WE-CSTLF Current Sense Transformers Würth Elektronik WE-CSTLF Current Sense Transformers are specifically designed for low frequencies, catering to 50Hz/60Hz applications such as power lines. The WE-CSTLF series utilizes laminated core material because it effectively handles low frequencies, ensuring optimal performance and durability even in challenging operating conditions. Würth Elektronik WE-CSTLF Current Sense Transformers operate within a low frequency range from 47Hz to 400Hz and measure currents up to 45Arms. Applications include motor control, charging station distribution, load measurements, and more.