How to find the right Current Sensors AI guide
Written by an AI model from its trained knowledge.
What the AI looks for in Current Sensors
- AC, DC or both
- Current transformers (CTs) measure AC only. Hall-effect or shunt-based sensors are needed for DC. A CT on a DC line reads nothing.
- Isolation
- Use isolated Hall-effect sensors or CTs on mains or high-voltage lines. Reserve shunt monitors for low-voltage circuits sharing ground with the controller. Non-isolated shunt sensing on mains is a shock and damage hazard.
- Range and resolution
- Choose a full-scale rating near your maximum current. A sensor rated far above your load measures small currents poorly.
- Output type
- Check whether the output is analog voltage, I2C (e.g., power monitor ICs), 4-20 mA, or 333 mV / milliamp CT secondary. Some CT outputs need a burden resistor or a specific meter input.
- Form factor
- Split-core sensors clamp onto existing wires without disconnecting them; solid-core sensors require threading the conductor through. Split-core sensors make retrofit installs practical.
Brands that matter
- Allegro MicroSystems: Integrated Hall-effect current sensor ICs; check for newer replacements of older parts.
- Texas Instruments: INA-series shunt current/power monitors with I2C output.
- LEM: Industrial isolated current transducers.
- Honeywell: Industrial current sensors.
- YHDC: Common split-core CTs used in energy monitoring projects.
- Melexis: Hall-based current sensing ICs.
What to avoid
- Measuring DC with a current transformer.
- Open-circuiting a current-output CT secondary while the primary is energized.
Questions
Why does my CT read wrong when clamped around a power cord?
Live and neutral cancel out. Clamp around a single conductor only.