Signal transducer for electrically controlled valves - has strip shaped piezo crystal controlling regulating unit with negative feedback loop

摘要

The servo valve is for hydraulic and/or pneumatic control systems, with improved dynamic characteristics. The control element in the transducer is based on a piezo crystal (10) that operates a regulating unit (16) on the valve. It acts as a current dependent control device (13). The piezo crystal is designed in strip form and deflects in its centre zone under the effect of two nozzles (14, 15). A hollow strip can be used. The deflection of the strip causes a pressure difference (DELTAp) at the regulating unit (18). This also includes a measuring device with a negative feedback loop to the amplifier (11).