Patents Assigned to Electronic Specialty Corporation
  • Patent number: 4959746
    Abstract: A contact protective circuit for a relay detects a transient in the relay operating coil and turns on a low resistance power MOSFET in shunt relation with the contacts before the contacts close or open whereby arcing or deposition of metal on the contracts is avoided. Timing circuitry is provided for controlling the MOSFET to conduct large direct currents for short periods of time. In one embodiment, a ramp up circuit responds to a voltage level in a control signal to drive the operating coil and power a DC-to -DC converter and a timing circuit. The invention provides for hot side switching as well as cold side switching of a load.
    Type: Grant
    Filed: August 29, 1988
    Date of Patent: September 25, 1990
    Assignee: Electronic Specialty Corporation
    Inventor: Chester C. Hongel