RGB -> Component DIY

[eddebaby]

Hey,

I'm trying to find a solution that will allow me to use RGB Scart output from my consoles on my Infocus X2 Projector. From what I've worked out it seems the XRGB-2 or XRGB-2 Plus are my best options to convert RGB15khz to RGB31khz.

However I've just found today that there is an updated firmware for my Projector that supports 480i and 576i over a component connection. I've just updated it and it seems to work well for my Xbox at 576i. I'm now hopeful that I can convert my RGB signal to component and It'll work. Anyone who has the same setup - feedback would be greatly appreciated.

Now my question is about this circuit: http://elm-chan.org/works/yuv2rgb/rgb2yuv.png (I've seen a few posts on here but I couldn't find my answers)

* Will I need the circuit centered around the 74HC4053 if I'm not going to be using arcade boards, only consoles (probably only Saturn/PS1 and Gamecube)?
* Is the circuit basically the same as a Cypress CYP-2100?
* I've found the LM6172's for about £2 each, I've got a LM1881N already how much will the components for the power supply be do you reckon? The CYP-2100 is about £50 on eBay so I want to weigh the extra effort and my cack-handedness against the money saved.
* Lastly concerning the LM1881N and the resistor attached to the RSET pin. Is this where you choose the input h-sync frequency (most circuits seem to use a 680ohm resistor)? If so do I need to have it set differently for 480i/576i?

Thank for any help,
Ed

[viletim]

* Will I need the circuit centered around the 74HC4053 if I'm not going to be using arcade boards, only consoles (probably only Saturn/PS1 and Gamecube)?

The opposite, actually. You can remove that part of the circuit only if you are using arcade boards excluseively.

* Is the circuit basically the same as a Cypress CYP-2100?

No idea, never seen the circuit.

* I've found the LM6172's for about £2 each, I've got a LM1881N already how much will the components for the power supply be do you reckon? The CYP-2100 is about £50 on eBay so I want to weigh the extra effort and my cack-handedness against the money saved.

I wouldn't attempt to build that DC-DC converter described. Either build a DC-DC (positive to negative converter) from a buck regulator IC (eg, National Simple Switcher series). Or just build a simple linear power supply instead.

* Lastly concerning the LM1881N and the resistor attached to the RSET pin. Is this where you choose the input h-sync frequency (most circuits seem to use a 680ohm resistor)? If so do I need to have it set differently for 480i/576i?

It's normally 680,000 ohms for normal TV frequencies. I suppose you'd have to fiddle with it if you were working with VGA but I don't think any game consoles have surration pulses in their V-sync anyway...

[eddebaby]

Thanks for the help viletim i'll have a look for that ic as well.

I wouldn't attempt to build that DC-DC converter described. Either build a DC-DC (positive to negative converter) from a buck regulator IC (eg, National Simple Switcher series). Or just build a simple linear power supply instead.

If I take 5v from a usb connection (as my projector has a usb interface) I guess I need to use a positive- negative convertor as you say right?

It's normally 680,000 ohms for normal TV frequencies. I suppose you'd have to fiddle with it if you were working with VGA but I don't think any game consoles have surration pulses in their V-sync anyway...

It should only ever be sent 480i or 576i I think. From what I've been reading my Saturn/PS1/Gamecube won't output a 240p signal directly it always comes out of the console as interlaced. Is that correct? I've only been reading about this for a few weeks once I discovered that I couldn't go back to composite video for my PAL Gamecube. Seeing as no PAL GC games output a progressive signal it was time to finally enable myself to plug RGB Scart signals into my X2.

Edit: I've done the maths (or math if you prefer) on the resistors made of two resistors in parallel. The values don't exactly match so I'm guessing I can construct the needed values with other resistors if I cant find all of the values listed on the elm-chan circuit diagram? Will these suffice? Or do I need something with a better tolerance?

[duo_r]

the original diagram u posted is gone so i couldn't check that. One route I am going is taking RGB signal and feeding that to a Jrok 4.1 Component board. This will convert my signal to component signal. Cost is around $60 USD, I am doing a group buy but I am located in the US.

[Lios]

* I've found the LM6172's for about £2 each, I've got a LM1881N already how much will the components for the power supply be do you reckon? The CYP-2100 is about £50 on eBay so I want to weigh the extra effort and my cack-handedness against the money saved.

I wouldn't attempt to build that DC-DC converter described. Either build a DC-DC (positive to negative converter) from a buck regulator IC (eg, National Simple Switcher series). Or just build a simple linear power supply instead.

I am also trying to build the elm-chan rgb to component encoder, but i am confused on this one point. In the schematic the opamps and that other chip need a -5v. Now you mentioned this would work with a linear power supply, how is this possible? Do I just get a +5v dc adapter (which is what i am using and am assuming is a linear power supply as it outputs only 1 voltage, a +5v) and ground the -5v lines? I'd love to know, as i have the circuit pretty much built except for the -5v ins.