| 摘要 |
PURPOSE:To substantially prevent the influence of external noises and to improve detection accuracy by inputting a sine wave signal to an integrator, inputting the sine wave signal to this integrator and obtaining the definite integral of the sine wave signal in the sample region of the reference signal inputted to the integrator. CONSTITUTION:The impulsive reference signal 23 is inputted to a second switch 6 and a reset pulse generating circuit 30 while the sine wave signal 2 of, for example, Asinomegat is held inputted to a first operational amplifier 1. The switch 6, then, turns on and the signal is integrated by the time constant of the integrating resistor R and integrating capacitor C1 in the sample region A. The definite integral of the sine wave signal corresponding to 180 deg. component of the sine wave signal 2 is expressed by equation in such a case. The hold voltage 10a detected in the sample region A in the hold region B is outputted from an output terminal. The output of the hold voltage 10a is stopped as the reset pulse 30 generated from a reset pulse generating circuit 30 turns on the first switch 22 in the reset region C. |
