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:
Apr. 23, 1996
Filed:
May. 05, 1995
Stefan G Mozar, Singapore, SG;
Tijmen C Van Bodegraven, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A voltage doubler (2) having a series arrangement of two smoothing capacitors (C1,C2), is able to use less expensive smoothing capacitors (C1,C2) having a far lower rated voltage which is only slightly above the maximum voltage occurring during normal operation. To this end, a first and a second over-voltage prevention circuit (30,31) are coupled across the smoothing capacitors (C1,C2) of the voltage doubler (2) to protect the smoothing capacitors (C1,C2) against over-voltage if one of the smoothing capacitors (C1,C2) is short-circuited. The first and the second over-voltage prevention circuit (30,31 ) may both be an over-voltage detector, or an under-voltage detector each being coupled across one of the smoothing capacitors (C1,C2). It is also possible to combine an over-voltage detector coupled across one of the smoothing capacitors (C1,C2) to an under-voltage detector coupled across the same smoothing capacitor (C1,C2). The over-voltage detector prevents an over-voltage across said one smoothing capacitor (C1,C2) if the other smoothing capacitor (C1,C2) is short-circuited. The under-voltage detector detects a short circuit of the one smoothing capacitor (C1,C2) and thereby prevents an over-voltage across the other.