An engergizing circuit for a solenoid valve has a power source connected to a solenoid coil of the solenoid valve through on-off contacts. The energizing circuit includes a capacitor and a solid-state surge absorber which are respectively connected in parallel with the solenoid coil, and the surge absorber...http://www.google.ca/patents/US4246621?utm_source=gb-gplus-sharePatent US4246621 - Energizing circuit for solenoid valve
