摘要 |
The switching valve of a quick-operating slider system is an electrically operated stop valve. In the case of a required rapid shutoff, the coil (19) must be de-energized in a very short period of time in order to allow the switching valve (18) to open. For this purpose, a voltage-dependent resistor (33) is provided between the voltage source (25) and the coil (19), said resistor (33) having a high resistance below a switching voltage (Us), but a negligibly small resistance above the switching voltage. An auxiliary voltage source (35) is connected in parallel to the coil (19), the voltage of said auxiliary voltage source (35) being opposite to that of the voltage source (25). In this manner, the switching valve is rapidly opened both when a corresponding signal is received and in the case of power failure.
|