2 12V-120V Modified Sine-Wave Inverter

It is based on 12V-220V inverter but modified to have a 120V AC output. This inverter has two versions, the 60Hz and 50Hz.
inverter schematic

Part List (60Hz, 120V):
R1, R - 20 kilo-ohms 1/4W
R3 - 1.2 kilo-ohms 1/4W
R4, R6 - 560 ohms 1/4W
R5, R7 - 5.6 kilo-ohms 1/4W
C1 - 200nF capacitor (parallel two 100nF)
C2 - 10uF electrolytic capacitor rated 16V
C3 - 470uF electrolytic capacitor rated 16V
C4 - 100nF capacitor
Q1, Q2 - IRFZ44N or similar N-channel power Mosfet
X'former - 10V-0V-10V to 20V transformer (minimum 500VA if required)
LM7809 - IC regulator
LM555 - timer IC
CD4017b - 5-stage Johnson counter

Part List (50Hz, 120V):
R1, R2 - 12 kilo-ohms 1/4W
other parts are the same

Parts pins and diagrams:
555 IC pins
CD4017 pins
7806, 7808, 7809 pins
The output frequency is controlled by the 555 timer IC. The output frequency is equal to 4 times the output frequency of 555. You can replace the values of  R1, R2, and C1 to change the frequency (use 555 calculator in astable mode). You can replace R2 with 20 kilo ohms potentiometer so that you can adjust it to ensure that the output frequency is 50Hz or 60Hz (of course with the help of oscilloscope or any frequency monitoring device).

Note: Output voltage of the inverter is high and can electrocute when touched, exercise safety always.