Electrical continuity load monitoring circuit

• US 4,799,019 A
• Filed: 03/02/1987
• Issued: 01/17/1989
• Est. Priority Date: 03/02/1987
• Status: Expired due to Fees

• Current Assignee: Charles E. Cooley, William Fenton Jr
• Original Assignee: Charles E. Cooley, William Fenton Jr
• Inventors: Cooley, Charles, Fenton, William Jr.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Miele, Anthony L.
• Application Number:
  US07/020,873
• Time in Patent Office: 687 Days
• Field of Search: 324/546, 324/511, 324/537, 324/555, 324/556, 324/503, 324/133, 307/632, 361/100
• US Class Current: 324/546
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G01R 31/54 Testing for continuity
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72

Abstract

A load monitoring, indicating, and alarm system monitors electrical continuity through an AC electrical load coupled in a first electrical line with an electrical indicator such as an indicating lamp in a second electrical line coupled in parallel with the first electrical line. A first AC electronic switch such as a triac is coupled in series with the indicator in the second electrical line. The actuating gate of the first AC electronic switch is coupled to the first electrical line. The first AC electronic switch is therefore conducting and the indicator lamp on when there is electrical continuity through the load and power is being supplied to the load. A reactance control component is coupled in series with the load for adjusting the phase angle of gate current to voltage delivered to the gate terminal of the first AC electronic switch. The reactive component may be a second AC electronic switch coupled in series with the electrical load in the first electrical line. A resistor operatively couples the gate terminal of the second AC electronic switch to the second electrical line. A normally closed relay and alarm may be coupled in a third electrical line placed in parallel with the first and second electrical lines for providing an audible alarm or other alarm signal when power is being supplied to the load and there is failure of electrical continuity through the load.

Claims

1. An improved electrical continuity load monitoring circuit for monitoring an AC electrical load coupled in a first electrical line including electrical indicating means in a second electrical line coupled in parallel with the first electrical line and load for monitoring the load comprising:

first AC electronic switch means comprising first and second electrode terminals coupled in series with the indicating means in the second electrical line, said first AC electronic switch means also comprising a gate terminal coupled to the first electrical line for delivering gate current and voltage to the first AC electronic switch means so that the first AC electronic switch means is conducting through the first and second electrode terminals in series with the indicating means when there is electrical continuity through the load and power is being supplied to the load and indicating means thereby actuating the indicator means in the second electrical line for indicating that power is supplied to the load with electrical continuity through the load;

reactance control means coupled in series with the load in the first electrical line for adjusting the phase angle of gate current to voltage delivered to the first electronic switch means for turn on of the first electronic switch means said reactance control means comprising a second AC electronic switch means having first and second electrode terminals coupled in series with the electrical load in the first electrical line and a gate terminal, resistance means operatively coupling the gate terminal to the second electrical line so that the second AC electronic switch means is conducting through the first and second electrode terminals in series with the load when power is being supplied to the load and indicating means and the first electronic switch means is conducting.

2. The load monitoring circuit of claim 1 wherein the first AC electronic switch means comprises a first triac.

3. The load monitoring circuit of claim 1 wherein the first and second AC electronic switch means comprise first and second triacs.

4. The load monitoring circuit of claim 3 wherein the first AC electronic switch means comprises a first triac, the gate terminal of the first triac being coupled to the first electrode terminal of the second triac and the gate terminal of the second triac being coupled to the first electrode terminal of the first triac through said resistance means.

5. The load monitoring circuit of claim 4 wherein the second electrode terminal of the first triac is coupled to the indicating means in the second electrical line and the first electrode terminal of the second triac is coupled to the load in the first electrical line, the first electrode terminal of the first triac being coupled to the second electrode terminal of the second triac for the parallel coupling between the first and second electrical lines.

6. The load monitoring circuit of claim 1 wherein the indicating means comprises resistance light means.

7. An improved electrical continuity load monitoring circuit for monitoring an AC electrical load coupled in a first electrical line including electrical indicating means in a second electrical line coupled in parallel with the first electrical line and load for monitoring the load comprising:

first AC electronic switch means comprising first and second electrode terminals coupled in series with the indicating means in the second electrical line, said first AC electronic switch means also comprising a gate terminal coupled to the first electrical line for delivering gate current and voltage to the first AC electronic switch means so that the first AC electronic switch means is conducting through the first and second electrode terminals in series with the indicating means when there is electrical continuity through the load and power is being supplied to the load and indicating means thereby actuating the indicator means in the second electrical line for indicating that power is supplied to the load with electrical continuity through the load;

reactance control means coupled in series with the load in the first electrical line for adjusting the phase angle of gate current to voltage delivered to the first electronic switch means for turn on of the first

normally closed relay contact means and alarm signal means coupled in series in a third electrical line, said third electrical line and series coupled normally closed relay contact means and alarm signal means being coupled in parallel with the second electrical line and series coupled first AC electronic switch means and indicator means;

and relay armature actuating means for actuating said normally closed relay contact means said relay armature actuating means being coupled in series with the first AC electronic switch means in the second electrical line so that the normally closed relay in the third electrical line is open when power is supplied to the electrical load and indicating means and there is electrical continuity through the load and so that the normally closed relay closes actuating the alarm signal means when there is power being supplied to the load and there is failure of electrical continuity through the load.

8. An improved electrical continuity load monitoring circuit for monitoring an AC electrical load coupled in a first electrical line including electrical indicating means in a second electrical line coupled in parallel with the first electrical line and load for monitoring the load comprising:

first AC electronic switch means comprising first and second electrode terminals coupled in series with the indicating means in the second electrical line, said first AC electronic switch means also comprising a gate terminal coupled to the first electrical line for delivering gate current and voltage to the first AC electronic switch means so that the first AC electronic switch means is conducting through the first and second electrode terminals in series with the indicating means when there is electrical continuity through the load and power is being supplied to the load and indicating means thereby actuating the indicator means in the second electrical line for indicating that power is supplied to the load with electrical continuity through the load;

second AC electronic switch means having first and second electrode terminals coupled in series with the electrical load in the first electrical line and a gate terminal, resistance means operatively coupling the gate terminal to the second electrical line so that the second AC electronic switch means is conducting through the first and second electrode terminals in series with the load when power is being applied to the load and indicating means and the first electronic switch means is conducting, said second AC electronic switch means adjusting the phase angle of current to voltage in the first electrical line for turn on of the first AC electronic switch means; and

said first and second AC electronic switch means being coupled with the gate terminal of the first AC electronic switch means coupled to the first electrode terminal of the second AC electronic switch means in the first electrical line and the gate terminal of the second AC electronic switch means coupled through said resistance means to the first electrode terminal of the first AC electronic switch means in the second electrical line.

9. The load monitoring circuit of claim 8 wherein the second electrode terminal of the first AC electronic switch means is coupled to the indicating means in the second electrical line and the first electrode terminal of the second AC electronic switch means is coupled to the load in the first electrical line, the first electrode terminal of the first AC electronic switch means being coupled to the second electrode terminal of the second AC electronic switch means for the parallel coupling between the first and second electrical lines.

10. The load monitoring circuit of claim 9 wherein the first and second AC electronic switches comprise first and second triacs.

11. The load monitoring circuit of claim 8 wherein the indicator means comprises a resistance light means.

12. The load monitoring circuit of claim 8 further comprising normally closed relay contact means coupled in series with alarm signal means in a third electrical line, said third electrical line and series coupled normally closed relay contact means and alarm signal means being coupled in parallel with the second electrical line and series coupled first AC electronic switch means and indicator means.

13. The load monitoring circuit of claim 12 further comprising relay armature actuating means for actuating said normally closed relay contact means said relay armature actuating means being coupled in series with the first AC electronic switch means in the second electrical line so that the normally closed relay in the third electrical line is opened when power is supplied to the electrical load and indicating means and there is electrical continuity through the load and so that the normally closed relay closes actuating the alarm signal means when there is power being supplied to the load and there is failure of electrical continuity through the load.

14. The load monitoring circuit of claim 13 wherein the indicator means comprises a resistance light means and the alarm means comprises a sound alarm.

15. The load monitoring circuit of claim 13 wherein the relay armature actuating means is coupled in parallel with the indicating means in the second electrical line.

16. The load monitoring circuit of claim 13 wherein the first and second AC electronic switch means comprise first and second triacs.