| 摘要 |
PURPOSE:To form a polarity inversion circuit not requiring a filter suppressing charging noise by providing a current switching means supplying a timewise slow control current to a control electrode of 1st - 4th transistors (TRs). CONSTITUTION:The titled circuit consists of a 1st differential amplifier circuit comprising two TRs 8, 9 whose emitters are connected to the other terminal of a 1st constant current source 5 whose one terminal is connected to a common potential and consists of two TRs 10, 11 whose emitters are connected to other terminal of a 2nd constant current source 6 whose one end is connected to a power supply and controlled to supply the same current as that of the 1st constant current source 5. Then a current controlling each of the 1st differential amplifier circuit and the 2nd amplifier connected in a push-pull form is supplied while the value is varied at a prescribed rate with respect to time thereby smoothing the rate of change of current in changing the direction of the line current. Thus, the charging noise at polarity inversion is minimized and a filter circuit comprising a large capacitance capacitor and a coil is not required.
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