The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 02, 1981
Filed:
Sep. 18, 1978
Applicant:
Inventors:
Stephen H Outram, Frimley, GB;
Geoffrey A Luckhurst, Yateley, GB;
Assignee:
The Solartron Electronic Group Limited, Farnborough-Hampshire, GB;
Primary Examiner:
Int. Cl.
CPC ...
G01R / ; H01H / ; H03K / ;
U.S. Cl.
CPC ...
324115 ; 324 / ; 3403 / ; 361208 ;
Abstract
The variable attenuator and variable current shunt of a battery-powered auto-ranging digital multimeter uses latching relays, each of which, since it is stable in each of its two switching states, requires only a current pulse to change its state. The circuit which operates the relays provides a drive pulse only when the desired relay state differs from the actual state, thus minimizing the power required, and includes a tank circuit for minimizing disturbance to the multimeter power supply. To ensure that the tank circuit can recharge, each relay is driven by a tri-state output.