Current Sensing

Current transformers accurately sense and measure current flow in power supply circuits in a non-invasive way. Ideally, they shunt a very small sample of the current to measure while dissipating minimal energy. The sensed current information is typically used to prevent overcurrent conditions and to monitor and control circuits in power supplies and other powered applications. Current sensors are frequently used to measure and control the load current in power supplies, safety circuits and a variety of control circuits. In applications where controlling the current is required, such as in power supplies, accurately sensing the magnitude of the current is a fundamental requirement. Coilcraft manufactures wire-through-hole current sensors and SM current sense transformers for measuring current at frequencies from 50/60 Hz to greater than 1 MHz. 

Selecting the appropriate current sense transformer for your application begins by determining:

1. The maximum current to be sensed
2. The frequency of the current waveform to be sensed
3. The duty cycle of the current waveform to be sensed
4. The desired output voltage across your terminating resistor

Selection is greatly simplified with our Current Transformer Selector tool.  This online resource helps you quickly find the best current transformer for your application and includes behind-the-scenes flux density calculations to assure your selection is sized correctly.  Our Selecting Current Sensors and Transformers application note discusses the technology and applications of current transformers.