From: Tony Duell <ard_at_p850ug1.demon.co.uk>
>Over here, virtually all large-ish screen TVs have what's called a SCART
>socket. This is a 21 pin connector carrying 2 channels of audio in and
>out (4 connections), composite video in and out (the input is also used
>for composite sync in in RGB mode), RGB input, blanking, etc, and lots
of
>grounds.
Never seen one here. This set does take composite video in and audio in
via jack on front (Sharp).
>I've never seen a monitor with a hot chassis. I know the original 110V
>version of the TRS80 model 1 monitor was (I have the service manual),
and
>had an opto-isolated video input, but surely all more recent monitors
>have isolating PSUs?
Many do, but I was thinking more of TVsets.
>About the worst you'll find over here is some varient of the IPSALO
>circuit (IPSALO == Integrated Power Supply And Line Output, Line Output
>being what we call the horizontal output stage).
Comon config here in smaller or lowend sets.
>With these, the flyback is on the hot side of the PSU, as is the
>horizontal deflection yoke. The horizontal drive signal is
opto-isolated,
>the horizontal osciallator, vertical deflection, video circuitry,
>tuner/IF strip, etc are all isolated from the power line, The EHT to the
>CRT is isolated as well, by the flyback transformer.
>
>Of course these means that one yoke winding is isolated from the power
>line, the other isn't. Adds the 'fun' when servicing these.
Isolation transformer is the only way to live.
Allison
Received on Sat Dec 30 2000 - 21:56:00 GMT