TriLux Bike Light

[andrewwynn]

you got it re: how to set trimpots.. you don't really need the parallel trimpot if you have a 10k audio and a 10k resistor, but it's not a bad idea either.. i htink since i just used a 10k resistor my max output was limited to 950mA vs 1000. ... log/audio taper is an absolute must.. it's nearly useless/pointless to try to dim light w/o audio taper.

the low output .. it's very nice to have 'mood lighting'.. say you get to your destination you can have light all night long at 50mA.. but it's imossible to set with a pot that has no minimum trimmer..

-awr

 

[Steve K]

Nice one!!! Looks great... :rock:

This is what I came up with, running 14w from my dyno hub...

not to detract from the TriLux, but I'm intrigued by Ktronik's light. Specifically, what did you do to get 14W from the hub dyno??

I've got a Schmidt hub dynamo, and have looked at its behavior to figure out how to get more power out of it. At any given speed, the maximum power out is achieved by using less than the typical 0.5 amps. Figuring out where that maximum power point is located is the trick, as well as figuring out how to adjust the load's behavior as a function of speed.

One approach is to simply switch more leds in series as the speed goes up, which is probably the most practical method. Was this used for this light, or does it use some truly clever approach not heard of before???
Mr Bandgap and I have traded a few ideas back and forth, and he has put together a nice circuit that switches a second incandescent bulb in series with a first bulb when a speed threshold is reached. I'm always intrigued by new ways of attacking this problem.

thanks,
Steve K.

 

[greenLED]

Sawtooth, what's that attachment you're using to secure the light to the handlebar? Any links, please?

Nice job on the mod!

 

[Banshee]

NITERIDER UNIVERSAL HANDLEBAR MOUNT

http://www.jensonusa.com/store/product/LS701Z00-Niterider+Universal+Handlebar+Mount.aspx

 

[ktronik]

not to detract from the TriLux, but I'm intrigued by Ktronik's light. Specifically, what did you do to get 14W from the hub dyno??

I've got a Schmidt hub dynamo, and have looked at its behavior to figure out how to get more power out of it. At any given speed, the maximum power out is achieved by using less than the typical 0.5 amps. Figuring out where that maximum power point is located is the trick, as well as figuring out how to adjust the load's behavior as a function of speed.

One approach is to simply switch more leds in series as the speed goes up, which is probably the most practical method. Was this used for this light, or does it use some truly clever approach not heard of before???
Mr Bandgap and I have traded a few ideas back and forth, and he has put together a nice circuit that switches a second incandescent bulb in series with a first bulb when a speed threshold is reached. I'm always intrigued by new ways of attacking this problem.

thanks,
Steve K.

OT: Please post on my 14w dyno page so not to hyjack this post..

Load matching is the key...

The maximum power is achieved at a specific load current. This depends little on the speed, but mostly on the dynamo. In other words: A dynamo is a current source.

This guy did most of the hard work...

load matching

dyno circuits

my post w new pics

I just used his circuit for the shimano hub...have not tested with SON...

This is a voltage dub circuit & full wave rectifer circuit...

Just make the full wave bit to start, use it to find the sweet spot for your hub...

I would like the data you come up with, so if I can help, please let me know...

I can make you a circuit if needed...

I also have the PCB for the auto switching unit...

Try 3 & 4 leds in series... I have moved to 3 leds in a trilux config, better @ slower speed...

 

[Steve K]

hey Ktronik, where's your 14W light page??

to minimize the hijacking already in progress, let me offer these quick comments:

1. it looks like a cap is added in series to the dynamo output to match the load's complex impedance to the dynamo's.
2. ummmm.... what were my other comments? I liked the links you provided. Interesting stuff.

I've discussed the idea of matching complex impedances with other folks, and was told that it works, but is only effective over a narrow range of speeds. I haven't tried it myself because I have some 14% grades to grind up, and need good performance at 5mph as well as 18mph.

Adding loads in series as the dynamo speed increases is a more conventional way to get more power out. For a multi-LED arrangement, it would be great to switch each led in at a separate speed. Kinda complicates the electronics, though...

I think my biggest question was: where's the 14W led light?? The schematic showed 4 one watt leds, right?

FWIW, I'm using a 5W Luxeon with my Schmidt dynamo. Works darned nice! Some paralleled leds are added in series for the taillight, and it pretty much meets all of my needs.

okay.. that's enough out of me! Back to the TriLux talk.....

Steve K.

 

[ktronik]

hey Ktronik, where's your 14W light page??

to minimize the hijacking already in progress, let me offer these quick comments:

1. it looks like a cap is added in series to the dynamo output to match the load's complex impedance to the dynamo's.
2. ummmm.... what were my other comments? I liked the links you provided. Interesting stuff.

I've discussed the idea of matching complex impedances with other folks, and was told that it works, but is only effective over a narrow range of speeds. I haven't tried it myself because I have some 14% grades to grind up, and need good performance at 5mph as well as 18mph.

Adding loads in series as the dynamo speed increases is a more conventional way to get more power out. For a multi-LED arrangement, it would be great to switch each led in at a separate speed. Kinda complicates the electronics, though...

I think my biggest question was: where's the 14W led light?? The schematic showed 4 one watt leds, right?

FWIW, I'm using a 5W Luxeon with my Schmidt dynamo. Works darned nice! Some paralleled leds are added in series for the taillight, and it pretty much meets all of my needs.

okay.. that's enough out of me! Back to the TriLux talk.....

Steve K.

Ktronik 14w Dyno post page

Yes the curves, are tight, but you can change them to be wider + you are using 2 different curves, one in the voltage dob & one in the full wave ref, slow speed no problem gives good light @ 5km/hr!!

Trust me, its the least work needed for a manual switching unit, I also have PCBs now for the Auto switcher between curves..

YOU MUST try these very simple circuits just to prove that yours are better...or not... I have change the circuit a little (different cap config & a bigger standby cap...

Ok using the voltage dob/ full wave ref circuit.. into 4/ series 3w stars I get:

Volt db:
10km/hr, 250ma
15km/hr, 300ma
30km/hr, 250ma

3/ 3w in series gives more power @ lower speeds...

Full wave:

30km/hr, 500ma
40km/hr, 900ma
44km/hr, 800ma

so power @ low speed is ok for me...used a flater curve for the voltage db circuit, more down the bottom end & less drop to transition...
Then a more peaky curve for the full wave so I could hit the max... not too worried about the other side of that curve as not much riding is above 50km/hr...


Sorry Sawtooth no more post here...

 

[greenLED]

:thanks: for the link, Banshee!

 

[Icarus]

Great pics guys! :twothumbs

I have one in the works too (very short cut downs Mag2C) but I'm strugling with mounting it on the handle bar. Any suggestions?

 

[ktronik]

Great pics guys! :twothumbs

I have one in the works too (very short cut downs Mag2C) but I'm strugling with mounting it on the handle bar. Any suggestions?

For My Sub C cutdown bike M@g I used a reflector clamp mounted to the tail cap

very strong very small... works great...

As I run a bike shop I have 100's!!!!!! how many do you want???

I can take pic's if you need...

Thanks

Ktronik

 

[Steve K]

hi Ktronik,

Thanks for the link to the 14W light page. How did I miss it the first time?? d'oh!

Conceptually, I like the idea of the voltage doubler and the cap to improve the impedance matching. In terms of reliability, I'm not so fond of electrolytic caps, especially when I'll be using them at temperatures between 0F and 100F.

Personally, I've been intrigued by the idea of controlling the duty cycle of a buck regulator so as to present a matched resistance to the dyanamo. Unfortunately(?), I've been happy enough with my existing set-up that I just haven't put any effort into it. Seems like I'm having enough trouble finding time to work on projects.... but I did finally finish a 3W Lux conversion of an old Vista VL400 light, using a simple linear current regulator.

thanks,
Steve K.

 

[Icarus]

For My Sub C cutdown bike M@g I used a reflector clamp mounted to the tail cap

very strong very small... works great...

As I run a bike shop I have 100's!!!!!! how many do you want???

I can take pic's if you need...

Thanks

Ktronik

Posting a picture would be great. :thumbsup:

 

[ktronik]

Same clamps as in this post...

 

[Icarus]

Thanks for the link :thumbsup: but I don't think the black plastic snap-arounds are suited for the MagSC. :shrug:

 

[ktronik]

I use them for my SC m@gs, with never a problem... but I take your point...they don't look real nice...

 

[LITEmania]

ktronik :

can you supply me above mount (clamp) to me ?

I'd like to resell here in Korea if you agree...

-warren

 

[ktronik]

ktronik :

can you supply me above mount (clamp) to me ?

I'd like to resell here in Korea if you agree...

-warren

Hey,

The light clamp in the pic is a 'Niterider Universal Mount'

Not from me...

 

[LITEmania]

Thanks for input.
-warren

 

[Sawtooth]

Li-Ion battery pack + waterproof connector cable finally arrived from batteryspace. I am pretty happy with both -- which is a relief as Ive read some negative things about batteryspace on CPF. The battery pack is 14.8V 2.4Ah. It uses 4x18650 LG Li-Ion cylindrical cells. The cells are protected (PTC I think?) and the pack has an additional protection board (over/under voltage protection + over current protection. Cost was $45 ). Seems pretty high quality to me, but I'm no expert... I may add another of these packs in parallel for a 4.8Ah pack...

The waterproof connector cable is also very high quality, but is somewhat more heavy-duty than I actually need. Rated for 8A I think??. I only use 1+-ish amps on the TriLux light though so its a bit overkill....)

I put the battery pack in a water bottle. The pack is wrapped in some air-bubble material that I bought to insulate our ducts in the crawlspace of our house. Its just like the bubble packing stuff for shipping, but is a bit sturdier and is silverized. I'm hoping it'll provide some shock resistance as well as insulation against both daytime heat and winter cold (???).


Ill post some pics soon...

 

[Lumbee1]

BUMP

Any updates to this build? Beamshots?