Abstract: A solenoid valve booster includes a control circuit connected between an input of a solenoid valve and AC power. The control circuit is consisted of a positive half wave turn-on voltage control circuit, a negative half wave turn-off delay control circuit, a logic NOR gate circuit, a phase control circuit, a rectifying and filtering circuit, and a start delay circuit. It can reinforce opening force of the solenoid valve, and lessening power consumed by the solenoid valve. Further, an isolate start circuit and an input control may be additionally connected with the booster described above for taking place of a conventional SSR (solid state relay).