Accession Number : ADD009702

Title :   Isolated Load Switching with Surge Suppression.

Descriptive Note : Patent Application,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Bezdek,Thomas G

Report Date : 30 Jun 1982

Pagination or Media Count : 19

Abstract : Relay contacts provide the principal switching between a D.C. power source and the load. An SCR in series with a limiting resistor by phases the relay contacts during initial turnon to absorb the inrushing surge to capacitors of the load. Optical couplers provide isolation from a remote control. A transistor blocking oscillator is coupled between one optical coupler and the trigger of the SCR for turn-on. Delay timing includes a collector-base capacitor at a transistor of the other optical coupler. A Zener diode couples the timing circuit to a transistor amplifier, which operates the relay. The turn-on circuit is then disabled. A turn-off pulse to the second optical coupler turns off the transistor amplifier, which opens the relay. (Author)

Descriptors :   *Patent applications, *Switching circuits, *Silicon controlled rectifiers, *Electric relays, *Power supplies, Transistor amplifiers, Optical equipment, Resistors, Couplers, Oscillators, Suppression, Couplers, Capacitors, Remote control, Circuits, Timing circuits, Limitations, Phase, Blocking, Transistors, Surges, Relays, Isolation

Subject Categories : Electrical and Electronic Equipment
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE