Low-cost and efficient home inverter circuit schematic

The picture shows the schematic diagram of a low-cost and efficient household inverter circuit . After the 12V power supply is turned on, the multivibrator composed of transistors VT1 and VT2, resistors R1 ~ R4, and capacitors C1 and C2 is powered on and starts to oscillate. VT1 and VT2 work in turn. The collectors of the two tubes output a square wave close to 50 Hz. The integral circuit composed of C3 and R5, C4 and R6 is integrally shaped into a quasi-sine wave, which is then inverted and amplified by VT3 and VT4 and then respectively stimulates VT5 and VT6 to make the power amplifier tubes VT7 and VT8 work.