For running a 100-watt fan, you can use either a modified sine wave inverter or a pure sine wave inverter. However, it is generally recommended to use a pure sine wave inverter for most electronic devices, including fans.
A pure sine wave inverter produces power that closely resembles the electricity provided by utility companies, with a smooth waveform. This makes it compatible with a wide range of electronic devices, ensuring efficient and reliable operation. Pure sine wave inverters are particularly suitable for sensitive equipment that requires a high-quality power supply, such as computers, audio/video equipment, and certain types of motors.
On the other hand, a modified sine wave inverter generates power with a waveform that is a rough approximation of a pure sine wave. While modified sine wave inverters are generally less expensive, they may not be suitable for all types of equipment. Some devices, including certain types of motors and appliances with electronic controls, may not function properly or may experience reduced efficiency or increased noise when powered by a modified sine wave.
Since a fan is a relatively simple motor-driven device, it is likely to operate reasonably well with a modified sine wave inverter. However, if you want to ensure optimal performance and minimize the risk of any issues, it is still recommended to use a pure sine wave inverter for powering your fan.