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US 6,618,234 B1Granted
Lightning protection for irrigation controls
AssigneeThe Toro Company
InventorsAli Abdelghani, Uzair Siddiqui, Derek A. Harris, Lam Mau Nguyen, Arnold Ray Nelson, Michael Larry Bell
Life of this patent
Estimating the term…
Abstract
Damage to electronic golf course sprinkler valve controls from lightning current surges is prevented by electrically isolating the actual valve control circuit from the logic circuitry that controls it, using in the valve control circuit only components and printed traces that can withstand at least as much power dissipation as the field wiring, and grounding each valve control individually to earth ground through a plasma discharge device.
Claims5
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.
4 more elements
Dependencies are inferred from the claim text.