What is the purpose of a control transformer?

The purpose of a control transformer is to isolate and provide control voltage. In control systems, transformers are critical for stepping down higher line voltages to a lower voltage that is safer and suitable for control circuits, such as those that power relays, sensors, or other low-voltage equipment.

The isolation provided by control transformers enhances safety by separating the control circuit from the high-voltage line supply. This is essential to protect sensitive components and ensure that they operate reliably without risk of high-voltage interference or accidental shocks. Moreover, control transformers can also reduce harmonic distortion and maintain a stable voltage level necessary for accurate control operation.

Options that suggest reducing voltage for power appliances do not apply here because control transformers are specifically designed for control applications rather than directly powering large appliances. Similarly, the idea of stepping up control voltages is counter to the function of a control transformer, which typically steps down voltage. Regulating temperature in circuits is unrelated and pertains to thermal management systems, not control transformers.