Intro: DVI to ADC Converter
This is my first instructable and although I have no experience whatsoever, I thought that it would be nice to contribute since I have been a frequent user for a long time. I decided about a month ago that a second or third screen would be a nice addition to my computer set up and started looking for something cheap. A few days later I saw on the trash an Apple screen of 17" with something that looked at first like a normal DVI connector, no power input and some USB inputs in the back, so I thought this is my lucky day!
Well, as many of you may know by now, my lack of knowledge was evident as soon as I tried to connect it to my PC and the type of adapter wasn't the same. After a few hours of research starting with basic "converters" I realized that the price range of one of those DVI-ADC was prohibited since it is cheaper to get a brand new screen for less than that.
At that point I was mad because I had a piece of junk in my tiny apartment and I had expend hours learning about the ADC Apple proprietary video connector for nothing.
Well, I did a little bit more of research and found that some people had gone through the same process of trying to make adapters under a budget and went deep enough to figure out tables and pin connections to the detail. However, after some inquiries it was evident that soldering a breadboard and wiring yourself ~30 wires may prove impractical in addition of electrically not recommended since you are going to suffer of noise and such in the near future. Nevertheless, I am thankful for the help of Tony and another instructable, which guided me through the whole process.
the other sources of information came from:
Molex Connectors 1
Molex Connectors 2
The version 1.0 of the prototype is this:
Connected all the pins indicated in the apple datasheet and put a mini AB USB connector (mostly because of the small size) as an interface with the PC. I salvaged a DVI and a ADC connector from an old broken video card and put them to use in my project (that is why they don't look brand new) but they work just fine. Set up the software to control the intensity (only in Windows) developed by some guy, who Tony describes better than me in his blog. After that, connected a DC power supply of 24VDC and at least 1.3Ampers for a monitor of 17" (bigger may require more power...amperes not voltage) and presto!
As you can see in the pictures the PCB is quite small and the most complicated part is the wiring since the pins of the connector are very close to each other and there are not PCB footprints for ADC connectors so I had to design my own. Although, I tried to be very careful making sure the pathways of the power were far from the others, I made a mistake with two wires from the USB that I had to correct breaking the pathways and rewiring them with two external cables. Not the best job ever but as a lesson "don't ever send a PCB layout at 3am". Other than that, the circuit is pretty much plug and play, solder the connectors, connect the cables, connect the power supply and you are good to go.
What is left:
Well, as you can see in the diagram, there is a softpower pin that I left disconnected but it doesn't seem to affect the operation, I have to do some research about it.
A VGA connector will be added in a future version so you can chose if the input is DVI or VGA
I don't know exactly where I am going to put it but the idea of the altoids box sounds good to me for now. Any idea guys?
I had all the connectors around, the only investment was the PCB, Which I had to order at least 4 units and took them more than 2 weeks to send them; each one was like $13. I saw the power adapter on Ebay for something like $11( this would do the trick). Keep in mind that every monitor has different power requirements and the specifications indicate that this adapter (the original apple) can't handle more than 96W (4 Amperes).
Have fun! Ah and let me know if someone is interested in the PCB's that I have left, I think I only need one or two, I am willing to send the other two if you cover the $13 plus shipping.