| 摘要 |
PURPOSE:To make it possible to perform automatic measurement, by detecting the ON/OFF transition point of the output of an input level comparator of an AC signal to be measured for each polarity, holding the detected voltage, and measuring the input signal level in each polarity at the ON/OFF transition point. CONSTITUTION:For example, a switch 9 is turned OFF, and a reset state is released. Suppose that a clock input terminal 81 of a D.FF 8 is operated at a rising edge. Then, the FF is operated at the first OFF/ON transition point of an input level comparator 7 for an AC signal after the reset state has been released. Then, a hold signal is generated. Then, a sample/hold circuit 3 immediately becomes a hold state. The control voltage of the ON/OFF transition point of the comparator 7 is held at a control voltage input terminal 22 of a voltage control type amplifier 2. When the input signal level of the comparator 7 under this state is measured with an AC voltmeter 5, the AC signal input level at the OFF/ON transition point is obtained. The similar measurement is performed under the state a polarity switch 10 is switched to the side of an inverter 11. Then, the AC signal input level at the ON/OFF transition point is obtained.
|
