| 摘要 |
A device which permits viewing of the opening of one or more electrical contacts of appliances connected in series and control of an automatic device without overloading the circuitry. It comprises a housing containing a power pack, a constant-current generator between two given poles, comparators which control the voltages at two given points by operating two indicators and a relay, the contacts of which are available at given points, and a time-delay switch. Located on the front face are: a line-control indicator, indicators for localizing defects, the indicator of the state of the said relay and the control knob of the time-delay switch situated in the centre of the face. The device according to the invention is particularly suited to the detection of power failures. |
