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Lightning protection for irrigation controls

  • US 6,618,234 B1
  • Filed: 09/08/2000
  • Issued: 09/09/2003
  • Est. Priority Date: 09/08/2000
  • Status: Expired due to Term
First Claim
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1. A lightning-resistant irrigation control system, comprising:

  • a) a non-earth-grounded field wiring circuit exposed to induced lightning surges;

    b) an AC valve operating circuit arranged to selectively apply operating power to said field wiring circuit, said valve operating circuit including control components including first portions forming a part of said valve operating circuit, and second portions operating said first portions but being electrically isolated therefrom;

    c) voltage-sensitive plasma discharge devices connecting said valve operating circuit to earth ground;

    d) DC logic circuitry arranged to operate said second portions of said control components;

    e) said logic circuitry being electrically isolated from said valve operating circuit; and

    f) all parts of said valve operating circuit being capable of withstanding a maximum expected lightning surge current for the period of time between the onset of said surge current and the firing of said plasma discharge devices.

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