Amplifier circuit operable over a wide temperature range

Patent · Mon Jan 01 00:00:00 EST 1979

OSTI ID:863253

Kelly, Ronald D ^[1]; Cannon, William L ^[2]

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1. San Pedro, CA
2. Encino, CA

An amplifier circuit having stable performance characteristics over a wide temperature range from approximately 0.degree. C up to as high as approximately 500.degree. C, such as might be encountered in a geothermal borehole. The amplifier utilizes ceramic vacuum tubes connected in directly coupled differential amplifier pairs having a common power supply and a cathode follower output stage. In an alternate embodiment, for operation up to 500.degree. C, positive and negative power supplies are utilized to provide improved gain characteristics, and all electrical connections are made by welding. Resistor elements in this version of the invention are specially heat treated to improve their stability with temperature.

• DOE Contract Number: E(04-3)-1330
• Assignee: System Development Corporation (Santa Monica, CA)
• Patent Number(s): US 4134077
• OSTI ID: 863253
• Country of Publication: United States
• Language: English

Related Subjects

amplifier
circuit
operable
wide
temperature
range
stable
performance
characteristics
approximately
degree
500
encountered
geothermal
borehole
utilizes
ceramic
vacuum
tubes
connected
directly
coupled
differential
pairs
common
power
supply
cathode
follower
output
stage
alternate
embodiment
operation
positive
negative
supplies
utilized
provide
improved
electrical
connections
welding
resistor
elements
version
specially
heat
treated
improve
stability
performance characteristics
resistor element
provide improved
differential amplifier
temperature range
power supply
heat treated
alternate embodiment
electrical connection
amplifier circuit
wide temperature
power supplies
output stage
directly coupled
tubes connected
vacuum tube
vacuum tubes
electrical connections
ceramic vacuum
performance characteristic
geothermal borehole
tubes connect
provide improve
/330/