Converter 12 Vdc to 230 Vac or Inverter

Converter 12 Vdc to 230 Vac or Inverter
As shown in the Inverter circuit diagram obove , Its used as the oscillator stage astable multivibrator contained in IC1, a CMOS 4047 (this cult series 40xx series) by varying the resistance value of R1 trimmer (220 k total resistance) can vary the oscillation frequency of 40 Hz to 70 Hz square wave, phase shifted by 180 °,  Output pin 10-11 will drives two NPN transistors TR1-TR3, which in turn is fed to the TR2-TR4. (more…)