Re: [CAD_CAM_EDM_DRO] Transformer

Ian Wright wrote:

> Does the wire gauge not have any bearing on the voltage the
> transformer will
> work at?

That is essentially correct. The insulation on the wire (and packed
around the coil
forms) predominantly sets the voltage standoff rating, while the number
of turns sets
the AC voltage that winding will accept/produce. You can always run a
transformer
on a lower voltage, but the rated voltage is close to the point where
the core will
saturate, and the iron losses will increase VERY rapidly above that
point.

> Or, in other words, is it only insulation type and 'strength' which
> would maybe prevent you using an audio transformer on the mains? How
> can you
> tell if an unmarked transformer can be used on 240 volts?

The best method is to apply 240 volts to it! It is best to wire a light
bulb of a hundred
watts or so in series. If the lamp glows more than is barely detectable
after an initial
surge, then the transformer is not able to accept that much voltage on
that winding.
This also allows you to estimate iron and some eddy losses in the
transformer.

Audio transformers are wound with many interleaved layers of primary and
secondary
windings to obtain good coupling over the entire range of frequencies.
This requires
extra insulation, and so these transformers end up with extra iron due
to that design.
generally, audio transformers are not capable of the power levels that
would make them
of much interest as power transformers. Of course, the transformers in
the modulator
section of an AM broadcast transmitter DO handle a lot of power!

Jon