Patent ID: 6618234
Filing Date: 2003-09-09
Classification: A01G,H02H

Abstract:
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.