Charles B Leuthauser

US Patent:

40548457, Oct 18, 1977

Filed:

Dec 8, 1975

Appl. No.:

5/638844

Inventors:

Miroslav Glogolja - Hillsborough NJ
Charles Brook Leuthauser - Oldwick NJ

Assignee:

RCA Corporation - New York NY

International Classification:

H03F 2100

US Classification:

330207P

Abstract:

A normally-closed temperature sensitive switch which is heat coupled to the output transistors of an amplifier, is connected in series with a zener diode and the operating coil of a relay. When the voltage applied to the series circuit, which is the same voltage as applied to the amplifier, is insufficient to cause breakdown of the zener diode, the relay remains inactivated, and a pair of relay contacts across a feedback resistor of the output transistors remains closed. This keeps the output transistor off so that transients (which are the response of the amplifier to the rapid change in operating voltage when the amplifier is first turned on or when it is turned off) are substantially reduced. When the voltage reaches a given level at or close to the nominal operating voltage level, the relay is activated and the output transistors are turned on. When the temperature reaches a value such that the switch opens, the relay is inactivated and the output transistors are thereby turned off.