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:
Jun. 22, 1999
Filed:
May. 06, 1996
G Stephen Perreira, Carpinteria, CA (US);
Kilovac Corporation, Carpenteria, CA (US);
Abstract
The DC actuator control circuit with voltage compensation, current control and fast dropout period employs an electronic chopper incorporating an oscillator having a variable duty cycle controlled by sensing of coil current. Coil current is sampled through a series resistor by a feedback amplifier which increases or decreases the period in which the switch for the coil circuit remains on to sustain average coil current at the desired MMF. A threshold detector provides an initial triggering signal to initiate operation of the actuator and the control circuit responsive to a predetermined source voltage and a gate signal generator responds to the triggering signal with a time constant sufficient to drive the coil through a pickup interval. Inrush current is limited by the oscillator through sensing of coil current. A dropout switch for opening the sustaining current return circuit which opens upon removal of source voltage provides a high impedance for rapid current drain from the coil thereby eliminating regeneration effects.