Patent ID: 8023243

Claim:
A quick-acting valve, comprising: a valve opening, a valve member movable relative to the valve opening for controlling flow through the valve opening, a coil supplied by a voltage source for effecting movement of the valve member relative to the valve opening, a voltage-dependent resistor ( 33 ) provided between the voltage source and the coil, and an auxiliary voltage source connected in parallel to the coil, the voltage of said auxiliary voltage source being opposite to that of said voltage source, wherein the auxiliary voltage source is connected in series with a rectifier diode, the series combination of the auxiliary voltage source and the rectifier diode connected in parallel with the coil to rapidly discharge the current of the coil, and wherein the voltage-dependent resistor includes a plurality of electronic switches connected in series in the form of a cascade, said electronic switches each bridging a series resistor and being driven into the closing state when an input voltage applied by said voltage source falls below a given switching voltage whereby the electronic switches are driven simultaneously into the closing state.