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:
Nov. 23, 1999
Filed:
Mar. 02, 1998
Tatsuya Hioki, Hadano, JP;
Keizo Sekido, Hadano, JP;
Stanley Electric Co., Ltd., Tokyo, JP;
Abstract
In a current cut-off type automated stroboscope circuit which controls a flashlight intensity by cutting off the current flowing through a flash lamp, a high-speed semiconductor switching device inserted in series with respect to the stroboscopic tube has been encountered up to now with malfunction and breakdown problems induced by chattering. To solve aforesaid problems, the present invention is to provide a xenon tube 1 with an IGBT 2 connected in series with respect to the xenon tube 1. The gate electrode of the IGBT is connected to two pnp-type transistors Q1 and Q2 substantially inbetween, both transistors of which are connected in series with respect to each other. The IGBT is controlled by turning on and turning off of the transistors Q1 and Q2. Furthermore, a time constant circuit which is formed of a capacitor C1 and a resistor R1 is connected to the transistor Q1. A gate voltage is applied to the IGBT 2 only for a certain period of time (one shot) which is defined by a time constant of CR product.