New builder: how to derive 5V and 12V supplies for cockpit

[bryn]

Newbie Alert!

I've gradually collected a few Bodmar and Open Cockpit cards and  P&P modules courtesy of this site and EBay but I'm not sure of the best way of powering them (only one P&P module came with a 5V supply.

Do you use a spare computer PSU to supply these units, and if so can you direct me to a wiring diagram or modification instructions to allow me to switch the PSU on and off and to access the individual 5V and 12V buses.  Do you just cut the wires coming out of the PSU or do you use connectors of some description?

This must be a problem that every builder solved on Day 1!

Thanks for any advice.

Bryn

[Trevor Hale]

Hi Bryn

On the computer power supply the GREeN wire on the Motherboard connector connected to ground (the black wire next to the green wire) will turn on and off the psu

If you have a single rail ps isolating the individual supplies doesn't do much.

Yellow is 12v
Red is 5v


No need to reinvent the wheel here. Most of us use pc power supplies

[Joe Lavery]

Hi Bryn

Trev is quite correct we all use PC power supplies, this YouTube video explains it more graphically.

https://www.youtube.com/watch?v=m4uRnID7G_Q

Another option is to buy a ready made breakout board like this one:

http://dangerousprototypes.com/docs/ATX_Breakout_Board

I bought one of these but forgot about it. It works perfectly by the way and doesn't need any knowledge.

Joe.

[xplanematt]

Hi there,

Some other thoughts for you: I used PC power supplies extensively on my original sim, and I would not do it again. They tend to be of questionable quality, certainly nowhere near industrial-grade. PC power supplies also don't generally handle much current, plus they are really made to only mount one way. On my old sim, I've had issues with mounting, occasional resets/failsafe situations (have to shut down the PSU, wait a few seconds, and plug it back in), a couple PSUs have died....and, I don't like the big ugly pile of wires hanging off them.

Of course, you can buy the "modular" PSUs (cables are not permanently attached, they plug in to the back of the PSU), spend big $$$ on higher-end units, and modify them to accept your mounting style, but then you might as well spend the money on a proper industrial-grade power supply that is purpose-built for just the voltages you need (and offers more current, and is easier to mount, is more robust, doesn't run as hot, etc).

My Sabreliner is running off two power supplies, plus a dedicated (low current) supply in my I/O box. Watch ebay....a lot of leftover telecommunications equipment and factory/automation stuff comes up there, in addition to actual aircraft hardware. I picked up a 28vDC power supply that runs off 110v house power but provides 50 amps....!!! My other PSU is actually three units in one. It provides 5v, 12v, 28v, 40, and -12v. The main reason I got it is that the 5v supply can handle up to 120 amps! I needed the power to run all the old 5v indirect lighting in the Sabreliner (about 40 to 60 amps....which would absolutely KILL a PC power supply). I picked up two of these at $25US per. They are built into industrial-grade enclosures, have voltage adjustments, large cooling fans, and the one I'm using right now was easy to mount into the nose of the cockpit where the #2 inverter used to live.

Some ideas....here's a nice 12v unit that's popular with ham radio operators:
http://www.ebay.com/itm/301799041054

A low-current model that provides 12v and 5v....good for low-powered interface boards, and it's tiny:
http://www.ebay.com/itm/190815085529

Another low-current 12v supply, voltage adjustable, small:
http://www.ebay.com/itm/261808937466

Need to run 100+ amps at 5v for OEM lighting on a big airliner cockpit? This one is a beast, AND it has 12v also:
http://www.ebay.com/itm/181336622883

Another 5v high-powered monster, also has12v:
http://www.ebay.com/itm/371493011971

This is just from a quick 5 minute search. I spent several days scouring ebay for my 5v/120a unit before settling on that one. As you can see, the deals are out there. My rule-of-thumb is to try to keep consumer-grade equipment (which covers most PC PSUs) out of the sim as much as possible.

Matt

[727737Nut]

Another gotcha with PC power supplies on top of what Matt already mentioned, Ground Loops.  Cheap to Med priced units are notorious fro ground loop issues in sim pits.
Poor grounding and quality control to name a few.

Rob

[Joe Lavery]

It seems I was wrong we don't ALL use PC power supply's. 

Having said that many of us DO! 

I have a full system with all the back lighting and anything else that needs a 12 or 5volt  supply from 2 surplus PC power units. These have been running for three years without a problem, however I realise that those with more power demands may find this inadequate. I guess it depends on how much power you need in your sim.

Joe. 

[727737Nut]

It seems I was wrong we don't ALL use PC power supply's. 

Having said that many of us DO! 

I have a full system with all the back lighting and anything else that needs a 12 or 5volt  supply from 2 surplus PC power units. These have been running for three years without a problem, however I realise that those with more power demands may find this inadequate. I guess it depends on how much power you need in your sim.

Joe. 

Joe,
What is the backlighting in your panels? LEDs?  I am using real panels with bulbs so as Matt said, our amp draw is much higher. Example, in my overhead that is only 60% done, the 700W PC power supply I am using sucks.  The 5v side drops to 4.2V under load!    12V side drops to 11.6V  Bunch of unregulated crap but for LED panels and repro stuff it  works ok.   Moral, know your system loads before throwing money away
like me. Oh and fyi, my PC power supply has been in 4 sims since 2009  LOL  Still works fun, just not under its new assignment.    This is why we must ask lots of questions before giving advice to someone new starting in this wonderful hobby. What works for some may be a disaster for others.

Rob

[Joe Lavery]

Rob,

I agree entirely, it's all a matter of requirements.

Yes my system has all LED backlighting, and of course I totally understand the need for more power when you're running original gear. I recently bought two real Audio panels and they need 30 volts, so I might have to get something a bit stronger, or convert them to LEDs. Which shouldn't be that difficult, just a matter of de-soldering the bulbs and replacing them on the circuit board with surface mount LEDs

Joe.