Patent ID: 7403366

Claim:
A control circuit for an electromagnetic operating mechanism, the control circuit comprising: a timer; a first electronic switching device including a voltage follower and including a first output connected in series with an operating coil of the electromagnetic operating mechanism, the first electronic switching device being configured to activate for a duration of a pickup phase of the electromagnetic operating mechanism after a control voltage has been applied via the timer; a second electronic switching device including a switching path connected in series with the operating coil, the second electronic switching device being turned on while the control voltage is present; a rectifier circuit connected to a control input, the rectifier circuit including a second output and being configured to supply a smoothed operating voltage at the second output; a step-down DC voltage converter connected downstream of the rectifier circuit, the step-down DC voltage converter including a third output and being configured to supply a smoothed holding voltage at the third output; and a voltage source controllable by the timer and configured to activate the first electronic switching device by a pickup voltage; wherein: the timer is activatable by a ramping up of the operating voltage; the operating coil and the switching path of the second electronic switching device form a series circuit connected to the first output; the series circuit and the first electronic switching device are suppliable with the operating voltage; and the third output, the first output, and a control input of the second electronic switching device are interconnected, the third output being interconnected via a forward biased isolation diode.