Thread: how do i use these PSU's

I will have to post pics later, but basically these power supplies have a female adapter for a plug that accepts the posts that come out of AC-DC converters. (the exact dimensions are ID2.5mm and I THINK 5.0mm - can someone back me up on the last part?) You can buy those posts at Radio shack and then run some wire from the battery for the positive part of the and run some other wire from a ground in the car to the negative part of the post. Then the post just plugs in to the power supply and you're good to go. Really the post just makes it easy to plug and unplug your PSU though, so if you don't need that, you can cut the post female receiver off of the wires coming from the PSU and just attach wires directly to them, but I like the post design.


I should mention this thing does NOT have a voltage regulator on it, so your computer will probably be getting more than 12V, which is a "do at your own risk" sort of thing. There are a number of people here who have reported no problems with this, so you can take that for what it's worth. I have this power supply and will probably be making a V regulator.

Okay - I just looked at my packaging and it's called a DC Power Plug whose Inner Diameter (ID) is 2.5mm and whose OD is 5.5mm.

cool, thanks, pics would be nice cause i still dont know how to run wires or what wires to pull from my truck

Heheh - okay - well, I can tell you the basics of car wiring then. I'm assuming you're very new to this, so forgive me if I tell you something you already know.


The way I've run my system is to run a large wire (8 Guage) from the positive (red) terminal of my battery into my car (Celica) by fishing it through next to the big bundle of wires coming through the firewall under my dash behind my steering wheel column. Then I attached a 30A inline fuse to the wire mainly to protect things in case I accidentally grounded that wire anywhere in the car. See, the negative terminal of the battery is attached to the metal chassis of the car, so most of the time you find bare metal in the car, it's a ground, meaning if you were to touch the positive wire to it, you'll short circuit and see lots of sparks, potentially melt your wire (depending on the guage), etc. So anyway, I took a smaller wire (18guage) and spliced it into the 8 guage wire under my dash, and then ran it through my dash and to my car computer. That end gets attached it to the DC power plug.

Then I attached an 18 guage wire to a bolt under my dash that goes straight into the metal chassis of the car, meaning it's a ground. Note that I also tested this using a multimeter. Basically you can use the multimeter to find out the potential (voltage) between the positive wire you've run from the battery and an arbitrary piece of metal in your car. If you ever see that the voltage is 12V, you have found a potential ground for your equipment. Note again that this is equivalent to running a wire straight to the negative terminal of your battery. Anyway, that wire goes from under the bolt in the dash over to the other terminal of the DC power plug.

Then you can just plug in the power plug to the PSU, and you're good to go. Again, I should mention that many people here feel you should put a voltage regulator in your circuit because your car will put out more than 12V when it's running, which could potentially damage your computer. Do a search for voltage regulator in this forum and you'll see what I mean.

Good luck,

Taylor

do you have pics?