GB2162002A - Circuit breaker with load alarm - Google Patents

Abstract

A circuit breaker such as a no fuse breaker incorporates detectors to detect load condition and displays these with indicators and an alarm to give different warning signals for potential overload and existing overload respectively, so that if the breaker malfunctions its user can be acquainted with the load conditions for adopting appropriate safety measures.

Description

SPECIFICATION Circuit breaker with load alarm This invention relates to a circuit breaker with load alarm, particularly a circuit breaker which has a detector to detect loading condition and can give an alarm if there a potential or existing overload while the breaker malfunctions. This invention is to be mainly used as a safety device for power control switch at family, factory, etc. The current available circuit breakers are of temperature induced no fuse breaker, magnetic induced no fuse breaker, etc. which are designed with self-tripping function which act once their current reaches set value in order to cut off power source.

However, they are not able to prevent from overload, tripping is not possible if breaker malfunctions, and they are not able to foresee overload, wires may fire or other accident may occur due to overload and malfunction of breaker. The inventor designed a circuit breaker with load alarm to eliminate the above defects. The present invention can give different alarms and cut off power source once there is a potential or existing overload to warn forsafety measures.

The present invention has two characteristics: Firstly, it has a detector to detect change of load and it has a control circuit to give a continuous alarm and lights an indicator to indicate load condition if overload is going to occur. Should overload be continued, the alarm may be cancelled through a control switch to prevent from noise. Secondly, it has a detector to detect overload condition and gives a continue alarm and lights an indicator to show load condition if it fails to trip. This alarm sounds different from that warning for potential overload and warns user to adopt safety measures.

An embodiment of a circuit breaker with load alarm according to this invention is described by way of example, with reference to the drawings in which: Fig. 1 is a control circuit block diagram of the embodiment of the present invention; Fig. 2 is a circuit diagram of the embodiment of the present invention; Fig. 3 is a perspective view of the embodiment of the present invention; Fig. 4 is a perspective view (1) of the interior of the embodiment of the present invention; Fig. 5 is another perspective view (2) of the interior of the embodiment of the present invention; Fig. 6 is a fragmental drawing of the embodiment of the present invention; Fig 7 is a fragmental drawing of a singlecontact control of the embodiment; and Fig. 8 is a perspective view for singlecontact assembly of the embodiment.

Fig. 1 is a control circuit block diagram of the embodiment. The power source for the present invention is rectified by a rectifier, transformed by a voltage reducing circuit and then its voltage is stabilized by a voltage stabilizing circuit to its required voltage. Once its detector detects overload of the no fuse breaker, and if the no fuse breaker malfunctions which disables tripping of power contacts, its display circuit causes lighting of an indicator and its alarm circuit is energized for giving a continuous warning signal or buzz different from that of potential overload in order to remind its user to adopt safety measures.

Fig. 2 is a circuit diagram of the embodiment. S, and S2 are Detection Switches 1 and 2 respectively. That is, S, is for detecting potential overload condition and S2 is for existing overload. S3 is an alarm switch for alarm waring potential overload condition TR and TR2 are oscillating transistors which can oscillate in conjunction with R4, R5, R6, C2 and C3 so that if the detection swtich S1 is ON, the oscillation circuit oscillate to energize the speaker SP, to give a continuous alarm, and if the detection switch S2 is ON, the oscillation circuit oscillates to energize the speaker SP2 to give a continuous alarm.

Fig. 3 is a perspective view of the embodiment. There is a test key (4), a warning indicator (41) and an overload indicator (42) on the top of its housing (1). After turning on its control switch (11), pressing the test key (4) can cause self-tripping of the control switch (11) and cutting off its power source for function testing of the breaker. The yellow warning indicator (41) will light if there is a potential overload. If current passing the breaker is increasing, overload occurs but the breaker fails to trip by itself, the red overload indicator (42) light so that its user can know the loading condition of the breaker for adopting necessary safety measures.

Fig. 4 is a perspective view (1) of the interior of the mebodiment. Fig. 5 illustrates another perspective view (2) of its interior.

The control switch (11) on the housing (1) is for turning on and off the breaker. There are three overload detectors (12), (12') and (12") within the housing (1). The said overload detectors (12), (12'), and (12") generate magnetic force proportional to the passing current. Once the passing current is going to cause overload, the said overload detectors (12), (12') and (12") generate a sufficient magnetic force to pull a control plate (1 3) to a preset position so that an end (131) of the control plate (14) can push a control rod (14), move it leftwards to a preset position till it contacts a detecting spring plate (16) and causes the first detecting spring plate (1 6) to touch the second detecting spring plate (16') for forming a close circuit between the power source and the second detecting spring plate (16').Once the overload detectors (12), (12') and (12") detect an overcurrent, they can generate a sufficient magnetic force to attract the control plate (13), (13') and (13") so that the end (131) of the control plates can push the control rod (14) to its left extremity and cause all the detecting spring plates (16), (16') and (16"0 to connect with the power source. Simultaneously, a control member (17) at the inner side of the mouting bracket moves upwards slightly so that a control element (18) below the control member (17) can be released from the binding of the latter for rightward tripping and cutting off the power source, i.e., the power switch is turned off.In case the control member (17) and the control element malfunction (i.e., malfunction of the conventional no fuse breaker which may cause wire burning, the power source can't be turned off, the detecting spring plates (16), (16') and (16") detect a malfunction signal and cause a continuous alarm to warn its user for appropriate safety measures.

The Fig. 6 is a fragmental drawing of the embodiment wherein the speaker (2) is a small speaker located on a recession (1 91) on the base (19). The base can cause a resonance to give a loud alarm. The said speaker may be installed outside the breaker too.

The Fig. 7 is a fragmental drawing of a single-contact control of the embodiment. The Fig. 8 is a fragmental drawing of a singlecontact assembly of the embodiment. There is a control switch (31) on its housing (3). A control arm (32) and a moveable plate (33) are installed below the control switch (31).

The control arm (32) is laying across an opening (341) of a L-like control plate (34).

Once the control swtich (31) is turned, the control arm (32) which supports the L-like control plate (34) which, with the control arm (32) as a pivot, causes the moveable plate for rightward and leftward movement. Thus, a metal plate (35) control turning on and off of its power source according to the movment of the moveable plate (33). There is a special metal plate (36) within the housing. Once current is passing the special metal plate (36).

The special metal plate expands in proprtional to its temperature. Since the special metal plate (36) is fixed at its upper end, expansion of it will cause downward extension. If over current occurs, the special metal plate (36) causes the L-like control plate (34) to fall downwards so that the control arm leaves the opening (341) of the L-like control plate (34), i.e., tripping of the breaker to cut off power source.

Whenever the special metal plate (36) touches the L-like control plate (34) for tripping, the special metal plate (36) touches the detecting spring plate (37). Thus, the first detecting spring plate (37) contacts with the second detecting spring plate (37') so that there is a current passing the first detecting spring plate (37) and a close circuit is formed from the power source, through the metal plate (35), wire (38), the first detecting spring plate (37) and the second detecting spring plate (37'). The special metal plate (36) of the present invention has an insulated lower end, or the upper end of the first detecting spring plate (37) is insulated, or an insulating pad (39) is used to prevent from the current to pass the first detecting spring plate (37) through the special metal plate (36) when the special metal plate (36) is contacting with the first detecting spring plate (37). A close circuit is formed when the first detecting spring plate (37) keeps contacting with the second detecting spring plate (37'), i.e., a circut composing the switch S2 as shown in the Fig. 2. When the present invention is using a single contact control switch, as shown in the Fig. 8, two metal plates (35) and (35') connecting to the respective poles of a power source are used for the contol.

The detecting spring plate in the above embodiment may be replaced with infrared detector, or temperature detector, or magnetic detector, if required.

Claims (4)

1. A circuit breaker with load alarm which is characterized by incorporation of detecting spring plates and alarm system in a circuit breaker which can cut off power source and give different alarms for potential overload and existing overload if the circuit breaker fails to trip off by itself so that its user can be acquainted with the load condition of the breaker in order to avoid firing of wire or other accidents.

2. A circuit breaker with load alarm as claimed in the Calim 1 wherein the said detecting spring plates can be replaced with intrared detector, or temperature detector, or current detector incorporating with an alarm system to give different warnings for potential overload and existing overload.

3. A circuit breaker with load alarm as claimed in the Claim 1 wherein the alarm system is comprising oscillation circuit, display circuit, speaker, etc. so that once the detecting spring plates detect an overload signal, the display show overload condition with its indicators and the oscillation circuit can energize the speaker to give different alarms for different overload conditions.

4. A circuit breaker with load alarm constructed and arranged substantially as herein described with reference to any of the drawings.