, thermistor Rt heating, its resistance increases, and makes power supply less to the electric current that tripping coil L ' provides, and the electromagnetic attraction that this small electric miscarriage is given birth to is enough to overcome the spring force of spring 7 ' to keep moving unshakable in one's determination 1 ' attracting state.

When owing to reasons such as supply voltage reductions; when too small the thereby electromagnetic attraction of the electric current of circulation is too small in the coil L '; moving iron core 1 ' will move in the top in Fig. 4 (b) under the effect of spring 7 ' and touch the not shown trip shaft that is positioned at its top, with breaker open operation, realize under voltage protection.

As mentioned above, this under-voltage release is in the process of normal operation of circuit breaker, and thermistor Rt is in hot always.Therefore, its maximum shortcoming is behind the breaker open operation, can not close a floodgate immediately.Promptly, behind the separating brake, because the hot of thermistor Rt will keep a period of time, during this period of time its resistance is bigger, therefore, even supply voltage is normal, also can only provide less electric current to tripping coil L ', tripping coil L ' can not produce enough big electromagnetic attraction adhesive moving unshakable in one's determination 1 ' and make it to break away from trip shaft, so circuit breaker can't close a floodgate.

The purpose of this utility model is, a kind of that close a floodgate, that be used for circuit breaker once more immediately under-voltage release behind the breaker open operation that makes is provided.

For achieving the above object, the under-voltage release that is used for circuit breaker of the utility model claim 1, have by the tripping coil of rectification circuit power supply, be subjected to this tripping coil adhesive and drive the moving iron core of trip shaft action, it is characterized in that also having by the persuade normally closed contact that drives unshakable in one's determination; Said tripping coil is in series by two coils that are wound on the same skeleton, and wherein, coil is many and the line footpath is thin than the number of turn of another coil, and the many and line of said normally closed contact and the said number of turn directly thin coil is in parallel.

The under-voltage release that is used for circuit breaker of the utility model claim 2 is characterized in that, also has the current-limiting resistance that is connected in series with the thin coil in the multi-thread footpath of the said number of turn, and said normally closed contact and the said coil that is connected in series, current-limiting resistance are in parallel.

The under-voltage release that is used for circuit breaker of the utility model claim 3 is characterized in that, said rectification circuit is to be made of integrated rectification circuit.

The under-voltage release that is used for circuit breaker of the utility model claim 4 is characterized in that, said two coils inside and outside setting the on this skeleton that is wound on the same skeleton.

The under-voltage release that is used for circuit breaker of the utility model claim 5 is characterized in that, is connected with piezo-resistance on the input of said rectification circuit.

Fig. 1 (a) is the electrical schematic diagram of an embodiment of the utility model under-voltage release, (b) is the assembling schematic diagram of this embodiment.

Fig. 2 is the electrical schematic diagram of another embodiment of the utility model under-voltage release.

Fig. 3 is the assembling schematic diagram of another embodiment of the utility model under-voltage release.

Fig. 4 (a) is the electrical schematic diagram of the thermosensitive resistance type under-voltage release of prior art, (b) is the assembling schematic diagram of this existing under-voltage release.

Below, in conjunction with the accompanying drawings the related under-voltage release that is used for circuit breaker of the utility model is described in detail.

Fig. 1 (a) and Fig. 1 (b) are respectively electrical schematic diagram and the assembling schematic diagrames of an embodiment of the utility model under-voltage release.Fig. 1 (b) illustrates the initial condition that the present embodiment under-voltage release is in moving 1 release unshakable in one's determination, normally closed contact S1 closure.

As shown in Figure 1, but the utility model under-voltage release also has the normally closed contact S1 by above-mentioned moving 1 switch driven element unshakable in one's determination except tripping coil L with the moving L unshakable in one's determination of adhesive and supply with to said tripping coil L the rectification circuit Z of direct current.Said tripping coil L is in series by the footpath of the line on same skeleton two coil L1, L2 different, that the number of turn is different, and for example in the present embodiment, L2 compares with coil, and the number of turn of coil L1 is more and the line footpath is thinner.Be parallel with said normally closed contact S1 on the thinner coil L1 in the more multi-thread footpath of the said number of turn, when this normally closed contact S1 is closed, can be with coil L1 short circuit.Said rectification circuit Z is made of commercially available integrated rectification circuit.

Below, the operation principle of the utility model under-voltage release the foregoing description is described as follows.

Under the initial condition shown in Fig. 1 (b), although the air gap between moving iron core 1 and the fixed core 9 is bigger, but because the normally closed contact S of switch element that is in closure state is with coil L1 short circuit, so only with the load of the thick coil L2 that the number of turn is less thereby resistance is less in said line footpath as rectification circuit Z, therefore, pass through big electric current in the coil L2, produce big electromagnetic attraction, 1 below of active force in Fig. 1 (b) that overcomes spring 7 unshakable in one's determination moved and fixed core 9 adhesives, this moving iron core 1, break away from this trip shaft with the contacted position of not shown trip shaft that for example is positioned at its top, thereby allow breaker closing; Simultaneously, contact the switch element that for example is located at its below with moving unshakable in one's determination 1 of fixed core 9 adhesives and make it normally closed contact S1 disconnection, make coil L1 be serially connected in rectification circuit Z output with coil L2, therefore, tripping coil L absorbs less electric current to rectification circuit Z, but the electromagnetic attraction that this less electric current produced is enough to overcome the spring force of spring 7 to keep moving unshakable in one's determination 1 attracting state.

Under the normal situation of supply voltage, said normally closed contact S1 will be in off-state always.Therefore; in supply voltage is reduced to the assigned voltage scope; thereby when the electric current that flows through said coil L1 and coil L2 reduces the electromagnetic attraction that produced less than the spring force of spring 7; moving unshakable in one's determination 1 will move in the top in Fig. 1 (b) under the effect of spring 7 spring forces and touch the not shown trip shaft that for example is positioned at its top; with breaker open operation, realize under voltage protection.

Behind the breaker open operation, normally closed contact S1 recovers closure state, has only the thick thereby less coil L2 of resistance in the less line of said number of turn footpath as the load of rectification circuit Z, therefore, as long as it is normal that supply voltage recovers, can adhesive moving unshakable in one's determination 1 make it to break away from trip shaft, allow breaker closing.

Therefore, according to the embodiment of Fig. 1, can obtain to make that close a floodgate, that be used for circuit breaker once more immediately under-voltage release behind the breaker open operation.

The formation of the utility model under-voltage release is not limited to embodiment illustrated in fig. 1, can also carry out various changes.For example,

1. in the embodiment shown in fig. 1, also can increase a current-limiting resistance R who connects with said coil L1, and be parallel with said normally closed contact S1 (shown in the embodiment of Fig. 2) on the coil L1 of this series connection, the current-limiting resistance R.As previously mentioned, after the tripping coil L adhesive moving unshakable in one's determination 1, as long as there is less current can keep persuade unshakable in one's determination 1 adhesive, why the coil L1 of said tripping coil L makes the thin thereby bigger coil of resistance in the multi-thread footpath of the number of turn, and one of its reason is exactly in order to play metering function.If play metering function jointly with the said coil L1 current-limiting resistance R that is connected in series, then can reduce the resistance of this coil L1, promptly reduce the number of turn of this coil L1, thereby help reducing the volume of said coil L1, thereby can reduce the utility model under-voltage release overall volume.

2. in embodiment illustrated in fig. 1, two coil L1, the L2 of said tripping coil L are inside and outside the setting on same skeleton.But also can be shown in the embodiment of Fig. 3, with said two coil L1, L2 upper and lower settings, during upper and lower settings, these two coil L1, L2 also can not be wound on the same skeleton and be wound on respectively on separately the skeleton.

3. in embodiment illustrated in fig. 1, said rectification circuit Z is made of commercially available integrated rectification circuit, helps improving circuit reliability.Obviously, also can be with common discrete device formation such as rectifier diode for example.

4. in embodiment illustrated in fig. 1, said tripping coil L is connected on the dc output end of rectification circuit Z, and promptly said tripping coil L is driven by DC power supply.But said tripping coil L also can make the coil of AC driving, and promptly said tripping coil L also can directly be connected ac power input end.At this moment, can omit rectification circuit Z, can either reduce the volume of wiring board, can also reduce cost.

5. also can be shown in the embodiment of Fig. 2, piezo-resistance Rv in parallel on the input of said rectification circuit Z so that this rectification circuit Z is played the overvoltage protection effect, improves the reliability of rectification circuit Z.

Claims

1. under-voltage release that is used for circuit breaker has by the tripping coil of rectification circuit power supply, is subjected to this tripping coil adhesive and drives the moving iron core of trip shaft action, it is characterized in that,

Also has the normally closed contact (S1) that drives by persuading iron core (1);

Said tripping coil (L) is in series by two coils (L1), (L2) that are wound on the same skeleton, and wherein, a coil (L1) is many and the line footpath is thin than the number of turn of another coil (L2),

Said normally closed contact (S1) is in parallel with said coil (L1).

2. the under-voltage release that is used for circuit breaker as claimed in claim 1, it is characterized in that, also have the current-limiting resistance (R) that is connected in series with the thin coil (L1) in the multi-thread footpath of the said number of turn, said normally closed contact (S1) is in parallel with the said coil that is connected in series (L1), current-limiting resistance (R).

3. as the under-voltage release that is used for circuit breaker of claim 1 or 2, it is characterized in that said rectification circuit (Z) is to be made of integrated rectification circuit.

4. as the under-voltage release that is used for circuit breaker of claim 1 or 2 or 3, it is characterized in that said two coils (L1), (L2) inside and outside setting on this skeleton that is wound on the same skeleton.

5. as the under-voltage release that is used for circuit breaker of claim 1 or 2 or 3 or 4, it is characterized in that, on the ac input end of said rectification circuit (Z), be connected with piezo-resistance (Rv).