In operating synchronous motors as synchronous generators, synchronous motors do not have field excitation or self excitation, so a DC voltage power supply that can be adjusted for the rotor field excitation needs is needed. The amplifier or excitation itself is used to produce field excitation on the synchronous motor so that it can operate as a synchronous generator. The DC power supply circuit can be a separate circuit from the generator or an inseparable circuit in this case the generator output voltage is rectified and used as a field excitation power supply. The method used to complete this research is research and development which is a method used to develop certain models, tools or applications based on the research process. Where synchronous motors are operated as synchronous generators using separate field amplifiers, with a load of 0 -210 Watt, it turns out that What happens is that the greater the load given to the generator, the generator speed and the output voltage generated from the generator decreases, so the generator speed must be stabilized again at 1500 rpm and the output voltage at each phase must be stabilized at 220 VAC, while using own field amplifier with a load of 0-240 Watt, what happens is the generator excitation voltage generated from the field amplifier itself (self excitation) will remain stable, and will be synchronous motor rotation decreases and must be stabilized again at 1500 Rpm rotation, the generator excitation voltage which is supplied from the field amplifier itself remains stable. While the output voltage on the synchronous generator has decreased from 252 VAC at zero load to 220 VAC at maximum load and the current has increased.