Title :
Adaptive current sources and feedback applied to the cryogenic current comparator
Author :
Wood, Barry M. ; Schumacher, Bernd
Author_Institution :
Inst. for Nat. Meas. Stand., Nat. Res. Council of Canada, Ottawa, Ont., Canada
fDate :
4/1/1995 12:00:00 AM
Abstract :
We present a novel current source for the cryogenic current comparator resistance bridge which is adaptable to many coil, resistance and filtering configurations. To achieve optimum performance of the system both current feedback from the SQUID and feedback from the voltage detector are examined and incorporated into the design. The properties of the new design are improved flux tracking, leakage, and flexibility without comprising the self checking capability and accuracy. The system has been used at the NRC over the resistance range of 1 Ω to 1 MΩ
Keywords :
SQUIDs; bridge circuits; bridge instruments; circuit feedback; constant current sources; cryogenic electronics; current comparators; electric resistance measurement; measurement standards; 1 ohm to 1 Mohm; DVM; SQUID; adaptive current sources; cryogenic current comparator; feedback; flexibility; flux tracking; leakage; optimum performance; resistance bridge; voltage detector; Bridge circuits; Bridges; Coils; Cryogenics; Feedback; Filtering; Measurement standards; Resistors; SQUIDs; Superconducting device noise;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
