| 摘要 |
PURPOSE:To enhance the reliability of the device by making compensation with the reverse output of the 2nd amplifier in the case when offset voltage falls due to the drift of the 1st amplifier and thereby undesired discharge is made. CONSTITUTION:In the case when input turns zero in the nighttime or due to any other reasons and the output v1 of the amplifier Ic1 falls below the voltage of a potential memorizing element MD due to the drift, the potential memorizing element MD makes discharge through the intermediary of a resistance R2. When the voltage of the element MD turns negative through this discharge, the voltage of the output v2 of the amplifier Ic2 becomes positive and it charges the potential memorizing element MD through the intermediary of a resistance R7 from the point of time when the voltage thereof exceeds the forward voltage of a diode D. Thus, the voltage does not fall below the voltage of the element MD at the point of time when discharge current through the resistance R2 and charge current through the resistance R7 are balanced, whereby the excessive discharge of the potential memorizing element beyond -100mV is prevented. |
