How many coils (or windings) does an isolation transformer consist of at a minimum?

An isolation transformer at a minimum consists of two coils or windings. The primary winding is connected to the input AC power source, while the secondary winding provides output power to the load. The crucial function of an isolation transformer is to separate the output from the input, which enhances safety by reducing the risk of electric shock and isolating sensitive equipment from electrical disturbances.

This two-coil design helps prevent direct electrical connection between the power source and the load, allowing for voltage conversion (if designed for different voltages) while maintaining electrical isolation. In applications where user safety and equipment protection are paramount, the presence of two distinct windings is necessary to achieve the intended isolation effect.