Posts tagged ‘light’

Blendwirkung V2 – The Uetliberg descent bike light

Blendwirkung V1 was a road light, that was built based on a Luxeon 1 LED (which was relatively new back then in ~2005). I have used it for a while, until I’ve decided that it was just too big and heavy.

Many years later, after I’ve moved my Magicshine from the handlebar to the helmet, and added the beautiful Lux-RC / Easy2Led Light to the handlebar. I began to think about a cordless solution on the helmet, as I really didn’t like the battery in the backpack, running a cable to the helmet. I’ve decided to go old school with this, and use NiMH, as I don’t want any LiXX battery on my helmet. This could be paranoid, but I just don’t like the idea at all.

 

 

I only use this light for the descent of our weekly Uetliberg-Run, so runtime wasn’t a big criteria.  I just wanted high output for about 20minutes on the existing 2/3 sub C NiMH cells that I’ve had lying arround. In the end I went for these components:

  • 2x Nanjg 110 Boost driver, ~950mA each – so Output is almost 2A
  • 1x CREE XM-L2 T6 4C LED – this is warm white, you gotta love it in the woods.
  • 1x TIR Optic, it’s either 20 or 25 degree, I don’t remember.
  • 2x 2500 mAh Sub-C NiMH high power cells.
  • Various Alloy sheet + part of an old heatsink

The light pulls arround 6Amps from the battery, which makes it difficult to find a good switch, since the one I initially installed was fried after about 10 toggles, I’ve removed it and don’t have a switch at the moment. It’s no beauty, but its brighter than most other lights I’ve seen on the Uetliberg, and it was most likely the cheapest as well. Have been using it many times – still love it. This light cannot be used stationary, as it needs some air flow to keep the temperature down.

Hugsby P31 Disassembly / Driver replacement / All flood MOD

In case you’ve ever wondered how to disassemble the Hugsby P31, here’s how it goes:
IMG_0956 IMG_0959 IMG_0960 IMG_0961

I did that because of a malfunctioning driver, and while i was at it, I’ve replaced the reflector with an all flood TIR lens. This makes the little Hugsby a perfect near field flashlight.

Yet another Lux-RC / Easy2Led bike light

Training off-road during the colder days often also means that it’s getting quite dark. There are lots of bike lights on the market, most of them are either too expensive or not 100% satisfying. There’s however a simple solution using components from Lux-Rc and Easy2Led.

Lux-Rc light engine:

A small board, 3 leds and a boost regulator is already integrated, different configurations are available

Easy2Led light housing:

A good fit for the L33X light engine from Lux-Rc, in addition you’ll need a handlebar mount (Lupine or the Chinese equivalent that can be ordered at Lux-Rc), cables, battery, a momentary switch.

Battery:

Input voltage depends on the light engine, mine is optimized for 2s Li-Ion batteries, I’m not going into detail about building a Li-Ion battery pack. This is dangerous, and you should know what you do, or better leave it. My battery pack has some additional heat-shrink tubing over each individual cell, heat shrink tube over the whole pack, and then a layer of plastidip liquid rubber on top of the heat-shrink tubing. Additionally, I’ve added some foamed rubber on the side that touches the frame when the Pack is mounted to my bike.

Oh yeah, and please use a little less thermal glue, maybe 1/3rd of what I’ve used should be enough.

Balancing the Magicshine MJ-836 Bike Light Battery

There are many reports about unbalanced Li-Ion cells in Magicshine Bike lights. This can lead into overcharged cells, which is dangerous, or at least will damage the cells. The charger which comes with the light does not have any balancing capabilities, the battery itself only has some very limited under/over voltage protection.

To solve this problem, you’ll need to modify the battery (add a balancing connector), and use a different charger, or external balancer. I’ll use my hobby charger, which has an integrated balancer.

This is no complete guide, it needs common sense, and some knowledge about electronics. You should also know, that working with Li-XX cells is dangerous.

If you don’t know how Li-XX balancing works, please read:
http://scriptasylum.com/rc_speed/lipo.html
http://www.rcgroups.com/forums/showthread.php?t=599316
before starting to modify your battery pack.

Adding the balancing connector:

Open up the pack:

The interesting part is the four 18650 cells, remove the top of the pack (shown on the left):

Add a new wire which will end as your balancing connector, this is connected to the “middle” of the pack, the pack is 2S2P.

Your Magicshine Pack should now look like that:

The next Step is to put back the isolation, and bring the balancer wire out of the case. this can be done through the original cable exit:

I’ve added a 2mm banana connector, some heat shrink tube, and a cable tie:

Finished Pack, charging:

test

As you can see, the connections were made as follows:

– from the battery goes to – of the charger, and pin1 of the balancer.
newly made balancing wire goes to pin2 of the charger
+ goes to + of the charger, and pin3 of the balancer.