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:
Aug. 30, 1988
Filed:
Sep. 22, 1986
Andries C Pasma, Drachten, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A power supply circuit which maintains the voltage across a first capacitor (C.sub.1) substantially constant over a wide range of mains voltages, the capacitor (C.sub.1) energizes a motor (M) and is charged during the rising edges of the applied mains voltage in that above a specific input voltage (U.sub.min) a first transistor (T.sub.1) is turned on via a second capacitor (C.sub.2) and a first resistor (R.sub.2). When the rectified mains voltage at the output of a diode (D.sub.1) exceeds a specific value (U.sub.2) defined by a first zener diode (Z.sub.2), a second transistor (T.sub.2) is turned on. Consequently, the first transistor is turned off. When the first transistor (T.sub.1) is cut off, the first capacitor is discharged through the motor. The second capacitor is then discharged via a second zener diode (Z.sub.1) and prevents the first transistor from being turned on.