摘要 |
<p>The control device has a switch (5), controlled by a clock source (4), connected in series with a solenoid (1) for operation of a magnetic armature (3) and closed for application of a DC voltage to the solenoid, which is temporarily interrupted upon detection of a given current through the solenoid, via a series current detector switch (7). An ohmic resistance (6) across the current detector switch determines the holding current for the armature in conjunction with the response threshold of the latter, a second ohmic resistance (9) connected in the current circuit under control of a second clock source (8), for providing a displacement current for the armature.</p> |