Alarm circuits to indicate the open status of circuit breakers or fuses for DC telecom and AC distribution circuits

• US 5,233,330 A
• Filed: 11/16/1990
• Issued: 08/03/1993
• Est. Priority Date: 11/15/1990
• Status: Expired due to Fees

• Current Assignee: Alfred M. Hase
• Original Assignee: Alfred M. Hase
• Inventors: Hase, Alfred M.
• Primary Examiner(s): Coles, Sr., Edward L.
• Assistant Examiner(s): Jackson, Jill
• Application Number:
  US07/614,237
• Time in Patent Office: 991 Days
• Field of Search: 340/638, 340/639, 335/17, 361/88, 361/170
• US Class Current: 340/638
• CPC Class Codes: G08B 21/185 Electrical failure alarms

Abstract

An alarm circuit is provided which takes the place of auxiliary contacts that are generally used in association with circuit breakers or fuses to provide an alarm warning in the event that the circuit breaker or fuse in series with a load has opened for any reason. The alarm circuit is provided with a high resistance resistor that is connected to the load end of the circuit breaker, and at the other end of the resistor to a high gain amplifier or solid state switch. The output of the high gain amplifier is connected to a remote signal relay, which may be DC relay or an AC relay. The arrangement is such that the high gain amplifier becomes conductive in the event that the circuit breaker opens, thereby causing an alarm indication. Indicators are associated with the circuits, including an LED to provide a local signal indicative of the fact that the relay has changed its state. A remote alarm circuit is driven by the change of state of the remote signal delay. Because the alarm circuit monitors the circuit breaker itself, a true indication of the fact that the circuit breaker has opened is assured.

Claims

1. An alarm circuit for use in a voltage system having a load across a voltage and in series with a circuit breaker, wherein said alarm circuit is arranged to provide a status or alarm signal when said circuit breaker has opened;

wherein said alarm circuit includes;

a high resistance resistor connected at its first end to the load end of said circuit breaker, and at its second end to the input of a high gain amplifier;

said high gain amplifier having its output connected to a first side of a remote signal relay, a second side of said remote signal relay being connected to one side of said voltage system;

whereby said high gain amplifier is maintained in a non-conductive condition while said circuit breaker remains closed, and is arranged so as to change its state to be substantially fully conductive when said circuit breaker opens;

said remote signal relay being such so as to change its state when said high gain amplifier changes its state to be substantially fully conductive;

and signal means associated with said remote signal relay and arranged so as to give a signal when said remote signal relay changes its state, which signal is indicative of the fact that said circuit breaker has opened;

wherein said second side of said remote signal relay is connected in series connection to a LED and thence to said one side of said voltage system, and said first side of said remote signal relay;

whereby when said circuit breaker opens, said LED and said signal means associated with said remote signal relay will each give a signal indicative of the fact that said circuit breaker has opened;

wherein said voltage system is an alternating current system of which one side is a neutral side, and wherein said remote signal relay and said LED are arranged to be in series with said high gain amplifier, across said voltage system;

wherein said remote signal relay is a direct current relay, and is arranged in series with said LED and said high gain amplifier and the negative end of a first diode;

wherein the positive end of said diode is connected to the side of said voltage system which is remote from said neutral side of said voltage system, and the series connection of said remote signal relay and said LED are connected to said neutral side; and

wherein the side of said load remote from said circuit breaker is also connected to the neutral side of said alternating current system.

2. The alarm circuit of claim 1, wherein said high gain amplifier is a FET.

3. An alarm circuit for use in a voltage system having a load across a voltage and in series with a circuit breaker, wherein said alarm circuit is arranged to provide a status or alarm signal when said circuit breaker has opened;

wherein said alarm circuit includes;

a high resistance resistor connected at its first end to the load end of said circuit breaker, and at its second end to the input of a high gain amplifier;

said high gain amplifier having its output connected to a first side of a remote signal relay, a second side of said remote signal relay being connected to one side of said voltage system;

whereby said high gain amplifier is maintained in a non-conductive condition while said circuit breaker remains closed, and is arranged so as to change its state to be substantially fully conductive when said circuit breaker opens;

said remote signal relay being such so as to change its state when said high gain amplifier changes its state to be substantially fully conductive;

and signal means associated with said remote signal relay and arranged so as to give a signal when said remote signal relay changes its state, which signal is indicative of the fact that said circuit breaker has opened;

wherein said second side of said remote signal relay is connected in series connection to a LED and thence to said one side of said voltage system, and said first side of said remote signal relay;

whereby when said circuit breaker opens, said LED and said signal means associated with said remote signal relay will each give a signal indicative of the fact that said circuit breaker has opened;

wherein said voltage system is an alternating current system of which one side is a neutral side, and wherein said remote signal relay and said LED are arranged to be in series with said high gain amplifier, across said voltage system;

wherein said remote signal relay is a direct current relay, and is arranged in series with said LED and in series with said high gain amplifier;

wherein a first full wave rectifier is connected across said circuit breaker, and said high resistance resistor is connected in series with a first side of the direct current output of said full wave rectifier;

wherein a second full wave rectifier is connected across said voltage system;

wherein said high gain amplifier, said LED, and said remote signal relay are connected in series across said second full wave rectifier;

wherein a second side of said first full wave rectifier which is opposite said first side thereof, and the side of said second full wave rectifier having the same polarity as said second side of said first full wave rectifier are connected together; and

wherein the side of said load remote from said circuit breaker is also connected to the neutral side of said alternating current system.

4. The alarm circuit of claim 3, wherein said high gain amplifier is a FET.

5. An alarm circuit for use in a voltage system having a load across a voltage and in series with a circuit breaker, wherein said alarm circuit is arranged to provide a status or alarm signal when said circuit breaker has opened;

wherein said alarm circuit includes;

a high resistance resistor connected at its first end to the load end of said circuit breaker, and at its second end to the input of a high gain amplifier;

said high gain amplifier having its output connected to a first side of a remote signal relay, a second side of said remote signal relay being connected to one side of said voltage system;

whereby said high gain amplifier is maintained in a non-conductive condition while said circuit breaker remains closed, and is arranged so as to change its state to be substantially fully conductive when said circuit breaker opens;

said remote signal relay being such so as to change its state when said high gain amplifier changes its state to be substantially fully conductive;

and signal means associated with said remote signal relay and arranged so as to give a signal when said remote signal relay changes its state, which signal is indicative of the fact that said circuit breaker has opened;

wherein said second side of said remote signal relay is connected in series connection to a LED and thence to said one side of said voltage system, and said first side of said remote signal relay;

whereby when said circuit breaker opens, said LED and said signal means associated with said remote signal relay will each give a signal indicative of the fact that said circuit breaker has opened;

wherein said voltage system is an alternating current system of which one side is a neutral side, and wherein said remote signal relay and said LED are arranged to be in series with said high gain amplifier, across said voltage system;

wherein a first full wave rectifier is connected across said circuit breaker, and said high resistance resistor is connected in series with a first side of said full wave rectifier;

wherein said remote signal relay is an alternating current relay, and is arranged in series with a second full wave rectifier;

wherein a first side of said second full wave rectifier is connected to a first side of said high gain amplifier and to the side of said first full wave rectifier having the same polarity, said same polarity said being opposite to said first side of said first full wave rectifier to which said high resistance resistor is connected; and

the second side of said second full wave rectifier is connected to said LED, and said LED is connected to a second side of said high gain amplifier;

wherein the side of said load remote from said circuit breaker is connected to the neutral side of said alternating current system; and

wherein the side of said remote signal relay remote from said full wave rectifier is also connected to the neutral side of said alternating current system.

6. The alarm circuit of claim 5, wherein said high gain amplifier is a FET.