VOLTAGE CONTROL OSCILLATING CIRCUIT

摘要

PURPOSE:To always keep the duty of an oscillation waveform at 1:1 by setting a charging circuit and a discharging circuit symmetrical with respect to the center potential. CONSTITUTION:The charging and discharging circuits of a capacitor C1 are formed symmetrically with respect to the center potential at resistances R1 and R2 as well as R3 and R4 respectively. An end of each of resistances R1 and R2 is connected to the 2nd voltage source which depends on a power supply VCC and control voltage VC. Then the junctures O and P between R1 and R2 as well as R3 and R4 are switched by a switch circuit consisting of transistor Q1 and Q2 and diodes D1 and D2. Charging and discharging are repeated alternately to the capacitor C1 to have oscillations. Thus the duty of an oscillation waveform can always be kept at 1:1.