Negative Voltage on PS2 and Xbox

[RARusk]

I am currently in the planning stages of building a Component Video to RGB converter box for use with my PS2 and Xbox. However, some of the chips I plan to use require -5VDC (along with +5VDC) for proper operation. Getting +5VDC is no problem since that can be had at the AV plug. But finding -5VDC is going to be harder.

I plan to make a small plug on the back of both consoles that will send both +5VDC and -5VDC to the converter box to supply the necessary power to operate it.

But I need to find -5VDC. Assuming that it exists on the PS2 and Xbox motherboards where can I find them? Any sources I can go through?

[NFG]

Use a multimeter and probe around the PSU until you find it.  This is one of the easiest things you'll ever do.

Also, the PS2 already has RGB output, as does the XBox, why on earth are you building adaptors?

[RARusk]

For starters, the Component to VGA boxes that I see on the internet don't really support interlaced mode. Plus these boxes do something to the signals that some monitors do not like.

The design involves two triple op-amps for the actual conversion. The sync separation and removal will have the EL1883 at it's core. The EL1883 will be using an auto regulate circuit (created by Intersil - replaces the standard 681K ohm resistor) so it can go between interlaced and progressive signals on the fly.

Since I have a NEC MultiSync 3D dual sync (15Khz and 31Khz) monitor, I can have the best of both worlds when using the Xbox. I can then go from a clean 15Khz signal (at the dashboard) to a nice game of "Halo" (in 31Khz - 480p) automatically.

For the PS2, I can then watch movies in RGB without using a GameShark or DVD Region X to disable the Component Video switchback. Plus I don't have to worry about compatibility problems between the GameShark and the DVD drivers (like I have with Version 2.14). And with the EL1883 also taking care of MacroVision, I have that base covered as well.

However, getting -5VDC is but one option I'm considering. I am also looking for single supply DC restore amplifiers (used for sync removal) and multiplexers (also for sync removal). I already have some EL5444's (single supply op-amps).

Besides, I enjoy hacking and building things. Especially if it works better than everything else out there.....  

[NFG]

For starters, the Component to VGA boxes that I see on the internet don't really support interlaced mode.

For starters you didn't say you wanted VGA, you said RGB.  =P

[phreak97]

i thought i read somewhere that the xbox outputs vga anyway, that means you can concentrate on ps2 only:)

[NFG]

The Xbox does not output VGA.  A quick check on gamesx.com would have confirmed that.

[phreak97]

hmm thats odd.. theres no way to make it at all? i think i read that it was possible on a console with a mod chip in it.. like switching ntsc/pal is.. maybe the guy was getting confused with rgb:/
sorry for any incorrect info anyway.

[RARusk]

You're right Lawrence. I did say RGB.

I found that the multiplexers I have can be operated in single supply mode but I don't know quite yet if that will have a negative impact on the design.

Originally, the Xbox was supposed to do VGA but was disabled at the last moment. I believe this was an attempt to make it harder to use alternative operating systems, like Linux, on the console since Linux works best with a progressive scan monitor. Of couse, that can be worked around by using a Component to VGA adapter and using Linux in 720p mode.

You can get true VGA out the Xbox but it is considerable hack work. You have to hack the BIOS and make drivers for all of the games you own. And worse, you can only do it on some of the earlier versions of the Xbox motherboard. The later motherboards use a different video chip and no one has quite figured out how to do VGA off of that.

[Darklegion]

You might be SOL on getting -5v on either of those consoles,most modern hardware no longer use negative voltage even though pc power supplies still output it.....it is mainly used by some old ISA sound cards I believe.The ATX standard still uses it and the xbox uses the same connector(on the later models)...doesn't mean -5v is actually connected however.I would just check the power supply connectors for it with a multimeter.....may even be written on there.Otherwise I'm not sure of what you can do besided useing single supply chips......there may be a way of converting positive to negative voltage,I seem to remember something along those lines,can't remember where.

[gannon]

You could always build a negative voltage generator off of the normal 5V line. I think that'd be the easiest way.

[RARusk]

I found about several versions of the negative voltage generator circuit. I am also looking at using a PC-style digital-switching no-load power supply to get what I need. Thanks for the responses. I'll let you know what happens later.

[Guest]

... Plus these boxes do something to the signals that some monitors do not like.

This 'something' is quite easy to fix, look at the sync polarity to get your awnser