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:
Mar. 25, 1986
Filed:
Oct. 24, 1984
Siemens Aktiengesellschaft, Berlin & Munich, DE;
Abstract
In a circuit arrangement for drive of a thyristor with a phototransistor, the collector-emitter path of the phototransistor is between one of two alternating voltage terminals and a gate terminal of the thyristor. In order to prevent an activation of the unilluminated phototransistor due to a steep voltage edge (dv/dt) load), its base current given such a load is carried off via an IGFET of the enhancement type. This IGFET is controlled by an IGFET of the depletion type acting as a current source which lies between a gate terminal and source terminal of the enhancement type IGFET. A capacitor is connected in series with the depletion-type IGFET. This series connection lies between the two alternating voltage terminals.