| 摘要 |
<p>A device for automatically protecting telecommunication apparatus against input signals of improper polarity. The device does not use any energy or voltage after polarity match is established, so that use of the device does not degrade the incoming signal. A set of relay contacts, controlled by diodes, assures that the signal applied to the load is of proper polarity. There is no voltage drop between the exchange line incoming cable and the load.</p> |
