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:
Jan. 03, 1995
Filed:
May. 03, 1993
Applicant:
Inventors:
Glade B Bacon, Everett, WA (US);
Heber P Farnsworth, Snohomish, WA (US);
Assignee:
John Fluke Mfg. Co., Inc., Everett, WA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361106 ; 361 56 ; 361108 ; 361111 ;
Abstract
A protective circuit for the input of a multimeter is provided with series connected thermistors partially shunted by a varistor whereby overload voltage is distributed between the thermistors enabling protection at higher voltage levels. Shunt connected varistors protect primarily against transient overloads and are thermally coupled to the aforementioned thermistors to bring the thermistors more rapidly to their high resistance condition such that damage to the varistors is avoided and continued protection is provided.