Re: [CAD_CAM_EDM_DRO] gecko's and voltage

JanRwl@... wrote:

>In a message dated 7/5/2003 3:45:18 PM Central Standard Time,
>lux@... writes:
>
>
>
>>I'd like to use a HD 240/120 stepdown transformer
>>
>>
>
>Kim! I can't address your "is that too much?" question as professionally and
>empirically as most others, but ONE thing comes to mind: If this transformer
>is made specifically for stepping-down "European lighting voltage" to
>"American lighting voltage", it may-WELL be just a simple "autotransformer", so it
>will NOT galvanically isolate the secondary and all your expensive and
>carefully-connected lower-voltage DC stuff from the nasty ol' AC mains line, and you
>may-well electrocute yourself, and/or zap a good 'scope, etc., when you try to
>connect the test-lead's "GND" clip to DC (-), etc.!
>
>

No, specifically, a "step down transformer", in the US, is used in
industrial
plant machinery to produce 120 V from 240 or 480 V 3-phase mains to
operate small equipment, such as CNC control computers, lighting,
test equipment, coolant pumps and such. They are true transformers,
and almost always show an actual drawing of the isolated windings.
These transformers are sold by the KVA, and are frequently found in the
several KVA size on the side of salvaged gear.

There are also control transformers used to do much the same thing,
although the output voltage may be anything, such as 24 VAC.
These are usually smaller, rated for just an amp or two.

Jon