While the term current transducer is often used interchangeably with current sensor or current transformer, transducers actually perform a slightly different function. A current transducer modifies the input on a primary conductor to a different type of signal on the secondary conductor. For instance, a transducer might take an AC input and modify it so that it outputs a DC signal. In the strictest sense, even AC voltage output devices are current transducers.
So why should you care? It’s critical that you understand the input signal type and the output signal type needed for your application when purchasing. More of our returned merchandise comes from a misunderstanding of this concept than from anything else.
Transducers can operate passively (without external power) or operate actively with external power. There are many different types of tranducers, depending on how they modify the signal.
At Aim Dynamics, we sell the following transducers:
- AC amperage input -> AC voltage output
- AC amperage input -> DC voltage output
- AC amperage input -> 4-20 mA DC output
- DC amperage input -> DC voltage output
- AC voltage input -> 4-20 mA DC output
- AC voltage input -> DC voltage output
#1 can work passively whereas the rest require external power. With #3 and #5 the excitation power typically comes from the DC loop that is created with the meter. #2-6 require some sort of electronic board to convert the signal (often the reason the external power was required to begin with).