I'm currently working on a project where I'm using a linear Hall-Effect sensor to monitor changes in DC current. This DC current is modulated at anywhere from 15 to 20 Hz. The magnitude is around 125 Amps DC with 5 to 10 percent modulation.
I'm not interested in the magnitude of the DC current. Rather, I'm interested in finding changes in the modulation amplitude.
The sensor that I'm using is working well enough for "proof of concept" but I'd like to get more amplitude out of the sensor.
The obvious solution is to purchase an inexpensive DC clamp-on ammeter and strip it down to only the parts that I need (jaws / clamp assembly & Hall-Effect sensor). But I was looking at some plastic clamps that I have hanging around and it occurred to me that the circular inside diameter of a plastic clamp would hold nicely onto a largish toroid core.
My idea is to find a suitable toroid core and split it such that I have two half-circles. These would be glued into the plastic clamp with the rear split having the Hall-Effect sensor in the gap.
I'm completely ignorant about the magnetic characteristics of toroid cores. Most of the cores that I have seen / worked with are used at various RF frequencies. I'm assuming those are either Ferrite or Iron Powder. I've also looked at tape-wound toroid cores in the past.
I'm looking for guidance in choosing a suitable core. I'll do my initial testing with a substantially-higher frequency (60 Hz) but that's what I have available in my lab. When I have something that seems to be working, I'll take it on site and try it with the actual system it needs to work with.