Current Transformers, Transducers & Transmitters
Current transformers are devices that are used when a current is too high to process by electronic equipment or to measure by measuring instruments. A current transformer will “step down" the current from thousands of amperes to a standard output of a known ratio to either 5 Amps or 1 Amp allowing small and accurate instruments to be protected from high currents. There are two main categories of current transformers. Measuring current transformers are used with measuring devices for the magnitude of current, power and energy. Protective current transformers are used with protective equipment such as relays and trip coils in magnetic circuit breakers or miniature circuit breakers.
Current transducers are devices that act as an interface between the power system and the measurement system. They convert any non-standard electrical current input into a usable electrical current output, such as an alternating current (AC) input signal into a direct current (DC) output signal. Current transducers operate by magnetically inducing current from the conductor into a proportional electric current that flows through the current transducer’s conductor. This protects measuring devices from high power currents.
Transformer Basics
What is a Transformer?
Transformers take one type of voltage and convert it to a different kind of voltage. The amount of energy being used stays the same. When voltage is increased or decreased by a transformer, the amount of energy is not increasing or decreasing, it is simply changing the way the energy is being used. Ohms law (V=IR) shows that the current will change proportionally to the voltage. Therefore when voltage increases, amperage decreases. When voltage decreases, amperage increases. A transformer can take any type of AC voltage and change that voltage either up or down. For example, power companies use transformers to change the voltage from a very high, dangerous voltage down to a level that can be safely used in homes. In industrial applications, transformers step down voltage from 480VAC to 120VAC to use in control circuits.