Patent ID: 7446541

Claim:
A solenoid test device for testing lifespan of a solenoid, comprising: a clock circuit for generating a periodic voltage signal; a control circuit comprising: a first branch comprising a first input terminal coupled to the clock circuit for receiving the periodic voltage signal, and a first output terminal generating a first periodic control signal; a second branch comprising a second input terminal coupled to the clock circuit for receiving the periodic voltage signal, and a second output terminal generating a second periodic control signal; a first field-effect transistor comprising a first gate, a first drain, and a first source, the first gate coupled to the first output terminal for receiving the first periodic control signal, the first drain being grounded, the first source coupled to a first end terminal of the solenoid; and a second field-effect transistor comprising a second gate, a second drain, a second source, the second base coupled to the second output terminal for receiving the second periodic control signal, the second drain being grounded, the second source coupled to a second end terminal of the solenoid; and a power source coupled to a node between the first and the second end terminals of the solenoid, wherein the first and second periodic control signals control the first and second field-effect transistor to be conductive alternately, thereby grounding the power source through the first and second end terminals of the solenoid alternately.