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

Volume

44

Issue

2

fYear

1995

fDate

4/1/1995 12:00:00 AM

Firstpage

281

Lastpage

283

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;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/19.377831

Filename

377831