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:
Dec. 18, 1990
Filed:
Jul. 01, 1988
John J Kuhn, Gibsonia, PA (US);
PPG Industries, Inc., Pittsburgh, PA (US);
Abstract
A ramp circuit for a control loop which receives a signal from a controller and sends a signal to a controllable means to limit the slew rate of the controller signal. A capacitor functions as a storage means and a reset means is provided to rapidly discharge the capacitor in the event of a decrease in power to the control loop. The capacitor is charged through a diode which limits discharge in normal operation. The discharge and reset is performed by a normally reverse biased diode and series resistance connected to the controller positive supply voltage. A current limiting means is provided to charge the capacitor a lower linear rate by turning on a transistor and shunting excess current around the capacitor. An external reset is provided by an additional diode and series resistance for connection to a remote positive supply voltage or relay contact. The output is buffered by an emitter follower to limit loading by the controllable means and protection circuitry to provide immunity to induced electrical currents at the output.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile