Ted Bildplatten Aeg Telefunken

Gerhard Dickopp

Horst Redlich

Werther Hartmann

A method and apparatus for reducing a resonance peak in a piezoelectric transducer for mechanically recording a signal having a band width of several MHz, in particular on a video disk comprising, applying a countercoupling current across terminals of the transducer for counteracting a current flow in the parallel capacitance of the transducer. A circuit of the invention comprises a piezoelectric transducer having two terminals and including in series a characteristic inductance, capacitance, and resistance, and a parallel capacitance characteristic in parallel to the series characteristic, a signal generator for generating the signal to be recorded, a transformer having a primary winding connected to the signal generator and a secondary winding connected to one terminal of the transducer with a symmetrically disposed central ground connected to the secondary winding. An opposite end of the secondary winding and the other terminal of the transducer are connected to a loading resistor and in turn connected to ground. A compensating capacitor is connected between the other end of the secondary winding and the loading resistor for compensating current flowing through the characteristic parallel capacitance of the transducer. A countercoupling line is connected between the loading resistor and one input of the signal generator so that the countercoupling current may be applied to the signal so as to reduce the resonance peak in the piezoelectric transducer.

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Hanover, Germany

Gerhard Dickopp