Homebrew PCBs

On 2/25/2016 10:39 AM, rolohar@... [Homebrew_PCBs] wrote:

<snip>

Variacs and autotransformers only have one winding. There is no 
primary/secondary winding
configuration. There is no iron core to facilitate induction between  
the primary and the secondary
windings.
<snip>
Hello--

There's most definitely an iron core in an AC-line autotransformer! 
There has to be because otherwise there would be
no transformer action to step up or step down the incoming line voltage.

As for troubleshooting older "hot chassis" equipment, for safety's sake 
always power the equipment with an AC-line
isolation transformer. If you need to power a 120VAC item from a 240 VAC 
line (or vice versa), you can use
a transformer **with isolated windings** designed exactly for this 
purpose. These are sometimes referred to as
"industrial control transformers".

73--

Brad  AA1IP