| 摘要 |
<p>The control circuit comprises a source of relatively high voltage which can quickly cause current to flow in the coil. A semiconductor device responds to external control and connects the high voltage source to the coil. It is operated with almost no energy consumption. A first device detects current in the coil and blocks the semiconductor switch when the current has reached the specified value, and then makes it intermittently conducting in order to maintain the specified current intensity. A second, externally controlled device connects the voltage source to the coil with opposite polarity in order to accelerate the current drop.</p> |
