I always thinking of is that possible to use my PSOne LCD monitor to watch video without using Playstation (in fact, I don't own a playstation console). For the last few weeks, I have been working on this project. It took me few days to understand those video signal format and standard, then somehow I visited a great site that has an electronic circuitry to convert PAL signal to RGB signal (PAL to RGB decoder). Then I at once ordered those parts that need to be used in this circuitry. The hardest part of building this circuit is that, since I am not an expert on electronic, making a PCB took me 3 trials. But at last, I have made no mistake and successfully built it.
The first time firing up the LCD and the circuit, the picture was not sync properly (no matter what). Then I think and think, the system was not sync properly may be because I use a composite video signal (contains RGB+CSync) to feed into the LCD, instead of a pure composite sync signal (without RGB data). Then I search on the Internet and found some site that talks about using LM1881N video sync separator IC. Then I ordered this IC and integrated with the PAL to RGB decoder. At the second time fire up the LCD, there a few wiggles in the middle of the screen, but the picture is clear and it sync a bit better than the first time. This little wiggles are not nice, I have to get rid of it, then search again on the Internet, and come across a site that talks about if the power supply is not stable, it may affect the sync of the picture. Then I made another board to regulate the power which is going into the LCD and all other electronic circuit.
Finally firing up the third time, guess what I have got? A nice and stable picture directly from my DVD player on my PSOne LCD monitor. There is still a bit problem that if I use VCR instead of DVD player, there is a wiggle on the top five lines (I guess), it seems like the signal coming from the VCR is not as pure as the DVD player. May be some filtering need to be done.
Here are some of the screen shots of the final product. (excuse me that I use my webcam to capture these image).
Board and LCD
Here is the image of the boards that used in this project, the left side one is a video sync separator board (it take input directly from the DVD player), the middle board is the PAL to RGB decoder, the right hand side one is the regulated power supply board in which it takes (12V DC unregulated power from normal transformer that you can by in supermarket.
Now this image show the final product in action. You can see there is a bright spot at the right bottom, that is because I didn't peel off the protection plastic... hehee
Here is the connection diagram for the above 3 boards, make sure that you are using a large heatsink for the voltage regulators (I use a socket7 CPU heatsink and fan), this is because the LCD monitor requires 7.5V 750mA and I am using 5V 1A (7805) regulator, thus the 5V regulator is running very hot. The 8V regulator you can use 7808 and those boards that use 8V require very less current anyway, so the 8V regulator heat dispose issue is not a problem.
Video Sync Separator 2 - also with Toshiba TFD50W32-B2 pins out diagram
Someone recently emailed me about converting the PAL to RGB decoder to accept NTSC signal, I am not an expert on electronic, but as what I can see and read from the TDA8362 video decoder chip's datasheet, it is very easy to convert it to accept NTSC instead of PAL. All you need is a 3.579545MHz crystal and take out the original one that stayed in the German website circuit diagram and re-wire the connection as stayed in the TDA 8362 datasheet. You don't have to change any other electronic component. Note that I haven't tried this yet, there is no guaranty that it will work, but I belief that it should be fine.
In this project, I have altered the original PAL to RGB decoder PCB layout, in which I took out the power supply section and build my own power supply. This is because, the original one is targetting for sharp LCD module, and it has a DC-DC converter. This converter is not useful for PSOne LCD monitor, so there is no point to include it in the PCB, and that is why I have a separated power board for this project.
At last, if you have any comment, please feel free to email me on trojin100@yahoo.com
All the information and electronic circuitries used in this project are belongs to the original owner (please respect to their copyright), I do not take any responsibility of any matter, do it with your own risk.
Copyright 2002 all right reserved. Wallace Lee