Re: [CAD_CAM_EDM_DRO] Re: current rating of transformers

Roy J. Tellason wrote:

>On Wednesday 27 October 2004 02:08 am, Jon Elson wrote:
>
>
>>Bloy2004 wrote:
>>
>>
>>>To make it easier this URL will take you to the power supply:
>>>http://tinyurl.com/53ut7
>>>
>>>
>>Gee, I hope they are not positive ground! Note the -48 V @ 25 A.
>>That is real common for the Telcom people, they run with ground
>>and Minus 48 V. If the supplies have a floating output, then they will
>>be fine.
>>
>>
>
>Why would that be a problem?
>
>

If your drives have some common between the negative power and the computer
connection, it would be a BIG problem, possibly resulting in flaming
components
flying about the room! Literally! If you carefully manage the wiring
in a system
where the drivers are totally isolated (it can be done with Gecko
drives, but is
not automatic as the err/res pin is NOT isolated!) then it can be fine.
But, if
you were not aware of this bonding of the + output to ground, and had the
- of the driver connected to computer ground, it could be quite spectacular,
with a 25 A power supply.

Jon