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. 23, 1998
Filed:
Oct. 04, 1996
Michael Schlicker, Reichshof-Denklingen, DE;
Frank Schmitz, Bergisch-Gladbach, DE;
Schneider Electric SA, Boulogne Billancourt, FR;
Abstract
Safety circuits with an actuating device for electrical appliances, where the actuating device is capable of being operated by means of two key buttons or switch stacks are of use in many different areas of application. In order to create a generally suitable safety circuit, which is very simple and clear and which therefore brings with it low costs, which however stands up to all safety criteria, including the avoidance of any manipulation it is proposed that the two key buttons (S1, S2) each have a break contact (s1o, s2o) and a make contact (s1s, s2s) and act in combination with an associated driver stage (2), preferably a transistor driver stage with transistors (Q1, Q2, Q3, Q4), that the driver stage has two relays (K1, K2), that an astable circuit or multivibrator (1) with an elementary frequency of about 1000 Hz for the generation of two complementary square wave signals is connected to the relays (K1, K2) via contacts (k1, k2) so that the relays (K1, K2) are dynamically switchable.