| 摘要 |
<p>The relay has at least two contacts and an excitation coil. An AC power source is connected to the contacts of the relay for applying a voltage of a prescribed frequency to them. A detector section compares a pulse current, induced in phase with the AC current supplied from the AC power source, with a reference value, as producing a detection signal. The positive and negative phases of a signal having a cycle longer than, and being asychronous with, the AC current, are delayed alternately or at random, thus generating a timing control signal. The control signal closes and opens the relay at random timings.</p> |
