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:
Jan. 01, 1980
Filed:
Nov. 23, 1977
Hubertus M Chermin, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
The invention relates to a starter for igniting a low-pressure sodium lamp. The starter is provided with an oscillator circuit consisting of an electric coil, a first capacitor and a controlled semiconductor switching element. In accordance with the invention the starter also comprises a parallel circuit of a resistor having a positive temperature coefficient and a second capacitor, this parallel circuit and the oscillator circuit being in series. This series circuit is connected between two electrodes of the lamp. In the case where a defective lamp must be replaced by a new lamp--the supply voltage being switched on--in spite of the hot state of the resistor with positive temperature coefficient a plurality of starting pulses will nevertheless be passed through the second capacitor to the new lamp whereafter this lamp can ignite.