Time-delay electronic device for apparatuses which can be switched on and off with a variable delay

摘要

The invention relates to a time-delay electronic device for apparatuses which are intended to be switched on and off with a variable delay, in which an RC element, which controls a control relay or the like for switching operations via electronic switching elements, determines the switching-on delay, and the switching-off delay is provided by the discharge of voltage-supporting buffer capacitors on the input side. In order that the delay times can be maintained in a defined manner irrespective of the load to be switched, and disturbances as a result of interferences with switching times of diagnostic and voltage monitoring apparatuses cannot occur, it is proposed according to the invention that, two trigger stages (14, 15) are used, one of which is connected to the control relay (5) as an output trigger stage (15) and can be controlled by the other trigger stage (input trigger stage 14) via the charge state of a capacitor (18) with separate charging (19) and discharging (20) circuits. Advantage: the invention allows a required drop-out delay to be maintained very precisely. The previously required bandwidth of the switch-off delay can be reduced. IMAGE