> Power supply: regulated vs. unregulated?, And what about LD271 LEDs?
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JayPee |
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Class : Apprenti
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Goodmorning all,
I'm thinking of using a power adapter/transformer to power the LEDs. Now I'm a bit confused by the assembly wizard. What is regulated and what is unregulated?
A USB power adapter converts 230V AC (Europe) to 5V DC and the wizard suggests it's regulated, so no 30% safety margin seems to be needed.
My old router power adapter converts 230V AC to 5V DC as well, yet the wizard suggests power adapters are unregulated. Isn't a power adapter like this exactly the same as a USB power adapter, minus the USB connector?
IOW, should I pick unregulated or regulated in the wizard when using this old adapter?
Also, would anyone be so kind to take a look at this LD271 datasheet to see if it is a suitable LED, given that I file it down to increase the angle. I plan to allow 70mA to flow through it. Would that be a good choice?
Edited by JayPee on 15/08/2013 at 07h25. |
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Stormrider |
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Hi JayPee,
My old router power adapter converts 230V AC to 5V DC as well, yet the wizard suggests power adapters are unregulated. Isn't a power adapter like this exactly the same as a USB power adapter, minus the USB connector?
I think you can only be sure if you measure the voltage .
But a usb-poweradapter doesn't cost that much.You just need one who can provide max. 200mA.
Also, would anyone be so kind to take a look at this LD271 datasheet to see if it is a suitable LED, given that I file it down to increase the angle. I plan to allow 70mA to flow through it. Would that be a good choice?
What happend to your LD274?? |
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JayPeeII |
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Never got to make the one with LD274 and now these LEDs aren't available anymore. However, I managed to create a set up with LD271s in which I let 100mA flow through the LEDs but they seem way too dim on my cam.
I'm using an unmodified Logitech S5500. Earlier claim is that it works: http://forum.free-track.net/index.php?showtopic=39&message=9978
Why do these LEDs appear so dim? Even the simple LED from the TV remote glows bright white on my screen while these appear dimmed blue-ish/purple. I don't get it, their radiant intensity of at least 10 mW/sr at 100mA is by far superior to the SFH485P which has 3.15 mW/sr at 100mA. I do have to stress the fact that my LEDs have a wavelenght of 950nm vs 880nm of the SFH485P.
LD271 data sheet https://docs.google.com/file/d/0B0SYL_DwfgbGN1F4N0cxWTROY0k/edit
SFH485P data sheet https://docs.google.com/file/d/0B0SYL_DwfgbGTlZUZkJBa2FyX28/edit
Edited by JayPeeII on 31/08/2013 at 13h20. |
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Stormrider |
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However, I managed to create a set up with LD271s in which I let 100mA flow through the LEDs but they seem way too dim on my cam.
Did you measure or did you calculate that?
What powersource and resistor do you use?
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JayPeeII |
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Calculated...
5V USB source, LED calculated to use 100mA @ 1.3V each. 11Ohms resistor. Serial construction.
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Steph |
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I do have to stress the fact that my LEDs have a wavelenght of 950nm vs 880nm of the SFH485P.
This could be in fact the reason. The IR-Filter of the Logitech S5500 is very week with the SFH 485 P, so you don't need to modify it. Perhaps not enough for 950nm.
You can try to measure current flow of your mount. You will probably not get 100mA. In this case use a 6.8Ohm resistor. Forward voltage of the LD271 is given with 1.30V (≤1.5V) so you can go up to 1.5V.
What do you use for daylight-filter?
The flobby disk solution do not works for the Logitech when unmodified, because it blocks to much parts of IR-lights.
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JayPeeII |
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I haven't used any daylight filter yet, for testing purposes. Also, I did not remove the IR filter because the S5500 doesn't have any clicks or screws. It's all glued together so I'd have to crack it open...
I will measure the set up to see if it actually is getting 100mA. But Steph, if you look at the graph of the LD271, even 50mA would offer way more mW/sr than the SFH485P? At least, if I'm interpreting the graph correctly.
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Stormrider |
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I haven't used any daylight filter yet, for testing purposes
I think you should try it first with a sort-off daylightfilter.If you block the normal light you can slightly increase the exposure to get your ir-leds more brighter.
I tried my set-up without floppy-filter and my sfh485p are not visible either.
I have a modified ms vx3000 webcan and a floppydisk as an daylight filter.
Did you also choose I420 instead of rgb at the streamtab in freetrack?
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JayPeeII |
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Floppy filters give me a total black out on the S5500. Like Steph also mentioned. So I will have to be inventive and think of something else.
I'm using RGB24. Since you're asking that I suggest you want me to try I420. Will do that now. Hold tight...
EDIT: Check with I420. Same results as RGB24. Background light is much brighter than the LEDs.
Take note though, my conclusion that the LEDs are too dim is based on a regular cam feed through Skype, in which I see a normal image unlike the images RGB24 and I420 mode in FT produce.
My reasoning is that if they are not bright enough without a visible light filter, then they sure will not be bright enough if I start filtering, because filters also take away a bit of IR light if I understand it correctly.
Edited by JayPeeII on 01/09/2013 at 10h50. |
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Stormrider |
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Floppy filters give me a total black out on the S5500.
What if you move the treshold slider in freetrack more to the left?
if you block the normal light you can increase the exposure of your webcan so the leds should be more visible.
What you must try is, apply a daylightfilter, decrease the exposure of your cam until the image apears black or red(depending in the mode you use I420 or RGB) and then try your leds.
just like I said before, I cant see my leds either without a filter.The image is much to bright, I can see everything without that filter.
My reasoning is that if they are not bright enough without a visible light filter, then they sure will not be bright enough if I start filtering, because filters also take away a bit of IR light if I understand it correctly.
Use a filter that blocks just the normal light and not the Ir-leds.
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JayPeeII |
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OK, got it. Any tips for visible light filters besides floppy material? It blacks out everything.
Edited by JayPeeII on 01/09/2013 at 11h04. |
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Stormrider |
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I can hardly see the sun
you are right about that.  But that is just what we want.Block normal light and not the Ir-leds.I know the floppy filter is for some people not the best.But it works for me.Exposed film, vhs-tape?Those you can also use as a filter
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JayPeeII |
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VHS tape, never thought of that! Gonna try it!
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JayPeeII |
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Taped the cam off with 6 layers of photo negatives.
Exposure to 1/30s (higher, e.g. 1/25s limits FPS)
Gain to 10.000 (max.)
Blobs seem visible now but sometimes they get too small/dim when turning away.
Going to search this forum for optimal cam settings.
Edited by JayPeeII on 01/09/2013 at 11h38. |
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Stormrider |
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Blobs seem visible now but sometimes they get too small/dim when turning away.
you can probably solve this by filing down the leds.
this what they say in the handbook
The LEDs fade away when I turn my head only a small amount.
The viewing angle of your LEDs is too small, increase the viewing angle by filing the LED lens tips down flat, almost to the metal part and then make the final finish transparent matte (not too shiny, not too rough).
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