Recent content by Peufeu

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    Bicycle Helmet light for cycling

    Hello guys ! I'd have preferred to DIY this, but I don't see how to build a proper waterproof housing... do you guys know any light that would be : - helmet mountable - as light as possible - runs off one 18650 cell (my dynamo system recharges those) - has a red light at the rear...
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    Hello, could you tell us where you got this light ...

    Hello, could you tell us where you got this light : http://www.candlepowerforums.com/vb/showpost.php?p=3436491&postcount=9 Thanks ;)
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    Bicycle Ultimate dynamo light - make a wish

    > Is there any particular reason for the PCB being that huge? Yeah, the PCB has 2x 18650 Li-Ion cell holders, and 1 big capacitor (since dynamo can go down to 10-20 Hz and the flickering is really annoying) which basically determine the size. Therefore, I didn't try to miniaturize stuff too...
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    Bicycle Ultimate dynamo light - make a wish

    > do you have a front rack? No, I don't have the mounting points on the bike. I've had handlebar baskets, but they all ended up breaking, since this method of one-point fastening cannot work reliably... > For a device that large, mounting to the rack would allow a solid > mounting location...
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    Bicycle Ultimate dynamo light - make a wish

    > how big are the batteries, and how big will this whole light system be? It should be able to get you home always, so I set the battery design target to a 4 hour climb at very low speed, not using the dynamo. So, one of those ...
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    Bicycle Ultimate dynamo light - make a wish

    I am also wondering about something -- wether I should split the circuit in two or not. Option 1 : all in the same box, probably located on the front of the diagonal tube of the bike, close to the dynamo and LED. - cons : less room for batteries (2 cells only), not modular - pros : small...
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    Bicycle Ultimate dynamo light - make a wish

    The optics in this philips look pretty good, but the price is just lol. Anyway I just checked the datasheets and the XP-G and Seouls have about exactly the same light distribution versus angle. What makes the difference in beam quality is that the XP-G is much closer to the PCB than the Seoul ...
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    Bicycle Ultimate dynamo light - make a wish

    Yeah, but since it's a bit violent I use it mostly at intersections, when the guy should yield, that makes sure he sees me. Also I've noticed bright clothing gets you more respect during the day. Originally I wanted to put everything on top of the front wheel, but after some tests it appears...
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    Bicycle Ultimate dynamo light - make a wish

    With the same lens the XP-G gives a wider beam than Seoul, and with some lenses, better, with others, worse. I've bought an assortment of lenses. Up until low I have tested them for like 10 minutes so I can't give you precise details !... Also where you mount the light has a lot of importance...
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    Bicycle Ultimate dynamo light - make a wish

    Yo guys. I'm fed up with my battery powered lights : the battery is always dead at the wrong time, it's heavy (especially the helmet light one)... I want a light that's always ready no matter what, even below 0°C when batteries give up, or after a few days of camping with no power to charge...
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    LTC3780 Driver

    Photos of the helmet mounted light : http://audio.peufeu.com/node/67 With 3 lights in series I will need to replace that 0.1 ohm current sense with a 0.03 ohm as it was originally intended. A bit above 6 watts, the chip's overcurrent protection trips because the resistor value is too...
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    LTC3780 Driver

    I put the thing on my website : http://audio.peufeu.com/node/66 I made a little efficiency measurement, it performs according to spec, between 90 and 95%. I couldn't find a 0.033 ohm resistor so I used a 0.1 ohm instead for the 3780's current sense control, so this limits maximum power and...
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    LTC3780 Driver

    There was a minor error in the Linear app note (you have to connect STDBY and RUN for the regulator to start). Apart from that, once soldered, it worked nicely. Dimming too. Of course it's totally overkill, but I like it. Overkill is especially the 4 layer board, but I had to order some for a...
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    LTC3780 Driver

    Boards should arrive in a few days, we'll see if it works ;)
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    LTC3780 Driver

    Hm, I think I prefer the FDS8878, lower RdsON, lower price, lower capacitance, lower gate charge (and of course, lower voltage and current but it's OK in this application). The driver needs mosfet with low gate capacitance or else it'll overheat as you say. Can you give examples of inverting...
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