Electrical contactor

Patent metadata

Field	Value
Publication number	US-9607780-B2
Application number	US-201414554470-A
Country	US
Kind code	B2
Filing date	Nov 26, 2014
Priority date	Nov 26, 2013
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

An electrical contactor for switching a load current having an AC waveform, has a fixed electrical contact, a movable electrical contact, an actuator arrangement having a drive coil drivable for opening and closing the movable and fixed electrical contacts, and a power supply having a controller for outputting truncated-waveform drive pulses to the electrical actuator arrangement, so as to prevent contact separation prior to peak load current.

First claim

The invention claimed is:

1. An electrical contactor comprising: a fixed electrical contact, a movable electrical contact, an AC dual-coil actuator having a drive coil drivable for opening and closing the movable and fixed electrical, and a power supply having a controller for outputting truncated-waveform drive pulses to the drive coil, and wherein the AC dual-coil comprises a feedback coil to induce a reverse flux to temper and stabilize a net flux, and a contact closing time of the movable electrical contact is controlled to shift to or adjacent to an AC load waveform zero-crossing point.

2. The contactor of claim 1 , wherein the controller controls a timing of an applied current based on a current waveform.

3. The contactor of claim 1 , wherein the controller controls a timing of an applied current based on an AC current waveform.

4. The contactor of claim 1 , wherein the controller controls a timing of an applied current based on a current waveform, whereby the truncated-waveform drive pulse has a half-cycle current waveform.

5. The contactor of claim 1 , wherein the controller controls a timing of an applied current based on a current waveform, whereby the truncated-waveform drive pulse is other than a half-cycle and full-cycle current waveform.

6. The contactor of claim 1 , wherein the controller controls a timing of an applied current based on a current waveform, whereby the truncated-waveform drive pulse has a quarter-cycle current waveform corresponding to peak load current.

7. The contactor of claim 1 , wherein the drive coil comprises a first coil and a second coil feedback connected to an original AC common center connection of the dual coil unit.

8. The contactor of claim 7 , wherein a reverse flux induced via the feedback connection in the feedback coil, thereby tempering and feedback stabilizing a net flux in the AC dual-coil actuator.

9. The contactor of claim 1 , wherein the truncated-waveform drive pulse coincides with the peak load current.

10. A method of limiting or preventing electrical contact bounce and arc duration, the method comprising the step of driving an AC dual-coil actuator to open and close electrical contacts of an electrical contactor, a drive pulse being applied to drive the AC dual-coil actuator having a truncated-waveform, a reverse flux is induced to temper and stabilize a net flux by a feedback coil of the AC dual-coil actuator, and a contact closing time of the movable electrical contact is controlled to shift to or adjacent to an AC load waveform zero-crossing point.

11. The method of claim 10 , wherein the truncated-waveform is based on a peak load current.

12. The method of claim 10 , wherein the truncated-waveform is a truncated AC waveform corresponding to peak load current.

13. The contactor of claim 10 , wherein the truncated-waveform drive pulse may be AC or DC.

14. The method of claim 10 , wherein the truncated-waveform drive pulse coincides with the peak load current.

15. A method of controlling electrical contact closing and opening delay, the method comprising the step of driving an AC dual-coil actuator to open and close electrical contacts of an electrical contactor, a drive pulse being applied to drive the AC dual-coil actuator having a truncated-waveform, a reverse flux is induced to temper and stabilize a net flux by a feedback coil of the AC dual-coil actuator, and a contact closing time of the movable electrical contact is controlled to shift to or adjacent to an AC load waveform zero-crossing point.

16. The method of claim 15 , wherein the truncated-waveform is based on a peak load current.

17. The method of claim 15 , wherein the truncated-waveform is a truncated AC waveform corresponding to peak load current.

18. The method of claim 15 , wherein the truncated-waveform is a truncated AC waveform truncated at the peak of the load current.

19. The contactor of claim 15 , wherein the truncated-waveform drive pulse may be AC or DC.

20. The method of claim 15 , wherein the truncated-waveform drive pulse coincides with the peak load current.

Assignees

• Johnson Electric Sa

Inventors

• Connell Richard Anthony

Classifications

• H01H47/22 Primary

  for supplying energising current for relay coil · CPC title

• H01H1/50 Primary

  Means for increasing contact pressure, preventing vibration of contacts, holding contacts together after engagement, or biasing contacts to the open position · CPC title

• H01H9/30

  Means for extinguishing or preventing arc between current-carrying parts · CPC title

• H01H3/28

  using electromagnet (for storing energy in a spring motor H01H3/30; for operating relays H01H45/00) · CPC title

• H01H7/16 Primary

  Devices for ensuring operation of the switch at a predetermined point in the AC cycle (circuit arrangements H01H9/56) · CPC title