quick system disconnect idea

**d_sellers1** · 05-13-2005, 06:18 PM

I'm designing a system for a friend of mine who has a Honda Civic and would like to be able to remove his entire system (subs, amps, and carputer) prior to going to the track. The theory behind this project is to make some sort of quick disconnect for a system to enable it to be taken out quickly and easily (prime power and ground cables will be on their own stand-alone disconnects). The current system requirements only include a VGA touch screen, slim DVD drive, and perhaps a USB 2.0 drive for media transport. This would require a VGA cable and a USB cable coupled to a USB hub located in the front of the car. For easy installation +5v and +12v connections could also be made through this connector.

D-Sub (VGA) 15 pins
USB 5 pins
+5v (+ & -) 2 pins
+12v (+ & -) 2 pins
--------------------------
24 pins

At least a 24-pin connector would be required. A parallel (printer) cable has twenty-five pins. It is comprised of two rows of pins, which would make soldering rather easy. I imagine a small box with a parallel connector on one side and VGA and USB connectors on the other. The use of a 15-foot long parallel cable would eliminate the need to run individual cables to the front of the car. This would allow one portion of the connector to be located in the center dash (perhaps behind the touch screen).

All this was working out pretty well and all seemed too easy. Well, I just realized that car’s speakers would also need to be added to the quick disconnect along with the ACC line. That just added another 9 pins needed. Now I need a 33-pin connector and a matching 15-foot cable. That is probably going to be a bit hard to find. If all else fails and I can’t find a 33+ pin connector then the next option would be to run a parallel cable along with a D-Sub (VGA) connector. Doing so will kind of take away from the quick disconnect aspect but in the most part, it will be retained. The biggest advantage that I have in this project is the fact that all the wiring will originate in the front of the car.

If I find a 50-pin connector and cable then I may add an additional USB port so the DVD drive will be on its own connection.

Parts needed for this project
2 project boxes
2 female 33+ pins connectors
1 15-foot matching 33+ pin cable
2 female D-Sub (VGA) connectors
2 female USB A connectors (???)
2 4-port speaker terminals
2 2-port speaker terminals (for +5v and +12v connections)

Does anyone see any problems that may arise from doing this project?

Does anyone know of a connector that I should use? (I have not started searching for one yet.)

Does anyone have any suggestions where I should purchase the connectors? I think that is what is going to end up making this project somewhat expensive.

Would it be better to keep both project boxes relatively close to each other and use a shorter connection between the two? This would cause me to reroute the speaker wires near the back and I would need VGA and USB extension cables (and raise the price) but may eliminate some of the cross talk in the 33+-pin connector cable.

Derek

**d_sellers1** · 05-13-2005, 07:03 PM

New information. It looks like I may go with a Centronics 36 connector.

A ten foot M/M cable from Cables2Go is only $1.56.

I was looking at some of the SCSI cables but a ten foot SCSI-2 DM50 cable was seventy bucks. Pass.

Derek

**Change** · 05-13-2005, 07:20 PM

You probably don't want to send video over that, good video cables send the color data through shielded coaxial lines within the cable. I don't know if the Centronix cables are even twisted-pair...

(oh, and to cut down on pin count, check VGA pinouts, I don't believe all 15 pins are used)

**scott_fx** · 05-13-2005, 07:37 PM

i agree with the post above. with that aside, what is stopping you from using two of the quick disconnects? this will get you all you need and wont be that much more time consuming to disconnect.

I would get a bottle of nitrous instead of taking out my system

**Rundell** · 05-13-2005, 07:45 PM

I did a docking port for my entire system I have no problem with video or anything. Docking Port For Entire System

**scott_fx** · 05-13-2005, 07:47 PM

that is pretty slick

**Rundell** · 05-13-2005, 07:50 PM

Originally Posted by scott_fx

that is pretty slick

Thanks! Still need to route power through it, just havn't done it since I ordered the wrong pins for the connector

**PatO** · 05-14-2005, 10:35 AM

I don't know if running power near a/v cables would be a good idea. (interference)
Might want to use a second connector for that, or use a big connector and run power far away from the rest. Make sure your cables are large enough!

The cool thing with Rundell's is that the cables are all seperate - the connector is the only point where they get close to each other. Running all lines through a single SCSI cable might not work out so well...