Control device for a switching device with a holding coil and / or pull-in coil, and a method for controlling the current through the coil

摘要

It is advantageous when driving the switching device with a holding coil or pull-in coil and can be kept substantially constant regardless of the hold status or pull-state current through the coil. Also, it can be omitted complicated control unit storing the characteristic values ​​and the current measuring unit for costly measurement technology or circuit technology is desirable. In accordance with the present invention, there is provided a control unit connected to the switching element and a switching element connected to the coil, to form a pulse width modulated control signal by a control unit, an input, the pulse width of the pulse width modulation control signal to determine the current in response to a voltage signal, through the holding coil or pull-in coil to be kept constant. Such a controller may be incorporated in the switching device. The present invention also relates to a method for controlling the current through the holding coil or pull-in coil.