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:
Nov. 02, 1982
Filed:
May. 13, 1981
Applicant:
Inventor:
Clarence D Lilienthal, Eden Prairie, MN (US);
Assignee:
Control Concepts Inc., Minnetonka, MN (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H02H / ;
U.S. Cl.
CPC ...
361 93 ; 323243 ;
Abstract
A safety circuit for a silicon controlled rectifier controller of the type wherein the current delivered to a load is determined by controlling the firing angle of the silicon controlled rectifiers. The safety circuit is capable of sensing a shorted condition in the silicon controlled rectifiers and automatically disconnecting the load from the AC mains in the event of such a short circuit condition. Load current is sampled at a time in the cycle where it is expected to be zero. If at the sampling time a non-zero condition is detected, a relay is made to operate to actuate a circuit breaker or to perform other desired functions.