| 摘要 |
PURPOSE:To adjust automatically an electronic potentiometer to a level at the power supply interruption when the power supply is applied again, by storing the adjusting position of the electronic potentiometer with the power supply interrupted. CONSTITUTION:The electronic potentiometer 2 is controlled with a signal analog-converting a control signal from a microprocessor (MP)6 at a D/A converter 7, and a signal from an input terminal 1 is adjusted for the level and impressed to a recording amplifier 3. A control signal given from the MP6 to the D/A converter 7 is controlled with switches 9, 10 conventionally. A switch 11 is interlocked with a power switch and turned on when the power switch is turned off, to store the control signal of the MP6 in this case to a storage device 8 having a backup power supply. When the power switch is turned on, the control signal in the storage device 8 is given to the D/A converter 7 via the MP6 and the electronic potentiometer is set to the level where the power supply is interrupted. |
