MOD GUIDE - Universal RGB-to-YPbPr/Component Circuit & Mod [8/24/2014]

[thesteve]

start right in the center, and you should be close
set the pots for clean white
in this version as the sync is separate, the Y pot adjusts contrast perfectly

[NightWolve]

in this version as the sync is separate, the Y pot adjusts contrast perfectly

I was wondering about that, did you move the Luma/Y pot before the Sync line because of my pointing that out earlier, as the old design attenuates both at the same time, or were you intending to do that all along ? Just wondering if I helped again in any way. Also, I take it that when a 10K pot is centered, it is 5K of resistance on the pins that are on the same side from the center pin ?

Anyway, I'll probably start up my prettified schematic.

[turbokon]

My boards already uses the pots.  I will eventually revise the board layout for the additional sync circuit.

[thesteve]

Injecting sync after the Y pot was to improve stability (eliminate a sync drop on white screen)
The 10K pots center is 5K per side

[turbokon]

Here is the new revised component board layout.  I still need to triple check it again.  Note, original C1 & C2 are removed.  C1, C2, & C3 are at RGB or resistors can be used in its place for more universal application.

[thesteve]

change R18, R15, R11 to 500ohms
increases sync current and picture brightness range

[NightWolve]

Major update is now live!! Steve's circuit design is up-to-date as of 8-23-2014 and hopefully is in what's considered a much easier to understand image form for the masses. This is a free universal RGB-to-YPbPr encoder circuit by a fan for us do-it-yourselfer fans that works with many other consoles as well! I will continue to improve the OP, bring the parts list up-to-date and so forth in the coming days or so.

[thesteve]

change R17 mine, R12 NightWolove to 10K

[thesteve]

better black level, more consistent sync level
fixes picture washout on Genesis

[thesteve]

note it should work fine with 22uf ceramics on the input, instead of the 100uf im running now

[thesteve]

SCART to component converter

[thesteve]

do note that its good sense to put a large capacitor across the power supply input + and ground
i have a 470uf cap on mine

[crans]

@TurboKon

What components are required to add into your existing rgb-comp pcb? Or is it imposable to mod and existing board i have?

[turbokon]

@TurboKon

What components are required to add into your existing rgb-comp pcb? Or is it imposable to mod and existing board i have?

Doesn't look like it would be practical to mod the existing board, too many new components and require some new traces.  The redesign will increase the size of the board significantly unless I go with smaller SMD components which would be harder for me to work with when assembling the boards.

[turbokon]

Another revision to the board layout.