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  1. Hirudin

    LEDs wired in parallel, issues with different Vf?

    Yup, we were both right regarding the math. Both come out to a total of 1.54 A and 22.4 V. I wonder if one way is better than the other. Does your way require less resisters/LM317s? I think so... Yeah, that needs 4 instead of 7. Are there other advantages too?
  2. Hirudin

    LEDs wired in parallel, issues with different Vf?

    ...| (-)------------ This array will need a 3.5 V power supply putting out 1500 mA I'm basing my calculations on these pages... LED Circuitry Tutorial and Series and Parallel Connections Hmmm... I think it's possible the voltage and amperage would be the same whether you have 4*(7S) or 7*(4P).
  3. Hirudin

    LEDs wired in parallel, issues with different Vf?

    ...So each leg is 4 parallel wired LEDs that need 3.2 Vf and .385 A each. Add the current together but keep the same Vf and you get 1.54 A (0.385 A * 4) at 3.2 Vf. Then with all the legs wired in series you add up all the Vfs but the current stays the same, so that's 1.54 A at 22.4 Vf (3.2 Vf *...
  4. Hirudin

    LEDs wired in parallel, issues with different Vf?

    Thanks Mash! I'd skimmed through that already, but I'm so green with electronics that a lot of it was over my head. Maybe that chip (the LM317) will work for both regulating/evening each leg like I want AND keep the other legs protected should an LED fail as you want? I'll have to look harder at...
  5. Hirudin

    LEDs wired in parallel, issues with different Vf?

    Thanks greg_in_canada! I don't know much of anything about resisters, but I'll try not to be a typical newbie and go research them myself... These LEDs are going into a planned projector, so even/balanced brightness is important. So, what you're suggesting is to use the highest ohm resisters...
  6. Hirudin

    How to blow away an aspheric mag!

    I have to say, that first shot is one of the most incredible things I've ever seen! Nice job! Good luck with the R2, don't forget to show us pics!
  7. Hirudin

    Where to find clear plastic dome to protect Cree's?

    Surplus Shed has a couple. One's $4: http://www.surplusshed.com/pages/item/m2090.html The other's $17.50: http://www.surplusshed.com/pages/item/m2776.html They take PayPal and have a flat $5 shipping charge.
  8. Hirudin

    LEDs wired in parallel, issues with different Vf?

    ...will make their typical Vf 3.2. The CCHIPO driver has an output limit of 39 V and 45 W. So, if wired in series I'll be limited to 12 LEDs (3.2 V * 12 = 38.4 V). But this will only be using 14.784 W (38.4 V * 385 mA = 14.784 W); well bellow the CCHIPO's 45 W limit. It seems to me that I...
  9. Hirudin

    New Smallest 3W Raw Part 2

    Hmmm.. I think I'll wait 'til the second generation. PS cool knot!
  10. Hirudin

    New Smallest 3W Raw Part 2

    Wow! Cool light! exactly what I want, and more! Tiny, bright, mineral lens, rechargable battery, other stuff! Almost $100 for the whole set though... phew! I would like one, but I'm going to have to justify it to myself first. I've got a couple easy questions... Are there any more pictures of...
  11. Hirudin

    How hot can a luxeon get? How much mA is too much?

    Re: How hot can a luxeon get? How much mA is too m I broke one of mine too, I completely sheered off one of the contacts, I don't think it -could- have been fixed even at that point. I then desided to pry it off the heatsink (to which it was epoxied). Instead of it coming off in one piece, the...
  12. Hirudin

    How hot can a luxeon get? How much mA is too much?

    Re: How hot can a luxeon get? How much mA is too m Thanks everyone for the replies! I should have mentioned that I was using the 6 AAAs (taped together in series) just to power the light now and then, the final light (now finished) is using 3 NiMH Ds with a Fatman regulator board. For those...
  13. Hirudin

    How hot can a luxeon get? How much mA is too much?

    Hi, I'm modifying a 3D maglite to use a luxeon V "portable." I have a heatsink, but I am suspecting that it's not good enough. If I direct-drive the luxeon V with 6 AAAs. The heatsink (suspended in the air by the wires) gets pretty hot in under a minute. I think I'll order a couple hotlips or...
  14. Hirudin

    Multimeter 4.5, RMS, Temp, Sound, Humidity, Lux

    Re: Multimeter 4.5, RMS, Temp, Sound, Humidity, Lu I got mine in yesterday, it's awesome! I don't have a lot of experience with DMMs, but I really think this one will suit my needs. I'll take some pictures of it over the weekend. Oh yeah, is there some kind of -standard- light or something...
  15. Hirudin

    Is there any dummy filler CR123A battery?

    [ QUOTE ] Hallis said: You'll probably end up making a really big resister that way. lol. [/ QUOTE ] Which way? There's four ways there. One of them is only a chapstick case, seems like that wouldn't become a resister.
  16. Hirudin

    Multimeter 4.5, RMS, Temp, Sound, Humidity, Lux

    Re: Multimeter 4.5, RMS, Temp, Sound, Humidity, Lu Oh woops.. I must have either made that up completely or confused it with another or something... sorry guys... EDIT: Ah-ha! I didn't make it up, these guys did: http://www.radios4you.com/dmm-5in1-LG-photo.html I guess it's "3-3/4" I'm going...
  17. Hirudin

    Is there any dummy filler CR123A battery?

    Seems like a dummy battery would be pretty easy to make. How about a dowel with a couple thumb tacks and a wire? A stack of washers if you have a bunch. A chapstick container seems to be about the same size. It's possable a socket (wrench) with a bolt screwed into it could give you the perfect...
  18. Hirudin

    Cost of using rechargable AA's, when to do it.

    Re: Cost of using rechargable AA\'s, when to do it. OK, I admit it, I didn't read everything above, but.. As far as I understand it, NiMH batteries work better than Alkalines in some situations. Something to do with the draw of your electronics, I don't really know. If they do work better it...
  19. Hirudin

    Multimeter 4.5, RMS, Temp, Sound, Humidity, Lux

    I've been looking for a good multimeter for a while now, and I've stumbled apon this one, seems like it could be just about perfect! It's made by Mastech, it's model number is MS8209. The cheapest I've found it is ~$60 shipped. Could this be the ultimate multimeter? I don't know jack about...
  20. Hirudin

    Price, Quality, Brightness, Runtime, Ownership.???

    Re: Price, Quality, Brightness, Runtime, Ownership I own a total of 2 lights, so I wont make a list. But I do get a thril out of having a well-made anything. It could be something simple, like a marble, but if it was perfectly spherical I would like it more.

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