18 May
2010
18 May
'10
5:21 a.m.
--- On Mon, 5/17/10, Randy Dawson <rdawson16 at hotmail.com> wrote:
It may be just simpler to add an isolation transformer to
the monitor, or if its a 'hot' chasis just be sure the
supplies of both systems have no difference in hot and
neutral.?
This is essentially the situation. I've modified a black and white television set to
accept composite video. It was surprisingly simple to do, and the picture is acceptable,
considering the quality of the set. I'm currently running the TV on an isolation
transformer. It's a hot chassis set with a polarized cord. Even though the neutral is
at the same reference as the computer input, you'd run into problems on circuits with
a GFI outlet.
The isolation transformer is ideal in terms of safety, but not in terms of size or cost.
I'm using my bench iso for testing, but I want something I can mount inside the
television, so I won't need extra equipment to use it. Arcade machine isolation
transformers are too big - I'm looking for a smaller/cheaper one, since the power
requirements are minimal, around 30 watts.
Optically isolating the video signal is another option, eliminating the need for the
isolation transformer. The advantage here is low cost and small parts. I was unaware of
the single-chip video isolation solutions, hence why I asked :)
-Ian