| 摘要 |
A piezoelectric component (11) which operates as a mechanical/electrical transducer comprises a signal input (14) of a circuit (12) which possesses a control signal output and contains a digital bandpass filter (32) with a transmission range of, for example, 0.5 to 10 Hz and preferably 2 to 4 Hz. In this way, piezoelectric voltages outside the transmission range (32) are ineffective, which thus almost completely avoids disturbance due to temperature, impact, vibrations and sound waves. Apart from its function as a mechanical/electric transducer to perform control processes, the piezoelectric component (11) can also be used as an electromechanical transducer in order to produce sound waves, thus providing an audible signal in return. The circuit (12) possesses for this purpose a sound-frequency oscillator (42) and manually-operated means (30, 40, 41, 43) in order to connect provisionally this oscillator (42) to the piezoelectric component (11). |
