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FreeTrack Forum > FreeTrack : English Forum > Support : Tracking System > Wanting to install PS 3 eye + SFH485P IR-LED's (3 DOF)

RSS >  Wanting to install PS 3 eye + SFH485P IR-LED's (3 DOF), What is your opinion on this?
Steph #16 13/06/2012 - 09h22

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This current (50-70 mA)  will go through each LED, which is well below the 100 mA maximum if I'm correct.


Yes, with a 10 Ohm resistance, as long as your power supply do not pass 5,5V you will stay under 100mA:

U = R * I

U = 10Ohms * 0,1A = 1V

3 * 1.5V(led) + 1V = 5,5V

And the voltage over each LED will be 5V/3 = 1,66V correct?


No. You need to drive your LEDs in serie with 1.5V forward voltage, so you have to dissipate 5V - (3 * 1.5V(led) = 0.5V with the resistor.
You determine the tension limit - 70mA:

R = U / I

R = 0.5V / 0.07A = 7.14Ohm

...next  to this value in E-Serie will be a 6.8 Ohm resistor.

But the first light in the circuit would give a higher intensity not and
won't this effect the tracking?


No. You drive your LEDs in serie, so all three passes through with 70mA.
Blackbird #17 13/06/2012 - 13h18

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Great explenation!
I think I understand it now!  :glasses:

So this is the kit I'll be getting (making 2 kits, one for my friend, one for me):
- 10x LED http://be.farnell.com/jsp/search/productdetail.jsp?sku=1212738
- 50x 10Ohm resistors http://be.farnell.com/jsp/search/productdetail.jsp?sku=9341145
- 50x 6.8Ohm resistors http://be.farnell.com/jsp/search/productdetail.jsp?sku=9342206
- 1x Heatshrink http://be.farnell.com/jsp/search/productdetail.jsp?sku=1187634

Will the heatshrink work by putting it around the soldering and than apply heat by a lighter?

What we have got allready:
Hats: Check
Soldering iron and wire (and somebody able to handle it): Check
PS3 eye cams: Check
IR-filter: Floppy disk and/or photofilm
Electric wire: Check

But we only will have the same resistor if his adapter is also regulated at 5V output? I'll give the specifications of his adapter later on! Would the resistors need to change if it has a different currentflow than mine?


Thanks in advance again!
Glad to have so much help  :inn:
Edited by Blackbird on 13/06/2012 at 18h02.
Steph #18 13/06/2012 - 19h38

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Sorry, I do not watch the minimum order value. You do not need to take 50 of them, when you order this one:
6.8 Ohm
10 Ohm
They do the same job.

But we only will have the same resistor if his adapter is also regulated at 5V output? I'll give the specifications of his adapter later on! Would the resistors need to change if it has a different currentflow than mine?



If you take another power supply, that do not have 5V output, you need to re-calculate resistor value.

I do not understand Belgian, but is it right, that you have to pay 25€ postage on Farnell site?

I order from Conrad in France, they got postage between 6-8€.
You got conrad.be in Belgium, have a look if it is not more favourable.

Your articles are:

LEDs
6.8 Ohm
10 Ohm
Heatshrink
Blackbird #19 13/06/2012 - 20h34

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Steph @ 13/06/2012 - 19h38 a dit:

Sorry, I do not watch the minimum order value. You do not need to take 50 of them, when you order this one:
6.8 Ohm
10 Ohm
They do the same job.

But we only will have the same resistor if his adapter is also regulated at 5V output? I'll give the specifications of his adapter later on! Would the resistors need to change if it has a different currentflow than mine?



If you take another power supply, that do not have 5V output, you need to re-calculate resistor value.

I do not understand Belgian, but is it right, that you have to pay 25€ postage on Farnell site?

I order from Conrad in France, they got postage between 6-8€.
You got conrad.be in Belgium, have a look if it is not more favourable.

Your articles are:

LEDs
6.8 Ohm
10 Ohm
Heatshrink



I just noticed that I have to buy at least for 50 Euro at Farnell which isn't the case... I started searching for a new website and I also came to conrad!
I found the LED, but luckily your here to help and sort out the resistors!

Thanks a bunch! ;)
Blackbird #20 13/06/2012 - 20h43

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I've been looking for wire but there are soooo many choices at conrad...
I mean, could you please choose which installation wire would work.
Just has to be basic, but don't seem to find something appropriate.
And would this heatshrink (http://www.conrad.be/ce/nl/product/547552/Universele-krimpkous-TCN20-Zwart-Per-meter-HellermannTyton) be compatible with the wire you choose?

After that I'll order it and start building soon!
Edited by Blackbird on 13/06/2012 at 21h35.
Steph #21 14/06/2012 - 08h55

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You do not have any old PC-data cable or electronic cable for recycling? Like printer or network cable. You can reuse them by cutting of the coat. Just take care to use flex not wire.
Get 3:1 heatshrink.
Take some 3mm to 1mm and 6mm to 2mm to eventually put the LEDs in.
Edited by Steph on 14/06/2012 at 15h47.
Blackbird #22 14/06/2012 - 12h12

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Steph @ 14/06/2012 - 08h55 a dit:

You to not have any old PC-data cable or electronic cable for recycling? Like printer or network cable. You can reuse them by cutting of the coat. Just take care to use flex not wire.
Get 3:1 heatshrink.
Take some 3mm to 1mm and 6mm to 2mm to eventually put the LEDs in.



I've bought everything I need now except for the wire. But I do find a USB cable as powersuply for an old printer. It's about 2m I think. Would this be enough and would this work? If so I'll try and cut it open, but are in that kind of cable even smaller cables that I'll need to work with?

Cheers!
Steph #23 14/06/2012 - 15h57

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I think this will be ok, you will find four flex cable inside good for everything.
Like this:
Posted Image
Edited by Steph on 14/06/2012 at 16h00.
Blackbird #24 14/06/2012 - 17h24

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Steph @ 14/06/2012 - 15h57 a dit:

I think this will be ok, you will find four flex cable inside good for everything.
Like this:
Posted Image



Great! I just cut it up and I do see 4 cables... But still have to remove the outside isolation. I think I'm good to go now! Now it's waiting for delivery ^^
Grtz
Blackbird #25 29/06/2012 - 15h55

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Just to give an update: working will start next thursday  :)
I'll keep you guys updated if need some help, cheers!

Could I just test if the LED's work by connecting 1 LED at one 1,5V battery? Just holding the cables to the poles of the battery?
Cheers!
Gian92 #26 29/06/2012 - 17h47

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Blackbird @ 29/06/2012 - 15h55 a dit:



Could I just test if the LED's work by connecting 1 LED at one 1,5V battery? Just holding the cables to the poles of the battery?



Posted Image  ;D

It's a highly controversial subject but as long as the employed battery outputs exactly or slightly less than 1.5 V it's all right. To be sure use a voltmeter to verify the real battery voltage.

The nominal voltage of a SFH485P LED is 1.5 V and the never exceed voltage is 1.8 V (From Osram/Siemens datasheet).

Be careful when connecting the right poles. A LED isn't like a common light bulb.

Bottom line: it should be OK, but I hereby declare that I am not accountable for responsibilities arising from misuse that could cause damage or injury to persons or property.  :D
Ordem e progresso” - Brazilian flag
Steph #27 29/06/2012 - 18h25

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It's a highly controversial subject...



;D

So let's say nyes... :)
Gian92 #28 29/06/2012 - 19h54

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Steph @ 29/06/2012 - 18h25 a dit:

It's a highly controversial subject...



;D

So let's say nyes... :)



Although nobody demonstrated the obligatoriness of resistors yet; so it sounds as metaphysics to me :)
Ordem e progresso” - Brazilian flag
Blackbird #29 01/07/2012 - 13h59

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:D
Got scared by the picture there  :blink:
So maybe I'll just wait best untill thursday untill some help arives  :inn:
Just in case  ;D

Cheers!
Gian92 #30 01/07/2012 - 14h30

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Blackbird @ 01/07/2012 - 13h59 a dit:

:D
Got scared by the picture there  :blink:
So maybe I'll just wait best untill thursday untill some help arives  :inn:
Just in case  ;D

Cheers!



Ahah, yeah the picture is quite eloquent  :D

Follow Sun Tzu's quote: "If you know the enemy and know yourself, you need not fear the result of a hundred battles."

In this case, the "enemy" is "issues when assembling your device" and "a hundred of battles" is the "result of your assembly" and "use".

I'm not that psychotic, it's just this quote popped out in my mind  ;D

Cheerio  ;)
Ordem e progresso” - Brazilian flag

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