| 摘要 |
PROBLEM TO BE SOLVED: To use inexpensive parts by conducting preliminary operation and input operation to fall in an input range of a D/A converter even under the condition where the output of an amplifier scales over due to an error of used parts. SOLUTION: This circuit includes an adder 2, an amplifying circuit 3, an A/D converter 4, a control part 5 and a D/A converter 6. The output of the control part 5 is input to the D/A converter 6. The outputs of the D/A converter 6 and a signal circuit 1 are input to the adder 2, and the output of the adder 2 is amplified by the amplifying circuit 3 and then input from the A/D converter 4 to the control part 5. Accordingly, the output level of the signal circuit 1 can be shifted by the control of the control part 5. The input cycle includes preliminary operation 7, correcting operation 8 and input operation 9, and the preliminary operation 7 adjusts the output of the D/A converter 6 even under the condition where the amplifying circuit 3 scales over to be inoperative, so that the output range of the amplifying circuit 3 falls in the input range of the A/D converter 4. |
