Current Transformer/Sensor at 60Hz

Triad CSE187L is speced to below 100ma, but not very linear at that level. You can, however, add more primary turns through the core to increase sensitivity and linearity. Mouser & Digikey in stock.

Dave M

Jim Thomps> I need to sense ~200mA AC at 60Hz. Is there a CT rated for such use

Thanks, Dave, That should work, presence above a certain level is all I need to know.

...Jim Thompson

Mebbe a current clamp would work -- you need a one-off or production?

Tek had a dandy current probe with typical Tek accuracy and price -- maybe one of them, or whatever cheap Chinese knock-offs there are out there if you don't need something that fancy.

IIRC the Tek probe used a Hall sensor and an inductor, so it worked from DC to light.

Shunt resistor, clamp diodes and opto-coupler?

piglet

This looks like a winner; just parallel the opto with a resistor that drops 1.2V at 200 mA, and 400 mA AC won't reverse-bias it too much. Resistor only needs to handle a quarter watt. If transients are a problem, add a zener and series limit resistor, on the LED.

You might also consider a too-wimpy current transformer, with a shunt resistor.

Jim,

T60404-E4629-X503 in stock @mouser

Please take a look at

at fig. 20 pp. 26 you will see over all accuracy (phase and amplitude error).

VAC transformer have outstanding performances.

I've designed a Energy meter based on this CT. I realized then phase error is a very important param for class 0.2 and 0.5 devices.

Good luck Jim !

Thanks, Habib! ...Jim Thompson