| 摘要 |
PURPOSE:To adjust the optimum offset value of the sensor output of the electronic musical instrument automatically by providing a control means which varies the value of an offset control signal stepwise. CONSTITUTION:The output value of an A/D converting means 11 corresponding to the offset quantity of the sensor output is controlled automatically into a range predetermined by the control means. For example, the inverted input terminal of an operational amplifier 9a is grounded through resistances Rb and Rc in order and connected to the output terminal through a resistance Rd, and the output signal of an inverting amplifier 9b is supplied to the connection point between the resistances Rb and Rc. An offset control signal S0 is supplied to the input terminal of the inverting amplifier 9b from an D/A converter 10. Consequently, the output offset of the operational amplifier 9a is adjusted with the value of the offset control signal S0 to adjust the offset value of the sensor output Sa. |
