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. 03, 2008
Filed:
May. 25, 2005
John P. Thurk, Madison, WI (US);
Eric G. Rasmussen, Waunakee, WI (US);
Eric W. Suomi, Madison, WI (US);
John P. Thurk, Madison, WI (US);
Eric G. Rasmussen, Waunakee, WI (US);
Eric W. Suomi, Madison, WI (US);
Electronic Theatre Controls, Inc., Middleton, WI (US);
Abstract
A current sensing transformer having a low impedance primary winding is connected in series with a filter and load circuit supplied with output current by a high frequency switching PWM power supply such as a sinewave dimmer. Sensed output current is supplied to a microprocessor based programmable controller. The controller performs a routine including a family of overcurrent tests. Tests of the family are satisfied by the presence of different output current values for different time durations. At least one of the tests is enabled only at low requested output voltages or dimming levels. In response to satisfaction of any of the tests, a series power switching stage of the power supply is rendered nonconductive to shut down the power supply.