Recent content by kg6gfq

fenix-store
  1. K

    DIY Euro-style Beam Shaping

    I'm about due to build a dynamo headlight. Ideally, I'd like to match the pattern from nicer B&M lights. Something with a fairly consistent brightness both near field and far field, and a cutoff at the top (except some spill to illuminate street signs). That means, if you point it at the...
  2. K

    Simple Standlight - Passive Components

    Yep, the circuit is the one from Post #23. I'll have to wait and see if vibration is a problem. I don't know that I have the soldering skill for delicate SMD work yet, but it sure would be nice for compactness. The Union lens is just what I found at the local Bike Collective, and it's...
  3. K

    Simple Standlight - Passive Components

    Well, here's the finished circuit all soldered up: Side view shows a 1F capacitor on the back - the 2F was just too bulky: The LED and lens are held in place by a 3D-printed backing plate. I forgot to get a photo of the final print, but this test print gives a pretty good idea of the shape...
  4. K

    Simple Standlight - Passive Components

    A higher ESR will result in slower charge/discharge of the capacitor, correct? Are there any other potential disadvantages?
  5. K

    Simple Standlight - Passive Components

    Interesting - I had the impression that 5mm LEDs produced noticeable light at substantially lower current than power LEDs. That could be a result of the integrated optics, though, or just that I haven't spent much time observing the two with that comparison in mind.
  6. K

    Simple Standlight - Passive Components

    Well, this is what I've been running for the past week or so: Voltages were taken with 7 VDC / 0.1A in place of the dynamo, and are pretty consistent with measurements taken on the bike, running from the hub dynamo. D1 is back to being a zener, but when riding fast I've measured point "C" at...
  7. K

    Simple Standlight - Passive Components

    Well, I figured out the problem with D3 - I mis-measured it's Vf. After hooking it up to the fancy power supply at the local hackerspace this evening I found that it didn't start passing substantial current until 1.9 or 2.0V. I also did a quick voltage-current graph for the B&M Lumotec IQ...
  8. K

    Simple Standlight - Passive Components

    That zener in the first circuit was just what I had sitting around at that moment with a Vf near what I thought I needed - turns out I didn't need it to be that high. I just noticed that in editing that second schematic I forgot to indicate that D4 is a Cree XP-E2, not the generic 5mm with a...
  9. K

    Simple Standlight - Passive Components

    Ok... I've done a variety of tests. First, the circuit as shown before, with a 6V DC power supply feeding the rectifier. I gave the capacitor a few minutes to charge before measuring anything. According to the power supply, the circuit was carrying a current of about 0.025A. After...
  10. K

    Simple Standlight - Passive Components

    Well, I'm back from visiting family and the components have arrived. The red Cree XP-E2 with a LEDIL "Flare" optic looks promising on the bench. I am, however, having some circuit design issues. The circuit currently looks like this: I'm testing with a DC power supply, since it's handy...
  11. K

    Standlight circuits (Will this circuit work?)

    I don't know this stuff as well as Steve, but a few thoughts: 1) It looks like the Nicelite bulbs are meant to be used with a voltage regulator that they provide. For a really simple standlight, I believe you could rig up a rectifier, and across its output put a supercapacitor rated for 6V in...
  12. K

    Simple Standlight - Passive Components

    Just ordered LEDs, optics, and other components for a taillight and a headlight with extras left over. I'm looking forward to further experiments! Wow - I'd love to see that! Forum threads aren't necessarily the easiest format to follow, and the early part of the Great Standlight Thread is...
  13. K

    Simple Standlight - Passive Components

    Thanks for the comments! The zener came from this circuit, which I was working with previously. It's good to know that I don't need it. Steve - D4 and D5 are in parallel for optical reasons. A single 5mm LED seemed like an insufficient standlight. As for the front, I might try...
  14. K

    Simple Standlight - Passive Components

    After trudging through much of the old standlight thread, with its various lines of development and numerous missing images, it was a great relief to find the more recent Dynamo lights for Dummies, even if I was out of my depth after the first few posts. Given those resources, I put together...
See more

Latest posts

Top