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:
Jul. 22, 1980
Filed:
Dec. 08, 1978
David T Cavil, Menomonee Falls, WI (US);
Gerald N McAuliffe, Lincoln, NE (US);
Outboard Marine Corporation, Waukegan, IL (US);
Abstract
Disclosed herein is a direct current motor control circuit adapted for connection to first and second supply terminals of DC power source and to a DC motor connected between the positive and negative terminals of a DC power source, the control circuit including a solenoid including a solenoid coil having one end connected to the first supply terminal and having an opposite end, and having a pair of solenoid contacts connected in series relation with the DC motor between the positive and negative terminals and which close to energize the DC motor when current flows through the solenoid coil. The circuit also includes semiconductor switching means having a first terminal connected to the opposite end of the solenoid coil, a second terminal connected to the second supply terminal, and a third terminal, the switching means being selectively rendered conductive for allowing current flow through the solenoid coil, and protective solenoid latching circuit means including an optical coupler for electrically isolating the solenoid contacts from the solenoid coil, the coupler having a light sensitive transistor connected to the third terminal of the semiconductor switching means and having an LED, the protective circuit means also including an upper voltage threshold means connected in series relation with the LED across the solenoid contacts so that when the voltage across the solenoid contacts exceeds a predetermined upper value, current flows through the voltage threshold means and the LED to render conductive the light sensitive transistor which shunts the third terminal of the semiconductor switching means to prevent conduction of the semiconductor switching means and chatter of the solenoid contacts.