Control device for the actuation of switchgears

US5497380A · kind A · utility

Assignee

• Landis & Gyr Technology Innovation AG · CH

Inventors

• Klaus Bott · Ludwigshafen, DE
• Bernd Schukraft · Karlsruhe, DE

Key dates

• Filing date: Dec 14, 1994
• Grant date: Mar 5, 1996
• Expiry date: Dec 14, 2014

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01H9/167
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

Information appearing in the form of analog low-voltage signals (V.sub.1 ;V.sub.2) on call lines (ML1;ML2) which represents the states of switchgears (2.1;2.2) is conveyed in parallel to a circuit block (4). The information is digitalized at certain points in time and in accordance with a predetermined voltage level as binary values "0" or "1" and is transmitted in series to a control logic unit (1). The circuit block (4) is preferably a plurality of shift registers in cascade connection. Each call line is coupled via a coupling element (3.1;3.2) to the circuit block (4) so that the circuit block (4) is not destroyed even when overvoltages occur. In the closed state of a switchgear (2.1;2.2), a signal voltage (U.sub.1 ;U.sub.2) with changeable course appears at the corresponding input (4.1;4.2) of the circuit block (4). In the open state of a switchgear (2.1;2.2), the signal voltage (U.sub.1 ; U.sub.2) is a uniform signal (U.sub.1 ;U.sub.2). The digitalization is effected by means of a synchronization device (8) at points in time when the level of the changeable signal voltage (U.sub.1 ;U.sub.2) is clearly different from the level of the zero-point voltage (G). These controls are e…