This low-power 25 watt power inverter circuit which makes use of only 9 electronic parts. The inverter turns 10V to 16V DC input into 60Hz, 115V square-wave power output to operate AC electronic devices approximately 25W. The very first section of the 556 timer chip is wired as an astable oscillator with R2 and C1 setting the frequency. The output is presented at pin 9. Resistor R3 and R4 maintain output transistors Q1 and Q2 from loading down the oscillator.
The two transistors drive the transformer push-pull fashion. When one transistor is biased-on, the other is cut-off. The transformer is a 120V / 18V CT unit which is connected backward, so that is steps the voltage up rather than down. Oscillator circuit U1, R1, R2 and C1 operates from about 4 to 16V with a really stable output.
25 watt power inverter circuit diagram source: dcinverter.blogspot.com