| 摘要 |
Electrical protection systems which contain a resistor and a relay in series with a load, and a PTC device which is connected in parallel with the load and in series with a coil which controls the relay. The PTC device is thermally linked to the resistor and in consequence the relay opens if an overcurrent heats the resistor. The relay coil can be activated remotely by means of an RC circuit, and a diode or other electrical component permits current to pass through the RC network to the relay coil but prevents it from flowing in the opposite direction. |
