RSS
Will writes -
"Ok, so here is the scenario: working with CCTV cameras a lot you find that most of your pro-sumer nightvision cameras run on 12VDC. Turns out that all the commercial solutions for distributing 12VDC are limited to 5 amps. Not a whole lot of juice when you are wanting to drive 16 cameras a 500+ milliamp.
After brainstorming on how to build a better system (and more stylish) I realized that a 400 watt PC power supply could kick 15 amps and keep trucking. That was the kind of power I was looking for, almost a full amp per camera if I needed it.
With that in mind, I chopped open a power supply I pulled out of a computer and I quickly came to realize this was going to be easier than I thought. Paying attention to where the yellow and black wires attached to the power supply's circuitry I began hacking at the wires, removing them all." Thanks Chrome Ghost - Link.
I suggest using Anderson Powerpoles for the power connections. They're rapidly becoming a standard for 12v power connections. You can't connect them wrong (even by accident), they use the same connector for both sides of the connection and they will handle much more power than an RCA connector. The 15, 30 and 45 amp versions all use the same housing. I get mine from http://www.powerwerx.com/ (no connection; just a satisfied customer).
Reply to this comment
I think Will lucked out with his choice of power supplies. The vast majority of ATX supplies require a load on the 5 volt rail to provide stable voltages on the other rails.
I used a resitor and installed a cigar lighter socket in one I recently built:
12 volt PC power supply conversion
Jake.
Reply to this comment
A PC-based DVR could supply the cameras as well using this method.
Reply to this comment
Jake is right. I was using an Allied 300w power supply when I did this and it is fortunate enough not to need a load on the 5v line. That can be fixed by hooking a 10k ohm 10 watt resistor to the 5v (red) line.
KWillets - That's an excellent idea. I'm gonna have to try that next, although some sort of breakout would be necessary since 32 18ga wires coming through the back of the PC would be pretty messy. I've also thought about using a 25 pin d-sub to molex thing but we'll see.
Reply to this comment