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:
May. 05, 1992
Filed:
May. 07, 1990
Jeffrey P Kotowski, Rolling Meadows, IL (US);
Brian Chapman, Gurnee, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
Overvoltage protection circuit (10) has a power transistor (11) that drives an inductive load (19). A resistor (16) is connected between an output electrode (14) of the transistor and a control electrode (12) of the transistor, and a constant current source (18) is also connected to the control electrode. The resistor and constant current source determine an effective zener voltage to limit the maximum voltage which can exist at the transistor output electrode (14), and this is accomplished without the use of a zener diode while utilizing a minimum number of components. This effective zener diode voltage can be readily adjusted by adjusting either the magnitude of the resistor (16) or the constant current source (18).