Arc prevention circuit for a mechanical switch

  • US 5,821,642 A
  • Filed: 11/04/1996
  • Issued: 10/13/1998
  • Est. Priority Date: 11/04/1996
  • Status: Expired due to Term
First Claim
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1. An apparatus for selectively providing power to a load, the apparatus comprising:

  • a. means for measuring an amount of time between a first zero crossing of an AC supply voltage and a second zero crossing of the AC supply voltage; and

    b. means for initiating a change in condition of a switching relay coupled to the means for measuring wherein, the means for initiating initiates a change in condition of the switching relay an amount of time after a third zero crossing wherein the amount of time after the third zero crossing is equal to the amount of time between the first zero crossing and the second zero crossing less a delay time for changing a condition of the switching relay.

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