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. 15, 1991
Filed:
May. 05, 1989
Anton Vorel, Eggenfelden, DE;
Abstract
A driver circuit for switching on lamps with low cold resistance. The circuit includes a power transistor (T5) of which the collector-emitter path is connected to the lamp (12) in a series circuit which lies between a positive terminal and a ground terminal of a supply voltage source. The circuit further includes an RC member comprising a resistor (R1) which is connected on one side to the ground terminal and a capacitor (C) which is connected in series with the resistor and on one side to the positive terminal of the supply voltage source. A comparator (38) compares the voltage at the resistor (R1) with the voltage at the collector of the power transistor (T5) and furnishes at an output a blocking signal for the power transistor (T5) when the voltage at the resistor (R1) is more negative than the voltage at the collector. A limiting member (T4) limits the voltage at the resistor (R1) to a voltage value lying above the saturation voltage of the power transistor (T5).
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile