%> %> %> I suspect (but don't know for sure) that the accuracy of a transformer is %> the way it performs, relative to it's spec's, rather than relative to its %> history. That is, a _given_ transformer may be extremely accurate once %> calibrated, but the _initial_ accuracy may be difficult to predict.
Yes, that's my understanding also. A manufacturer, for instance, could, perhaps buy two separate batches of cores (for use with one batch of wire) and all of the voltages from the transformers made with the first batch would be extremely close together and all of the voltages from the transformer made with the second batch would be extremely close together, but the delta between the two different transformer batches could vary by as much as 20%. With 10V transformers, for instance, batch number 1 might result in voltages of 9V +/- .1% (just guessing) and batch number 2 might result in voltages of 11V +/- .1% %> Adding %> some calibration mechanism on each board can be expensive, but if you want %> a highly accurate reading of line voltage, you may have to do this anyway. Yes, I expect that a calibration procedure would result in extremely accurate measurements, but would require measurement of the output of each transformer. %> %> Jonathan Malton %> S-S Technologies, Inc. %> Kitchener, Ontario, Canada %> %> "I'm not so arrogant as to suggest that my opinions are corporate policy" %> %> %> Max Kelson [email protected]
