Current transformers
By considering the final application and the purpose, several current transformer kinds are available. Each type has its own specific features, but they all have the same goal: to convert, the input current value in a proportional signal; the accuracy of the measurement depends on the application.
Typically, the current will be the primary current of the transformer, while the secondary winding will be connected to a burden resistance, in order to obtain a voltage signal with the same information of the measured current (see the drawing).
Sirio is specialized in the development and production of three types of current transformers.
- Mains Frequency Current Transformers
- Current Transformers for Measurement Purpose
- Current Transformers for High Frequency Applications
Mains frequency current transformers are used to measure alternate currents at 50-60 Hz, up to 600 Arms.
Main features of mains frequency current transformers
- n: secondary to primary turns ratio, that is the number of secondary turns
- RS: secondary winding’s resistance
- Ip: rated primary current (rms value)
- IS: rated secondary current (rms value)
- fn: optimum working frequency (o optimum working frequency range)
- RC: rated burden resistance
- UOUT: output voltage at the rated primary current and with rated burden resistance
- E: measurement’s accuracy at the rated primary current and with rated burden resistance
- Uis: maximum working voltage primary/secondary
- Up: isolation voltage primary/secondary
