Red's A-10C Pit

[m0jo]

Interestingly enough, these panels and most all others draw over half an amp current at 5V, so either LEDs will be in order or I'm going to need some large amperage 5V supplies and the proper hookups here in the house to power everything.

Use a computer power supply if you need a lot of amps on the +5V and +12V rail. For exemple, this power supply can have up to 20A on the +5V rail and 18A on each(2) +12V rail. These switching power supply also only cost about 40$.

[Total]

I would shy away from a computer PSU for that task. Computer PSU's are switchmode power supplies that run at a 1/3 duty cycle. The current ratings are for peak current limits and not sustained current.

 

Red, I'll check with a buddy of mine. At one point, we made a surplus purchase of electronic equipment that included some high current +5V PSU's. I can't remember if they were 50A or 100A +5V PSU's. They weren't that large (around 7W X 7H X 14 D), but weighed several pounds each. If there's still one left that we didn't rob the caps out of, I'll elt ya know. He'll probably be happy to get it out from under his feet lol!

[KLaFaille]

Thanks everyone!

 

While it's nice to get more of the panels and things together, I need to start working on the structure to mount these things to! Everything will be built with aluminum so I'm going to have to invest in some metalworking tools and basics to get that going, but that is down the road.

 

I really want to get the throttle finished up and wired to the TM Warthog boards, and then work out the mechanics for the control stick. I'm thinking of using four pillow block bearings, two mounted to a frame that the stick will attach to for the roll axis, then that frame mounted to two others for the pitch axis. Hydraulic dampers will provide resistance and stick centering force. Or could eliminate two of the pillow blocks and use a yoke also. Hall sensors will provide the positioning, and I will likely rip those out of the TM stick base and extend the wiring as needed. The end goal is to have a totally plug and play throttle and stick setup for ease of interfacing.

 

m0jo and Total thanks for the information regarding the supplies. Computer PSUs would seem like a logical choice that I hadn't really considered and I probably have five or six of those stashed away. Total makes a good point though, in that this will be a sustained steady current. A very rough guess off the top of my head, I'm looking at maybe 15A give or take a few just for the left and right console alone. I'm going to play around with some LEDs to see what sort of quality of lighting I can get. A draw 200-300 mA per panel would be a lot better, not to mention reducing heat (these panels do get quite warm) and not having to desolder miniscule incandescent bulbs when they burn out.

 

Let me know what you find out Total, thanks.

 

Those are awesome. Not sure I wanna know what body parts you had to sell to get them though.....

 

Thanks! All I can say is it helps to know the right people when you want to keep all your organs intact. :beer:

Edited July 12, 2011 by KLaFaille

[Total]

Another option is to just make you a few 5V supplies using an LM7815 regulator on each :)

 

Years ago, I worked in research and development on fighter avionics units and we had tried to use LED's in the panels several times. The specification for brightness levels (both dim and full) alongside the power requirements were frustrating as heck especially when we had to have audio amplifiers in the unit. LED's would always meet the full brightness spec, but never really cut it for the dim specification due to the threshold voltage of LED's.

 

Also, the light from the LED's did not behave like that from a small incandescent or even a B1A neon bulb. It just didn't crawl & spread through the lightplates the way "non-green" light sources would.

 

For a home pit though, LED's would probably work out just fine :)

Edited July 12, 2011 by Total

[KLaFaille]

Thanks for the great info again Total. I found it interesting that there was so much difficulty getting LEDs to work properly. Considering the narrow voltage window and the way the current scales in them though, I can see where there might be problems, especially considering how specific the requirements of MIL STDs are. I may play around with it a bit, but it will be hard to match the quality of the light the real panels put out currently.

 

Good call on making some home built supplies, that seems a very good way to go. Just from taking other supplies apart they don't seem terribly complicated and, i'm guessing, it isn't like the bulbs would require some super low ripple high quality 5 VDC anyways.

 

Red

[Total]

When I get back from vacation I can draw ya up a schematic and a parts list. Not too difficult at all and you won't even need to etch the pc board. You can solder everything on a small piece of perf board if ya want :)

 

Right now though, back to watching my wife in a bikini and enjoying the sand between my toes :D

[KLaFaille]

When I get back from vacation I can draw ya up a schematic and a parts list. Not too difficult at all and you won't even need to etch the pc board. You can solder everything on a small piece of perf board if ya want :)

 

Right now though, back to watching my wife in a bikini and enjoying the sand between my toes :D

 

Thanks Total, I'd appreciate that very much. But you definitely have your priorities straight right now! :beer:

 

Enjoy your vacation,

 

Red

[airdog]

Right now though, back to watching my wife in a bikini and enjoying the sand between my toes :D

 

Pictures or it didn't happen

[Kuky]

Pictures or it didn't happen

 

 

:D

[Cali]

Where did you find that pic on the internet Kuky?

[Total]

Pictures or it didn't happen

 

Here ya go - took this about an hour ago without her knowledge. At least I told her I was posting it lol

 

She apologizes in advance for not looking like she's having the time of her life lol

 

Between the increased stress of work last month (lot of stuff going on there) combined with the death of her father who had been living with us for 10 years, she's actually unwinding quite well :)

[Cali]

Sorry to hear that total, saying a prayer for you guys. Been a crazy summer for you guys.

[Kuky]

Where did you find that pic on the internet Kuky?

 

 

don't know.... I just googled for beach and looked through images and ta-da!

[KLaFaille]

Hey everyone.

 

Just a post to indicate that I'm still alive ;) and still working on the pit, albeit slowly. I'm away on an eight month road assignment for work so with all the pit stuff at home, things are progressing rather slow at the moment.

 

I found a proper AAU-9/A VVI to replace the commercial gauge I had, and found a solution to my need for lighting the panels and pit. I picked up a 5V 30 amp power supply for a good price that will have all the current I need to light everything and then some hopefully. I've made a little headway on my emergency panel lightplate, I routed out all the old traces on the back side and removed the 19 original incandescent white bulbs. I'm currently tinkering with green LEDs to light the panel in as close a shade to NVIS Green as I can get. Dunno if I'll use a straight parallel or series / parallel LED array yet. Parallel will end up being 19 150 Ohm resistors soldered to each led, or the series / parallel would be 9 47 Ohm resistors soldered to 2 LEDs in series, with a 150 on the odd LED, have plenty of resistors to fiddle with just need to breadboard it all out and see what works best then mount it all to the light plate.

 

That's about what is going on for now anyways.

 

Red

[Total]

%$#%$#!!

 

I forgot to post that schematic like I promised :( At least ya have a good 5V PS now tho :)

 

I would go parallel man. It's more work, but it's worth it in the end. Let one LED open and you'll have a dead lightplate from that point on.

 

Also, you can always go with SMD resistors and get a one layer etch on the pcb. The lower profile of the SMD components helps alot too :)

[KLaFaille]

No worries total. I got the 30A 5V deal for about 50 bucks so I can't complain too much and it will do what I need it to. What I'm currently working with on the emergency panel light plate are two diffuse LEDs in series with a resistor. There will be 9 sets of these, then there will be the 19th LED by itself with a 150 Ohm. the 9 sets and the single will then all be connected in parallel, so worst case I lose an LED only two will go out. I am going to have to route new tracks into the board to get all my positives and negatives to the same point at the 5V connector. The original lighting was 19 small incandescent bulbs wired in parallel and then all sealed in with this hard white filler. A 1980 emergency panel at it's best.

 

Thanks,

 

Red

[KLaFaille]

[Youtube]qjAHqqNzM1g

 

Fiddling some more with my ADI and powering it up for the first time with a KGS static inverter. The static inverter is taking 28VDC and turning it into 115V 400Hz AC. This is then fed to the ADI, where it goes through the transformer pack with converts the 115V into the required voltages for the internals. The humming is the KGS Inverter and the ADI converter. Next step is to try and work out stabilizing the ball and build some digital synchro interface controllers.

 

I've had three aircraft static inverters for months now, I just finally decided to throw some power to the ADI and see what would happen.

 

Red

[Mike Powell]

There has been an upgrade to the digital-to-synchro project described in Building Recreational Flight Simulators. If this project is the approach you're planning, please check my site for the changes.

[brydling]

If you can get your hands on three synchros and an 115V -> 26V 400 Hz transformer, you won't need a D/S-converter. A D/S-converter is a much more elegant solution however :-)

 

Niclas

[Mike Powell]

Check toward the bottom of this page: http://www.mattssimulator.com/sim_020.htm

 

Matt has been working on simulators for a long time and has tried and implemented quite a variety of interfaces to real A/C instruments.

[brydling]

There has been an upgrade to the digital-to-synchro project described in Building Recreational Flight Simulators. If this project is the approach you're planning, please check my site for the changes.

 

I know of a group of sim builders in Stockholm (Sweden) that have built your DTS-design and said it didn't work, so they said that they made their own design. Could it be due to the transistor that you mention on the news page of your site? Forward biasing of the FET-diode is of course a bad thing, what symptoms did it have?

 

Niclas

[KLaFaille]

Hi Niclas,

 

Haven't talked with you in quite a bit, hope things are going well. I have another ADI that I could strip down for the two synchros and I have a third one I pulled out of a simulator altimeter, and my KGS inverters can natively supply 26V 400Hz. I'd be interested in hearing details about a non D/S solution even if just for reference / educational purposes.

 

Question though. Would the non D/S solution support controlling both the pitch and roll of the ADI ball with just the three synchros?

 

Mike: Thanks for pointing out the update to the D/S project. I also saw that you now posted your board layouts for download which is a big help. I did some pricing last night, if I were to acquire everything that I need for two controllers from DigiKey it'd be about $125, the transformers being about $45 dollars of that. Even when adding the price of the boards being produced the project isn't cost prohibitive at all.

 

Red

[brydling]

Hi Niclas,

 

Haven't talked with you in quite a bit, hope things are going well. I have another ADI that I could strip down for the two synchros and I have a third one I pulled out of a simulator altimeter, and my KGS inverters can natively supply 26V 400Hz. I'd be interested in hearing details about a non D/S solution even if just for reference / educational purposes.

 

Question though. Would the non D/S solution support controlling both the pitch and roll of the ADI ball with just the three synchros?

 

Red

 

Things are going very well! I see that they are for you too :-)

 

I will answer your last question first: Yes, you can controll pitch, roll AND heading with three synchros (one synchro for each channel). It's actually very simple, but you need a stepper motor for each channel. You use the stepper motor to position the axis of the synchro, the synchro will then output true synchro signals corresponding to the angle that it's rotor has. You need to feed the synchro rotor with 26 V 400 Hz for it to work.

 

EDIT: I just noticed that the ADI doesn't have a heading scale. I'm used to the one in the Viggen ;-) You will only need two synchros then.

 

Niclas

[Mike Powell]

I know of a group of sim builders in Stockholm (Sweden) that have built your DTS-design and said it didn't work, so they said that they made their own design. Could it be due to the transistor that you mention on the news page of your site? Forward biasing of the FET-diode is of course a bad thing, what symptoms did it have?

 

Niclas

 

Yes, I believe the transistor was the source of their problem. They generously kept me up to date with their progress. The update is a direct result of their feedback. The symptom was the inverter stage was inverting when it should not.

[Mike Powell]

Mike: Thanks for pointing out the update to the D/S project. I also saw that you now posted your board layouts for download which is a big help. I did some pricing last night, if I were to acquire everything that I need for two controllers from DigiKey it'd be about $125, the transformers being about $45 dollars of that. Even when adding the price of the boards being produced the project isn't cost prohibitive at all.

 

Red

 

I will be posting a revised, but untested, board layout which incorporates the circuit changes.

 

A possible construction revision is to mount the circuit board on short stand offs to a aluminum plate which can be used as a heat sink for the LM1875s. The leads from the LM1875s can be inserted from the bottom side of the board so the 1875s can be bolted to the plate.