CW80 voltage measurement

[lionelsoni]

This might be of some use to anyone who needs to measure the voltage out of a CW80 transformer.  I got to thinking about this in connection with Jim's (jaabat's) question about a beacon accessory.  It has gotten far enough from that topic to warrant starting a new one I think, and stop beating the other dead horse.

The usual way of measuring AC voltages is the root-mean-square (RMS, the square-root of the average of the square) voltage.  Any AC voltmeter you are likely to have will measure the correct RMS voltage only if the waveform is sinusoidal.  Unfortunately, the CW80's waveform is not sinusoidal.  So its voltage can be measured accurately only with a rather special voltmeter.

What I have done is to make a table that converts the voltmeter reading of a CW80 to RMS volts:

0             0
 1             2.7
 2             4.4
 3             6
 4             7.3
 5             8.6
 6             9.7
 7             10.8
 8             11.8
 9             12.7
 10            13.6
 11            14.4
 12            15.1
 13            15.8
 14            16.4
 15            17
 16            17.4
 17            17.8
 18            18