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. 21, 1978
Filed:
Jul. 01, 1977
Richard E Stobbe, Greenfield, WI (US);
Michael R Cesarz, Mequon, WI (US);
Kearney & Trecker Corporation, West Allis, WI (US);
Abstract
Two transistors each have their emitter-collector circuits coupled in series between one end of a motor field winding and the opposite terminals of a D.C. voltage source to switch current flow in either direction through the winding. Two current sensors are provided, one coupled in series with each emitter-collector circuit. The voltage developed across each current sensor is applied through a driver circuit to the base of the other transistor so as to cut one transistor off when the other is conducting and vice versa, thereby eliminating the possibility of having both transistors conduct simultaneously which would short out the voltage source and burn out one or both transistors.