Currently, electrical energy from renewable energy sources such as wind energy, fuel cells, and solar cells has begun to be developed in Indonesia. However, the energy produced from this type of power plant is mostly still in direct voltage (DC). At the same time, the electrical load that must be served is electrical, primary energy consumption in the form of AC voltage. For that, we need an inverter that can convert DC voltage into AC voltage. The inverter is an electronic device capable of converting a DC voltage source into an AC voltage source with the desired magnitude and frequency. In general, current inverters are not equipped with AC output voltage control, so when the inverter load is large, it causes a voltage drop, so to overcome this, it is necessary to design an inverter that can control the output voltage through feedback so that the output voltage remains stable. In this research, the inverter is designed using IC SG3525 as an oscillator generator, IRFZ44 Mosfet driver as a power amplifier, and a step-up transformer to increase the 12V voltage to 220V. The test is done by observing the output waveform frequency and output voltage using an oscilloscope, observing the output voltage, current with a multimeter, and observing the feedback voltage to see the stability of the output voltage. The test results show that the designed inverter can produce square wave output with a maximum power of 100 Watts, an output voltage of 220V, and a frequency of 50Hz.