12/220V Converter With Sine Output

12/220V Converter With Sine Output
How it work : The master oscillator, a voltage reference and comparator collected on DA2. External elements DD1 and DD2 repeated internal structure of the TL494, in the part that works is unstable at low frequencies (false positive D-flip-flop). Further, using the low-pass filter suppresses the upper harmonics of the PWM. LPF consists of two parts. First-DA1.1, with a smooth lowpass characteristic curves. Second-DA1.2 notch filter with a frequency of 150 Hz suppression. The analysis shows that the PWM

12 VDC TO 117 VAC / 60HZ POWER INVERTER

12 VDC TO 117 VAC / 60HZ POWER INVERTER
Capacitor C5 and potentiometer R12 figure out the frequency of the output signal at pin number 3 of IC1, the 555oscillator. The output signal is differentiated by C3 and C4 before it's input to the base of power¬†transistors Q1 and Q2 through diodes D1 and D2, respectively. The signal from IC1 is adjusted to 120 Hertz,¬†because the flip-flop created by transistors Q3 and Q4 splits the frequency by two. (more…)