PORTABLE TUNING DEVICE FOR MUSICAL INSTRUMENT

摘要

PURPOSE:To obtain a turning device for the musical instrument which is not affected easily by the external environment by using the electric oscillator circuit producing the continuous sound and the mechanical filter as the oscillation source and then using the electric tuning circuit to obtain the continuous reference sound. CONSTITUTION:The music heard through music receiver 2 is converted for impedance at turning circuit 5 after passing through amplifier 3 and multiplier 4, and then led into the mechanical filter of standard oscillator 6 via change-over switch 11 turned toward circuit 5. When the coincidence is obtained between the signals sent from circuit 5 and the natural oscillation frequency of the mechanical filter in oscillator 6, the output signal sent from oscillator 6 shows the peak value. And the output signal is supplied again to circuit 5 to receive the impedance conversion and furthermore converted into the driving signal via display driving circuit 7 to drive display unit 8. As a result, an accurate and quick turning becomes possible for the musical instrument even by the beginner. With change-over of switch 11, the tuning device functions as the oscillator circuit only.