Circuit for converting spearate sync signals to SYNC-in-GREEN

I found this circuit from news and added this circuit to my WWW page because I got many request for this kind of information. I have not tested this circuit and I provide it here as it is.

From: [email protected] (Peter Stieglecker)
Subject: Howto VGA -> RGB CSync
Date: 12 Jun 1995 13:17:40 GMT
Organization: Vienna University of Technology, Austria
Lines: 75
Message-ID: <[email protected]>
Keywords: VGA,RGB,CSync,Monitor,fixed frequency
X-Newsreader: TIN [version 1.2 PL2]
Xref: sci.electronics:124026 de


A while ago I was asking for a cable, to convert VGA to RGB with Composite Sync on Green. You will need this, if somebody throws away his old graphics workstation and you can get your hands on the 21" fixed frequency flat screen black trinitron monitor and want to hook it tou your Mach64 (don't know if a normal VGA can handle that)

While there is a circuit available on the net somewhere else, this one works perfectly for me and doesn't need any special parts. Please note, that I'm only posting the circuit and didn't 'invent' it, so if you have questions, please mail them to [email protected] directly, since this guy can't read newsgroups very often.

note: german guys, sorry for the english :)

  FAQ maintainers: I think, this thing is the answer to a FAQ :)

             100 uF
          ! !
Green ----! !---------------------------------
         -! !+                                !
                                     680E     !
                     BC548                    !
HSync -------------      __---------/\/\------o---------  CSync on Green
                    \     /!
                     \   /
               1k      !
VSync ----/\/\----------

[note by the poster: for those guys who know exactly as much about electronics
                     as me, BC548 is a transistor, the /\/\ 's are resistors
                     and the 100uF is a condensator. :)

This one works perfectly without _ANY_ logical circuits and thus needs _NO_ 5 Volts or anything else ... ;)

Note: This works only with syncs that are active low, but since this is the default for _any_ sync signal, you would not have to expect any problems with this circuit.

Note2: when you build this with SMD you can put the whole circuit in the VGA connector of the cable. ;)

so long, MadMax. >>>--- for questions contact this guy!

In real Life : Marcus Priesch      Email : [email protected]      
IRC : MadMax on #brezl, #gfrasta   www :
and always remember: don't live for today ... tomorrow will never come !
                                                               (Dr. Shivago)

Peter Stieglecker                    __o     Department of Computer Graphics
email: [email protected]        _o(  ) _ O -------------------------------
phone: +43 (1) 588 01 / 4547     ( )_)(_/_)o Technical University  of Vienna
fax:   +43 (1) 587 49 32       o  \     (  o Karlsplatz 13/186
irc:   PeterGunn ;)             O  ) _  _)   A-1040  Vienna, Austria, Europe
www:                             o(_/ )( Oo  -------------------------------  o  (__)o   (: remotesignature  (c) 1994 :)