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Re: [TCML] Calculating transformer output at lower voltages

I'll second the motion --

A few years ago, I spent an afternoon trying to figure out the windings of a transformer for a bandsaw blade welder. I was using a good Fluke DVM, and getting inconsistent results that were just all over the place.

When I put a 1000 ohm power resistor across the meter probes, all the readings fell into place and sanity was restored. I've found now that Fluke even makes a low impedance meter with an input impedance of only 3K ohms specifically for this purpose.


On 6/8/2012 4:42 PM, Jim Lux wrote:
On 6/8/12 9:45 AM, Gary Lau wrote:
Hi Jim,

I must disagree with your post. The advice is often given to determine an
NST's secondary voltage by feeding 120VAC to the secondary and measuring
the resulting Vprimary, this makes sense. However, having tried this, it doesn't work. There's some very non-linear stuff going on with NST's, even well below saturation. There was a thread on this topic several years ago,
I don't recall the resolution.

I haven't encountered this.. I've measured a variety of high leakage inductance transformers.. although only one NST.
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