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. 26, 1990
Filed:
Oct. 07, 1988
Pieter J Bolhuis, Eindhoven, NL;
Adrianus M De Bijl, Eindhoven, NL;
Johannes M Van Meurs, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A DC/AC converter for igniting and supplying a gas discharge lamp (1) has two input terminals (C, D) intended to be connected to a DC voltage source. These input terminals are connected together by means of a series arrangement of a load circuit comprising at least the discharge lamp (1) and an induction coil (8), as well as a first semiconductor switching element (9). This load circuit being shunted by a circuit comprising a second semiconductor switching element (10). The switching elements (9, 10) are rendered alternately conductive and non conductive at a high frequency. The lamp is shunted by a third semiconductor switching element (12) which is conductive while the lamp electrodes (2, 3) are being pre-heated, whereafter the converter is rendered inoperative for a short period of time in order to ignite the lamp, which time is shorter than the time required to cool the lamp electrodes to below their emission temperature. The converter is thereafter rendered operative again.