A useful addition to your toolkit
Jeff Liebermann wrote:
On Tue, 7 Mar 2017 09:11:34 -0000 (UTC), gregz
wrote:
I used to like using a Tek Hall sensor probe. I liked it checking DC shorts
on boards.
Greg
Yes, but have you seen the prices?
http://www.tek.com/current-probe
The cheapest model that does DC is $1,600.
I rolled my own. I took an old Honeywell SS495A Hall effect sensor,
built a suitable amplifier, hot melt glued it to a piece of plastic,
and calibrated it by shoving DC through various PCB traces. It's
ugly, not very sensitive (3mv/gauss or 30uV/uT), and goes nuts near
magnetic fields from xformers, inductors, steel mounting brackets,
wall warts, etc. However, it's cheap and easy. I don't use it for
troubleshooting very often.
The original suggestion sounds much like an RF current probe.
http://www.lowfer.us/k0lr/currprob/currprob.htm
https://interferencetechnology.com/the-hf-current-probe-theory-and-application/
However, these cannot be used to measure current though a PCB trace.
I was using a NASA owned probe. Thought about trying to make one.
Greg
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