| 摘要 |
<p>Electronic device for the energization of an electromagnetic element, particularly a troke-coil or a coil of an electromagnetic switching apparatus having a magnetic circuit with a coil, a yoke and an armature. A comparator (5) receives a predetermined current order value U(Isoll) and an actual measured cerment value U(Iist). When the actual value goes down below the order value, the comparator (5) actuates, through a monostable flip flop element (6), a switching transistor (1) supplied by a supply voltage Uv, arranged in the main current circuit of the electromagnetic element (2). After the constant conduction duration tein has elapsed, it blocks the transistor (1). With a variable conduction duration tein of the switching transistor (1), there results a variation of the current order value, function of the set conduction duration. In order to obtain a reliable operating mode of an electromagnetic switching apparatus comprising a coil, there is established a high actuation current order value and, after operation of the switching apparatus, a reduced maintaining current order value. For the operation of different switching states of the switching apparatus, the coil inductivity is taken into account.</p> |
