Regulating power unit for linear displacement transducer in order to compensate for coil temperature variations, by measuring AC and DC voltage differential across coil

摘要

An AC current superimposed on a DC current is used as the power signal for the transducer and this signal is supplied to a current branch point in the power unit (5) for both the coil (1) and the current measuring sensor (6). The AC voltage differential over the coil is measured and used to generate a signal corresponding to the position of the transducer element (2) relative to the coil. DC voltage differential over the coil is also measured to generate a signal corresponding to the coil temperature. The control method is used to measure linear movement and compensate for temperature variations in the transducer. Constant AC and DC generators are connected to a circuit containing the transducer coil and a current measuring sensor coupled in series with the coil. An Independent claim is also included for the control unit used to carry out this method.