Building a cockpit... need ideas to run lights

Draven · Post by **Draven** » Sun Jun 10, 2007 10:01 pm

Now, I don't 'know nothing about electronics'- I've just forgotten alot of it in the past 17 years (I was a satcom tech in the Army).

Here's the cockpit I'm building- note, this is a full-scale set piece, not a mini.

http://i129.photobucket.com/albums/p235 ... _print.png

Basically, I'm looking for ideas:

how to power the lights? Could I just get an old AT power supply and run off the 5v line?

Most of the switches I'm using are 12v rated switches, and I have some avionics blocks I'm using for drop-in detailing. I don't plan on running power to the avionics because I don't want to have to run separate 24v power.

I need to be able to light 'status' and 'warning' lights to the board labeled warning lights. just like in a real cockpit, 'status' lights are lit solid while 'warning' are either red blinking or solid red.

You can ask me questions, I'll answer them. I just don't want to have to type *everything* about this cockpit if there's only a few simple answers for me.

jwrjr · Post by **jwrjr** » Sun Jun 10, 2007 11:05 pm

A. The output voltages from switching-type power supplies (Like those used in computers) are not reliable unless the outputs are loaded down to a minimum of 10% of the max current draw. All of the outputs. You can still use one if you don't try to caoculate the resistors to max out the led currents. Leave a bit of wirrle room and you will likely be okay.
B. Use bi-color leds (i.e. the red + green ones). Run the green leds for a no-fault condition. To show a fault, turn off the green and turn on the red side (with flashing if desired).

Draven · Post by **Draven** » Mon Jun 11, 2007 12:38 am

Ah well- maybe a 'hobby' psu or something, then...

Sparky · Post by **Sparky** » Mon Jun 11, 2007 3:42 am

yep a 12 volt power supply for HAM radios or car stereos is a good place to start, you might be able to find a 5 volt version too.

A good wall wort power supply will also do. There was a nice one from radio shack, that had multi voltages, I got that one. It is well regulated considering the other wall worts I have.

For blinking indicators I think you will have to pipe fiber optic (plastic kind) in there, and solid cast the instrument panel to eliminate/reduce light bleed.

If you will have a heads up display or large flat panel those work best clear cast and back lit with a white LED (then print your pattern on a decal or transparency).

Draven · Post by **Draven** » Mon Jun 11, 2007 3:49 am

Thanks, sparky, i was hoping you would chime in.

(Remember, this is a FULL SIZE cockpit... 4' 3" tall, 5' 11" long)

There is no HUD (helmet mounted displays) and the MFDs are backlit and gelled green, or printed transparencies, depending on whether or not we need the display to be animated. When animated, they will be a composited effect.

Sparky · Post by **Sparky** » Mon Jun 11, 2007 11:45 am

Why not put some flat panels in there then? Working simulator or something. I hope someone is commissioning this, that has a proper display room. It won't look right next to the family couch

Sparky · Post by **Sparky** » Mon Jun 11, 2007 11:51 am

If you had a computer in there to run the screens, you could put an over sized power supply and tap the 12&5 volt lines for LEDs. The computer provides the load and 4 LEDs in series will happily use 12 volts (you would be slightly under driving them so no problem with a power supply that runs slightly higher 12 volt lines).

I wonder if you could find a test board that fights in a computer and lets you control registers and stuff out of it. I'm sure I've seen some PCI prototyping boards. You could create a program to flash, LEDs and what not.

I'd have to do some searching.

If you start with the PC for the monitor and leave all the LED connections on a wiring harness, adding the fancy functioned PC card for later won't be a major over hull of the wiring.

Draven · Post by **Draven** » Tue Jun 12, 2007 12:38 am

Actually, its for a student film- with the intent of redressing it as needed for later low-budget films.

If we had the budget, we'd run flat panels. I'd actually be looking at getting some laptop 'replacement' displays and wiring them in- I remember somewhere that had adaptors to be able to feed those things power. Flash animations at 1024x768 or 800x600 would make just fine cockpit displays for 720p hi def.

Stealing the 12v lines off the operating PC is a nifty idea, tho...

tetsujin · Post by **tetsujin** » Fri Jun 22, 2007 5:43 pm

Draven wrote:Actually, its for a student film- with the intent of redressing it as needed for later low-budget films.

If we had the budget, we'd run flat panels. I'd actually be looking at getting some laptop 'replacement' displays and wiring them in- I remember somewhere that had adaptors to be able to feed those things power. Flash animations at 1024x768 or 800x600 would make just fine cockpit displays for 720p hi def.

Stealing the 12v lines off the operating PC is a nifty idea, tho...

That is cool! I'd love to see more of this project as it develops.

If your team has some good programmers, one option you may consider for the console displays is old portable game systems. For instance, I've seen some homemade arcade cabinets online that were built with an old Gameboy Advance (screen and main board) built into the control panel, just so they could use it as a programmable display. (They had a PC link that hooked up to the GBA's game link connector, on the PC side all they did was send bitmap images to it, and their custom GBA software would display them) You could use the same kind of link to send whatever program data you want to the GBA and run it. That could work if you have a use for a small in-cockpit display...

These days you could get a used GBA SP pretty cheap - there's also the option of putting in a TV and using that as a computer display (if you don't have TV-out on your PC you could get something like a C-64 DTV game joystick: that thing is programmable, and it has extended modes that let you output 256 color graphics...)

As for power - I would be strongly tempted to go with the bench power supply option if you've got the funds for it, just to have something that's reliable. Whatever you use, make sure you know how much current it can supply at the voltage you're drawing so you don't draw too much power from the supply.

Denise17 · Post by **Denise17** » Fri May 22, 2009 1:19 am

Sparky wrote:If you had a computer in there to run the screens, you could put an over sized power supply and tap the 12&5 volt lines for LEDs. The computer provides the load and 4 LEDs in series will happily use 12 volts (you would be slightly under driving them so no problem with a power supply that runs slightly higher 12 volt lines).

I wonder if you could find a test board that fights in a computer and lets you control registers and stuff out of it. I'm sure I've seen some PCI prototyping boards. You could create a program to flash, LEDs and what not.

I'd have to do some searching.

If you start with the PC for the monitor and leave all the LED connections on a wiring harness, adding the fancy functioned PC card for later won't be a major over hull of the wiring.

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