CONNECTING LED DIODES

Hi,

I have an issue with some LED diodes with my overhead panel.
I have connected them the same way in my MCP, and all the LEDs light with the same intensity, but not the case on the OVHD.

This is my setup.

1. Single PSU about 300 W, PC has its own supply through a 750W PSU
2. I USB expansion card (OC), powered by the USB cable from PC
3. 3 Mastercards powered by the PSU, each with it's 5 V power from the PSU
4. All LEDs connected without any resistors, directly through the +5V of the Outputs connection terminals ( I have made the outputs terminals, wired correctly and not loose)
5. All LEDs connected to separate outputs connection on the Outputs of the Mastercard (OC)
6. I have connected some LED +5V in a series and then 1 wire going to the +5V of the output terminal, which in turn has 2-3 separate terminals via wires (in order to make room for all the +5v needed for each 5v power).

Perhaps my MCP connection are working fine for a longtime without any burnout or LEds going bad; because they have less LEDs needed, but dunno.

I hope that above is understandable, lol.

Any suggestions would be great and welcome.

Thanks,

Taufeeq

Anyway,

Sorry Taufeeq, this is a Mechanical forum, I cannot help with electrical issues!

Cheers Gwyn (Westozy)
www.aerosimsolutions.com.au

Power the USB output card with +5V from your PSU (just as the Master cards). A USB connection is not able to provide enough current for 64 leds. And put a resistor in series for each LED.

Hi Taufeeq,

If nothing is working then the problem is often quite simple. There will be a poor connection or a fault of some kind, but finding it can be tricky. It could be that you have overloaded the capacity of the Output card so I would go back to square one. If you are certain the LED's are connected with the correct polarity then try this:

1. Remove all LED's
2. Connect just One LED and see if it lights up
3. If it does, connect the next and so on until the fault recurs. You then know the capacity of the card.
4. If it doesn't, you know the Output card is faulty, so check that out

Let us know how you go.

Cheers,

Ken.

Nico, yes good point, I assumed he had the Output card powered off the PSU. The USB port certainly will be insufficient for 64 LED's.

Hi Gwen, Nico, and Ken,

1. Sorry, I seem to always post on the wrong forums, me baad!:(



Nico - if I connect the USB Expansion card with a +5V on top of the USB cable that is powering it, will it not get fried?? The Masters do have +5V going to them, and I have verified that.

The LEDs in concern do light up, but just not with the same brightness as the other LEDs.

If I am correct, without resistors all I am doing is shortening the life of the LEDs, right? Or am I also taking power away from the other LEDs?

I will go home and check all that you have suggested tonight.

Thanks,


Thanks,

Quote:

---

Originally Posted by shoumi

Nico - if I connect the USB Expansion card with a +5V on top of the USB cable that is powering it, will it not get fried??

---

No, it will not: jumper setting and +5V

and do use resistors, if you put +5V of the PSU upon them they will burn...
Nico

Hi Nico,

forgive me for coming back to this - but I have a USB Expansion Card, which according to OpenCockpits should not be powered by anything other than the USB port. Are you referring to the USB Outputs card?
I only have 1 USB EXPANSION CARD and 3 MASTERCARDS.



This is what the moderator wrote on a post at OC.




USB exapnsion information
gianlucag78


Registered to :
21-02-2010

FromItaly

Messages : 1

OFF-Line

Posted 21-02-2010 at 09:16
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Sorry for my bad English but I studied it a long time ago in school.
Checking the site I don't found information on how to connect two or more master card USB expansion.
I want to know how to do and also I want to know what are the 4 jumps ( 3 contac everyone ) that are located between the USB plug and 5Vcc connector
One other question .. even if the USB card is powered by USB, can i connect also 5 volts by PC power or not?
Thank's for your help




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Profile Edit Qoute
support





Registered to :
30-11-2008

Messages : 566

OFF-Line

Posted 05-03-2010 at 16:13
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Hello,

Are you talking about the Master or USBExpansion?

If is the Master, then you can connect 4 Master card to each USBExpansion, because you have 4 connector in this card.

The USBexpansion are independent and can connect as many as USB ports have.

You only must power the Master card, the USBExpansion don't be powered NEVER.

Opencockpits Team.



Opencockpits Team.

Hi Shoumi,
Ah I see, I'm sorry for the confusion. I was referring to the USB outputs card, forget what I wrote.
You do not have to power the USB expansion card, NEVER (like OC wrote)
Nico

Hi Nico,

Thanks;). I will check on the other stuff you guys suggested and report back tonight.

Thanks,

Taufeeq

Well gentlemen,

I officially fried my ATX powersupply, thank god-instead of the OC cards! LOL.

Anyway, I did notice a few things while testing.

1. One Mastercard seemed to have only a few outputs working while I was testing with a LED directly. So, out of the 38 outs, I probably had 8-10 working only. It seems that outputs on that card is no good. The card does not smell like anything burned, and I looked thoroughly to check if the PCB was damaged or something, but looks fine.

Second Mastercard-all outputs worked fine.

2. The ATX Powersupply seemed to struggle a bit as I had 3 mastercards connected with three +5V coming form the PSU. The PSU was 350 Watts, isn't that enough to run a lot of the +5v and 12Vs? What is the minimum I should buy in Watts?
I will have a) 3 Mastercards b) 2 12V cold cathodes and 5 12V LED strips for lighting.

3. My 1st mastercard works like a charm, all LEDS light intensely. However, on the working 2nd mastercard as I kept taking LEDS out, the rest of the LEDs connected to the OUTPUTS got brighter.
I have the +5V connected in a series in batches of 4 to 8, and the individual anodes going to the output terminals.

4. Nico, you have mastercards and OUTPUT cards, any reason why you decided not to use the Mastercard outs?? Does it drain the card and the PSU to use all inputs and outputs and display cards of the MC?

I will get 2 more PSUs tomorrow (just in case) and test again,

Thanks,

Taufeeq