Method and apparatus for detecting electrical faults and isolating power source from the electrical faults

• US 6,650,516 B2
• Filed: 02/13/2002
• Issued: 11/18/2003
• Est. Priority Date: 06/26/2000
• Status: Expired due to Fees

• Current Assignee: Premier Aviation, Inc. (Hunt & Palmer Plc)
• Original Assignee: Premier Aviation, Inc. (Hunt & Palmer Plc)
• Inventors: Langford, Joseph Andrew, Osborne, Gregory Warren
• Primary Examiner(s): Leja, Ronald W.
• Application Number:
  US10/076,177
• Publication Number:
  US 20030169544A1
• Time in Patent Office: 643 Days
• Field of Search: 361/42-50, 361/93.1, 361/93.2, 324/512, 324/520-522, 324/525
• US Class Current: 361/42
• CPC Class Codes: H02H 1/0015 Using arc detectors
• CPC Class Codes: H02H 1/04 Arrangements for preventing response to transient abnormal conditions, e.g. to lightning or to short duration over voltage or oscillations; Damping the influence of dc component by short circuits in ac networks
• CPC Class Codes: H02H 3/16 responsive to fault current to earth, frame or mass with balanced or differential arrangement H02H3/26 ; monitoring earth connection H02H5/105

Abstract

The present invention is a method and apparatus for protecting a power supply from electrical faults. The present invention operates substantially independently of the current drawn by the load. In addition, the present invention includes a time delay circuitry for preventing false detection of ground faults when the power source is connecting to the load. In a preferred embodiment, the apparatus of the present invention includes a control circuitry for connecting the power supply to the load. The apparatus also preferably includes a sensor circuitry for detecting electrical faults, including ground, transient, and arc faults, and triggering the control circuitry to disconnect the power source from the electrical faults when electrical faults are detected. Thus, the present invention can protect wiring and load connections from improper operation and fire hazards that may be caused by electrical faults. Finally, the apparatus preferably includes a fault protection condition indicator to indicate whether the circuit breaker circuitry is working properly.

Claims

1. Circuit breaker circuitry, comprising:

(a) control circuitry that connects a power supply to a load, comprising;

a control relay,

a circuit breaker connected to the control relay, and

resistive contacts having a low electrical resistance;

(b) sensor circuitry that detects one or more of transient, arc, and ground faults, comprising;

an optocoupler emitting diode,

an optocoupler detecting diode that detects electromagnetic waves emitted from the optocoupler emitting diode, and

an AND gate that receives a signal from the optocoupler detecting diode as an input;

(c) counting circuitry that determines a count of the one or more transient, arc, and ground faults detected; and

(d) triggering circuitry that triggers the control circuitry to isolate the power supply;

wherein the counting circuitry signals the triggering circuitry when the count exceeds a predetermined number during a preset time interval.

2. The circuit breaker circuitry according to claim 1, wherein the counting circuitry comprises a counter that receives a signal from the sensor circuitry.

3. The circuit breaker circuitry according to claim 2, wherein the counting circuitry further comprises a reset timer that periodically resets the counter.

4. The circuit breaker circuitry according to claim 3, wherein the triggering circuitry comprises a trigger relay that is connected to the counting circuitry.

5. The circuit breaker circuitry according to claim 4, wherein the trigger relay is connected to the circuit breaker.

6. The circuit breaker circuitry according to claim 5, wherein the optocoupler emitting diode is activated by a potential drop across the control relay caused by current drawn by the one or more of transient, arc, and ground faults.

7. The circuit breaker circuitry according to claim 6, wherein the counter increases the count by one when the AND gate outputs a non-zero signal.

8. The circuit breaker circuitry according to claim 7, wherein the counter outputs a high signal when the count exceeds the predetermined number.

9. The circuit breaker circuitry according to claim 8, wherein the trigger relay overloads the circuit breaker when the counter outputs a high signal to the trigger relay.

10. The circuit breaker circuitry according to claim 9, wherein time delay circuitry is connected in series with the sensor circuitry and connected in parallel to the control circuitry.

11. The circuit breaker circuitry according to claim 6, wherein the counter increases the count by one when the AND gate outputs a square wave signal.

12. The circuit ber circuitry according to claim 5, wherein the optocoupler emitting diode is activated by a potential drop across the resistive contacts of the control relay caused by current drawn across the resistive contacts by the one or more of transient, arc, and ground faults.

14. The circuit breaker circuitry according to claim 11, wherein the time delay circuitry further comprises a fault protection indicator diode.

13. Circuit breaker circuitry, comprising:

(a) control circuitry that connects a power supply to a load;

(b) sensor circuitry that detects one or more of transient, arc, and ground faults;

(c) time delay circuitry that shields the sensor circuitry from current spikes generated when the power supply is connecting to the load, wherein the time delay circuitry comprises a time delay relay;

(d) counting circuitry that determines a count of the one or more transient, arc, and ground faults detected; and

(e) triggering circuitry that triggers the control circuitry to isolate the power supply when the count exceeds a predetermined number.