Newsgroups: sci.electronics.misc
Subject: Re: S-VHS to scart
References: <[email protected]> <[email protected]>
"PV"  writes:

> I made a mistake yesterday...
> I get a color picture just using the monitor out plug but my problem is the
> same when I want to use the scart : I only get a black and white picture.
> So, do you know which pin from the S-video connector I have to connect to
> which pin of the scart plug?

You might not be happy with just the pinout information, because 
it does not tell all. Here is a longer description of SCART interface
(text is taken from
http://links.epanorama.net/links/videoconnector.html#scart
with permission from the author):

The SCART (Syndicat des Constructeurs d'Appareils Radior�cepteurs et
T�l�viseurs) is a twenty one pin connector plug developed by the
European community and found on the back of most European televisions
and video players. The connector is also known as Pertitel connector
or Euroconnector. The formal description of SCART connector is given
in the CENELEC EN 50 049-1:1989 standard and in the IEC 933-1
standards. 

SCART connector is used in most of the consumer video equipments like
VCRs, TVs and DVD players to hand the audio and video connections all
using some connector. SCART connector supports stereo audio, composite
video, S-video, RGB and some control signals. SCART connector can use
to carry many signal formats, but it can't carry all of them at the
same time. Note that not all SCART connections in all equipment are
equivalent, connectors on other equipments might support more signal
format than others. Originally standardized signal format for SCART
connnector were composite video and RGB. The addition of S-VHS
complicated this interface by requiring the RED and Cvbs pins (15 and
20) to be shared with the Chroma (C) and Luma (Y) pins. Different
pin-configurations exist. Which confirations are available depends on
the video device used. 

Composite video and audio are practically always supported, but there
are lots of equipments which do not support RGB or S-video. For
example some TVs support RGB on one SCART and S-video on other SCART
(in addition to standard composite video format). The supported RGB
signal format is RGBS (R, G, B and composite sync). In most cases,
specialized ICs are used for the SCART interface because of the
complicated switching required. 

Because SCART supports many signal formats, there must be a way to
control what is used. Selection of the input and output signal is then
usually controlled in combination with the control pins in SCART
connector and via setup menu of the machine. SCART has control signals
for example to switch between composite video and S-video. I addition
to this there is a signal for aspect ratio switching from wide-screen
to normal. There is also a control signal for the TV to switch
automatically to view picture from SCART connector. Usually the
switching between S-video and other formats need an user setting on TV
menu or input selector button (some TVs have S-video auto-detect for
this). 

> I have also read that there are different types of scarts, eg that can take
> rgb signals. Does this relate to my problem?

Yes.

There are two pinouts for SCART. The original one supported
composite video and RGB.

A later addition was a new pinout option which supports composite video
and S-video.


If your TV uses the oder system, you can't feed S-video to it. 
If you try this, you get black & white picture. 
To get S-video signal to this kind of TV, you need to convert
it so some format that the TV supports. Generally those are
then composite video and RGB. Going to composite video is
the simpler solution (but here you go the composite video quality,
no bebefit of going to S-video in the first way). Going from
S-video to RGB gives better quality, but is much more complicated
and more expensive.

Conversion from S-video to composite video can be made quite easily:
http://circuits.epanorama.net/circuits/svideo2cvideo.html

Conversion from S-video to RGB is more complicated. 
For this some active electronics (special IC and some power source) 
is needed. Some links which might be of use if you plan to
design such circuit:
http://links.epanorama.net/links/videocircuits.html#converters
http://links.epanorama.net/links/videochips.html#decoder

-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/