DIY Arc Light Makes An Unnecessarily Powerful Bicycle Headlight

Remember when tricking out a bike with a headlight meant clamping a big, chrome, bullet-shaped light to your handlebar and bolting a small generator to your front fork? Turning on the headlight meant flipping the generator into contact with the front wheel, powering the incandescent bulb for the few feet it took for the drag thus introduced to grind you to a halt. This ridiculous arc-lamp bicycle headlight is not that. Not by a long shot.

We’re used to seeing [Alex] doing all manner of improbable, and sometimes impossible, things on his popular KREOSAN YouTube channel. And we’re also used to watching his videos in Russian, which detracts not a whit  from the entertainment value for Andglophones; subtitles are provided for the unadventurous, however. The electrodes for his arc light are graphite brushes from an electric streetcar, while the battery is an incredibly sketchy-looking collection of 98 18650 lithium-ion cells. A scary rat’s nest of coiled cable acts as a ballast to mitigate the effects of shorting when the arc is struck. The reflector is an old satellite TV dish covered in foil tape with the electrodes sitting in a makeshift holder where the feedhorn used to be. It’s bright, it’s noisy, it’s dangerous, and it smokes like a fiend, but we love it.

Mounting it to the front of the bike was just for fun, of course, and it works despite the janky nature of the construction. The neighbors into whose apartments the light was projected could not be reached for comment, but we assume they were as amused as we were.

Thanks for the tip, [Nikolai].

39 thoughts on “DIY Arc Light Makes An Unnecessarily Powerful Bicycle Headlight

      1. Well Extreme ultraviolet is ionizing radiation, and it is not common to be exposed to it.

        All UV-C, and shorter wavelength (higher energy), from the sun at ground level is 100% blocked thanks to the tiny ozone layer at the top of the atmosphere. And the X-rays and higher energy levels, are strongly attenuated by the thick layer atmosphere surrounding our planet (unless you are in a high altitude plane).

    1. Now you just have to deal with everyone closing their eyes or looking away, while driving toward you.

      Big rigs in outback Australia (road trains) have impressive lights. They dip their lights for oncoming traffic. If you forget to do the same, some will give you a taste of full power as a warning. While probably not as bright as this, the danger is the same.
      You think laser pointers are bad? Pffffft.

  1. They probably aren’t too far off the mark with the Sun remarks, in fact, they may exceed the Sun’s power.

    The Sun has 1360w/m2 across the whole spectrum reach the atmosphere.
    Their lamp draws 4000w, outputting that energy, taking into account cable resistance and losses from the reflector, and light leakage, they would make a similar or larger total spectrum output.

    1. It’s an erotic nuclear bomb. Who can resist the word “Unnecessarily” and “Powerful” ?
      Here’s dedication of somebody pushing for the “b3st”!

      It’s a thin line between madness, genius and diy, and I am not sure where’s what.

      1. I haven’t seen a mobile searchlight used for advertising in a few years, but the last one I saw was still a carbon arc light. You can tell by the smoke coming from the electrodes.

  2. I will stick with 1100 lumin and it does get attention. An Aldi’s special, for cheap. It’s a work light, flood not spot. The hack was mounting it to the handlebars. If need be I can aim it down and be highly visible 360 degrees, and not in anyone’s eye.

    1. That’s actually a pretty good idea… two of them at different angles and you could dip your lights with a switch as well… if I can find a couple of cheapo flood lights and a battery pack I’ll do that this weekend.

  3. I built an arc lamp once using the carbon electrodes out of a couple of D batteries, ran it off AC using a space heater wired in series with the electrodes as a resistor so it wouldn’t draw more than the 1500W of the heater and blow the breaker :-P Didn’t have a reflector or anything, I think we used a couple of cinder blocks to hold the electrodes, it really annoyed the neighbors :-P

  4. Interesting hack: VERY DANGEROUS NEVER DO THIS etc. I once (only once!) build an HVPS with near lethal levels of output using just a bag of (redacted) with 12V input and a very unusual rectifier arrangement. Unbelievably it worked first time and measured in excess of 2.2KV at the sort of current you get in a domestic microwave.
    Did I mention that this is VERY VERY DANGEROUS and will KILL YOU DEAD if you get it wrong. The only thing that saved me was that I’d put a failsafe inline limiting the resulting shock duration to less than 0.2 seconds.
    Still got knocked out nearly, and I am sure it did permanent neurologigigigigcal damamamage :-(

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