| 摘要 |
<p>In a static trip device with its own current, the measurement voltage Vm which is representative of the current crossing the conductor (12) to be protected and is applied to the input of an electronic processing unit (26), is also applied to the cathode of a thyristor (34) connected in series with the tripping coil (14) and receiving on its gate the commands for tripping the processing unit (26). A Zener diode (40) is connected between the gate of the thyristor and earth so as to fix an instantaneous trip level for the trip device. In this way, a short-circuit in the conductor causes instantaneous tripping of the circuit-breaker (10) independently of the value of the mains voltage (V). …<IMAGE>… </p> |
