Two terminal arc suppressor

• US 9,087,653 B2
• Filed: 11/20/2013
• Issued: 07/21/2015
• Est. Priority Date: 03/12/2010
• Status: Active Grant

• Current Assignee: ARC Suppression Technologies, LLC
• Original Assignee: ARC Suppression Technologies, LLC
• Inventors: Henke, Reinhold
• Primary Examiner(s): Jackson, Stephen W
• Application Number:
  US14/085,438
• Publication Number:
  US 20140078623A1
• Time in Patent Office: 608 Days
• Field of Search: 361/2
• US Class Current: 1/1
• CPC Class Codes: H01H 89/00 Combinations of two or more different basic types of electric switches, relays, selectors and emergency protective devices, not covered by any single one of the other main groups of this subclass
• CPC Class Codes: H01H 9/30 Means for extinguishing or preventing arc between current-carrying parts
• CPC Class Codes: H01H 9/542 Contacts shunted by static switch means
• CPC Class Codes: H01H 9/547 Combinations of mechanical switches and static switches, the latter being controlled by the former

Abstract

A two terminal arc suppressor for protecting switch, relay or contactor contacts and the like comprises a two terminal module adapted to be attached in parallel with the contacts to be protected and including a circuit for deriving an operating voltage upon the transitioning of the switch, relay or contactor contacts from a closed to an open disposition, the power being rectified and the resulting DC signal used to trigger a power triac switch via an optoisolator circuit whereby arc suppression pulses are generated for short predetermined intervals only at a transition of the mechanical switch, relay or contactor contacts from an closed to an open transition and, again, at an open to a close transition during contact bounce conditions.

Claims

1. An AC arc suppressor, comprising:

(a) a pair of terminals adapted to be connected across a set of switchable contacts, the set of switchable contacts configured to couple an AC voltage source to a load;

(b) a solid state triggerable switch connected between the pair of terminals;

(c) a triggering circuit operatively coupled to the solid state triggerable switch operative upon the switchable contacts moving from a closed state to an open state for driving the solid state triggerable switch into a conductive state to short out the switchable contacts; and

(d) a pinch-off circuit coupled to the triggering circuit for controlling the length of time that the solid state triggerable switch remains in said conductive state following movement of the switchable contacts from the closed state to the open state.

2. The arc suppressor of claim 1 and further including a voltage surge limiting component connected between the pair of terminals.

3. The arc suppressor of claim 2 wherein the component is a metal oxide varistor.

4. The arc suppressor of claim 2 wherein the component is a transient voltage suppressor.

5. The arc suppressor of claim 1 wherein the solid state triggerable switch comprises a full wave rectifier bridge having input terminals connected to said pair of terminals and a transistor switch connected across output terminals of the rectifier bridge.

6. The arc suppressor of claim 5 wherein said triggering circuit comprises an optoisolator having an input IR emitter source and output IR detectors, said input IR emitter source connected in series with a resistor and a connector between said pair of terminals and the IR detector connected to the transistor switch.

7. The arc suppressor of claim 1 wherein the solid state triggerable switch comprises a power triac having a first anode electrode connected to one of the pair of terminals, a second anode electrode connected to the other of the pair of terminals and a triggering electrode.

8. The arc suppressor of claim 7 wherein the triggering circuit comprises an optoisolator having an input IR emitter source and an output IR detector, said output IR detector being connected to said triggering electrode.

9. The arc suppressor of claim 8 wherein the triggering circuit further includes a full wave rectifier connected between said pair of terminals and having output terminals connected to the input IR emitter source of the optoisolator.

10. The arc suppressor of claim 8 wherein the pinch-off circuit comprises a transistor having a collector electrode connected to one terminal of the input IR emitter source, an emitter electrode connected to a second terminal of the input IR emitter source and a base electrode connected by an RC timing circuit to a contact power harvester circuit.

11. The arc suppressor of claim 10 wherein the contact power harvester circuit comprises a full-wave rectifier connected through a coupling capacitor to a first of the pair of terminals and connected through a current limiting resistor to a second of the pair of terminals, and DC output terminals of the full-wave rectifier connected to the RC timing circuit.

12. A solid state, two terminal AC arc suppressor comprising:

(a) a pair of terminals adapted to be connected across switchable contacts configured to couple an AC voltage source to a load;

(b) a contact power harvester circuit connected between the pair of terminals for producing a DC voltage upon the switchable contacts transitioning from a closed state to an open state;

(c) a power triac circuit having a first anode electrode connected to one of the pair of terminals, a second anode electrode connected to the other of the pair of terminals and a triggering electrode; and

(d) circuit means connected to the contact power harvester circuit and the triggering electrode for driving the power triac circuit into a conducting state only for a predetermined time interval when the switchable contacts transition from an open state to a closed state and for again rendering the power triac circuit conducting for only a predetermined time interval when the switchable contacts transition from a closed state to an open state.

13. The arc suppressor of claim 12, wherein the circuit means comprises an optoisolator having an IR emitter source and an IR detector wherein the IR detector is connected in driving relation to the triggering electrode and the IR emitter source is connected to a source of DC current.

14. The arc suppressor of claim 13 wherein the source of DC current is a full-wave rectifier coupled to the pair of terminals.

15. The arc suppressor of claim 14 and further including a pinch-off circuit coupled to the IR emitter source for turning off the IR emitter source at a predetermined time following the transition of the switchable contacts from the open state to the closed state and from the closed state to the open state.

16. The arc suppressor of claim 15 wherein the pinch-off circuit includes a semiconductor switch connected across DC output terminals of the full-wave rectifier.

17. The arc suppressor of claim 16 and further including a RC timing circuit coupled to the semiconductor switch for turning on the semiconductor switch a predetermined time following said transitioning.

18. The arc suppressor of claim 17 wherein the predetermined time is within a range of from 0.1 ms to 10 ms.

19. A solid state, two terminal AC arc suppressor comprising:

(a) a first pair of input terminals adapted to be connected in parallel relation to a set of switchable contacts configured to couple an AC voltage source to a load,

(b) a surge suppressor component connected between the first pair of input terminals;

(c) a snubber circuit comprising a resistor and a capacitor connected in series between the first pair of input terminals;

(d) a triggerable solid state switching device connected between the first pair of input terminals; and

(e) a triggering circuit for driving the triggerable solid-state switch into a conducting state for a predetermined time interval upon the making or the breaking of the set of switchable contacts.

20. The arc suppressor of claim 19, wherein the triggerable solid state switching device comprises a full-wave rectifier bridge having a second pair of input terminals connected individually to the first pair of input terminals and a pair of output terminals with a transistor switch having a collector to emitter path connected to the pair of output terminals;

and

said triggering circuit including an optoisolator having an IR emitter source connected in series with a resistor and a capacitor between the first pair of input terminals and an IR detector connected in driving relation to a base electrode of the transistor switch.