Which type of transformer is used to step down voltage for measurement and control systems?

The type of transformer used to step down voltage specifically for measurement and control systems is the potential transformer. These transformers are designed to reduce high voltage levels to lower, more manageable voltages that can be safely measured and utilized by control devices. This is crucial in various applications such as metering, protection relays, and control circuits where accurate voltage measurements are needed without exposing sensitive instruments to dangerous high voltages.

Potential transformers work by maintaining a precise ratio between the primary and secondary voltages, ensuring that the output is proportional to the input but at a much safer level. They are typically used in power systems to provide a reduced voltage signal for instrumentation and protection devices, enabling system operators to monitor and control the distributed electrical energy effectively.

In contrast, other transformer types serve different purposes. Power transformers are used predominantly for transferring electrical energy between two or more circuits and are usually meant for efficient voltage transformation at high power levels. Current transformers are designed to measure alternating current (AC) by producing a scaled-down replica of the electrical current flowing through their primary winding, and isolation transformers, while they provide safety and noise isolation, do not specifically serve the voltage stepping down function for measurement.