PURPOSE: To set the initial level of each contacts potential of 1st-3rd capacitors and to decide a transfer charge quantity accurately by providing a circuit comprising 1st-3rd resistors, 1st and 2nd operational amplifiers, a switch and a battery to the charge transfer circuit.

CONSTITUTION: The circuit consists of 1st-4th resistors 100-103, 1st and 2nd operational amplifiers 104, 105, a switch 106 and a battery 107 and connects to 1st-3rd capacitors 300-302 and 1st and 2nd switches 303, 304. Thus, the circuit consisting of the 1st-3rd resistors 100-102, the 1st and 2nd operational amplifiers 104, 105, the switch 106 and the battery 107 is used to set the initial value of each contacts potential of the 1st-3rd capacitors 300-302 and the transfer charge is accurately decided.