摘要 |
<p>An electrical-pneumatic system has a controller which has an input terminal for a reference variable signal, an input terminal for a regulating variable or feedback signal and an output terminal for a manipulated variable signal, which preferably is a pulse-width modulated signal. The controller will actuate a drive unit of an electrical-pneumatic pre-control unit, which has a 3/2 directional control valve that responds to the pulse-width modulated signal from the controller. The output of the 3/2 directional control valve is smoothed by being passed through a throttle and into a volume, and a pneumatic booster is connected downstream from the volume. The output of the pneumatic booster is sensed and provides the feedback signal.</p> |