[Shop-talk] Hot air furnace parasitic loss

[Randall]

> Let's say our transformer is 10cm a side.

That's one heck of a transformer ... mine is more like 4 cm/side.

>  That gives it an 
> area of 1,000 cm^2, or 0.1 m^2.

Not unless your transformer has 10 sides !

> net output is about 13W.

Well, I just measured mine.  Don't have the equipment handy to measure true
power, but the current is only about 50ma; so that's only 6 watts apparent
power.  And the primary resistance is about 35 ohms, so resistive loss is
less than 0.1 watt.

Randall