Current transformers are a special application of transformers for an electrically isolated detection and measuring of alternating currents. They are made of a toroid with one winding at a high
number of turns. The conductor which is to be measured is lead through the hole and represents the primary winding. The current in the secondary winding is proportional to the current through the
conductor. This secondary current is measured via the voltage of a load resistor for further processing.
Generally, our CT's are suitable within 50Hz and 10kHz, some types up to 100kHz. Limitation of that is in some cases possible. Measurements outside this area
may work but have to be sufficiently tested by the customer. Maximum drive level rises with the frequency. However at higher frequencies unwanted effects (i. e. distortion) may occur. Since
ferrites are to operate well only at higher frequencies they don't work too good at 50Hz/60Hz mains frequency.
tape wound core (BB)
amorphous / nanocristalline tape wound cores