# 3 Cree/R2 dyno light + circuit re-drawn for newbies



## ktronik (Dec 23, 2006)

Hey,

Built up my surly 29er KM as a all rounder, added a basic 3 cree/r2 dyno light with the circuit (100uf cap) in the fork.



















Also to let people see how easy the martin basic circuit really is, I have re-drawn it, with a pic of what the parts look like the way I build it (dead bug style)...each step is the same circuit, just re-drawn so its easier on the brain...










err looking @ the photo, I guess I need to put it on the other side...better cable routing. DOH

enjoy

Ktronik


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## troutie-mtb (Sep 20, 2007)

Ktronik is the dyno hub ok to use for offroad extreme muddy UK riding 

and what speed does it start to light the lights 

and I suppose with fat tyres you would not even notice any extra drag ?

aslo what make and approx cost? 

ta


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## ktronik (Dec 23, 2006)

First I must say your new light is fantastic!!! very well done...& love the stem mount.. :thumbsup: 

the hub is of 'XT' standard, so will handle anything you can throw @ it...

You can set it up for any type of riding / speed by changing the bi-polar cap, for off-road add a bigger cap (200uf best IMO) or add a voltage doubler, its all simple stuff & works great for 24hr racing... hey I can't afford the cost of batterys for a 24hr race so I use my dynamo...

you can use 1 bi-polar cap (simplest or 4 reg caps if you can't find one)

below is specs for the same circuit just using 4 caps instead of 1 & using a voltage doubler for slow speed, but really the voltage double is not needed, you could just use a 200uf cap (with out Volt Dob) & have very little variation over the whole ride. (See the top specs) 

Fullwave, 4x220uF, 3 LEDs

Read as Speed V I P
4.0 km/h 7.59 V 2 mA 0.01 W
5.0 km/h 8.12 V 23 mA 0.19 W
7.0 km/h 8.71 V 100 mA 0.87 W
9.0 km/h 9.18 V 180 mA 1.65 W
12.0 km/h 9.63 V 310 mA 2.99 W
15.0 km/h 10.05 V 480 mA 4.82 W
18.0 km/h 10.30 V 660 mA 6.80 W
19.0 km/h 10.36 V 670 mA 6.94 W
20.0 km/h 10.28 V 660 mA 6.78 W
24.0 km/h 10.16 V 600 mA 6.10 W
29.0 km/h 10.09 V 570 mA 5.75 W
35.0 km/h 10.04 V 550 mA 5.52 W
53.0 km/h 10.04 V 530 mA 5.32 W

Doubler, 2x220uF, 3 LEDs
Speed V I P
4.0 km/h 8.30 V 41 mA 0.34 W
5.0 km/h 8.58 V 70 mA 0.60 W
7.0 km/h 8.92 V 120 mA 1.07 W
9.0 km/h 9.30 V 200 mA 1.86 W
12.0 km/h 9.76 V 350 mA 3.42 W
13.0 km/h 9.82 V 390 mA 3.83 W
14.0 km/h 9.74 V 370 mA 3.60 W
16.0 km/h 9.60 V 320 mA 3.07 W
18.0 km/h 9.55 V 300 mA 2.87 W
20.0 km/h 9.51 V 290 mA 2.76 W
23.0 km/h 9.48 V 280 mA 2.65 W
26.0 km/h 9.45 V 280 mA 2.65 W
31.0 km/h 9.43 V 270 mA 2.55 W
54.0 km/h 9.40 V 260 mA 2.44 W



Or for ON-road I use 4 100uf caps...CAT. NO. RE6346


Fullwave, 4x100uF, 3 LEDs
Speed V I P
4.0 km/h 7.69 V 3 mA 0.03 W
5.0 km/h 8.14 V 26 mA 0.21 W
7.0 km/h 8.47 V 50 mA 0.42 W
9.0 km/h 8.79 V 100 mA 0.88 W
12.0 km/h 9.16 V 170 mA 1.56 W
15.0 km/h 9.44 V 250 mA 2.36 W
18.0 km/h 9.75 V 350 mA 3.41 W
21.0 km/h 10.04 V 490 mA 4.92 W
23.0 km/h 10.24 V 610 mA 6.25 W
25.0 km/h 10.42 V 740 mA 7.71 W
26.0 km/h 10.50 V 820 mA 8.61 W
27.0 km/h 10.58 V 900 mA 9.52 W
27.5 km/h 10.62 V 910 mA 9.66 W
28.0 km/h 10.55 V 900 mA 9.50 W
30.0 km/h 10.34 V 740 mA 7.65 W
31.0 km/h 10.33 V 710 mA 7.33 W
37.0 km/h 10.14 V 630 mA 6.39 W
43.0 km/h 10.06 V 600 mA 6.04 W
54.0 km/h 10.00 V 570 mA 5.70 W


Doubler, 2x100uF, 3 LEDs
Speed V I P
4.0 km/h 8.10 V 24 mA 0.19 W
5.0 km/h 8.30 V 42 mA 0.35 W
7.0 km/h 8.57 V 70 mA 0.60 W
9.0 km/h 8.79 V 100 mA 0.88 W
12.0 km/h 9.09 V 170 mA 1.55 W
15.0 km/h 9.49 V 270 mA 2.56 W
18.0 km/h 9.89 V 430 mA 4.25 W
19.0 km/h 9.91 V 470 mA 4.66 W
19.5 km/h 9.93 V 490 mA 4.87 W
20.0 km/h 10.00 V 500 mA 5.00 W
20.4 km/h 9.70 V 400 mA 3.88 W
20.5 km/h 9.68 V 390 mA 3.78 W
21.0 km/h 9.64 V 370 mA 3.57 W
21.7 km/h 9.63 V 360 mA 3.47 W
24.0 km/h 9.57 V 330 mA 3.16 W
28.0 km/h 9.49 V 310 mA 2.94 W
36.0 km/h 9.42 V 290 mA 2.73 W
55.0 km/h 9.37 V 270 mA 2.53 W



if you are really really fast or ebike you could use 47uf for MAX power output, but real peaky curve...

Fullwave, 4x47uF, 3 LEDs
Speed V I P
4.0 km/h 7.60 V 2 mA 0.02 W
5.0 km/h 7.83 V 9 mA 0.07 W
7.0 km/h 8.14 V 29 mA 0.24 W
9.0 km/h 8.44 V 61 mA 0.51 W
12.0 km/h 8.75 V 109 mA 0.95 W
15.0 km/h 9.03 V 160 mA 1.44 W
18.0 km/h 9.20 V 210 mA 1.93 W
21.0 km/h 9.42 V 270 mA 2.54 W
24.0 km/h 9.60 V 330 mA 3.17 W
27.0 km/h 9.81 V 420 mA 4.12 W
30.0 km/h 10.04 V 530 mA 5.32 W
33.0 km/h 10.28 V 680 mA 6.99 W
36.0 km/h 10.52 V 860 mA 9.05 W
37.0 km/h 10.53 V 920 mA 9.69 W
39.0 km/h 10.75 V 1050 mA 11.29 W
40.5 km/h 10.85 V 1150 mA 12.48 W
42.0 km/h 10.24 V 750 mA 7.68 W
44.0 km/h 10.26 V 720 mA 7.39 W
53.0 km/h 10.16 V 640 mA 6.50 W



Doubler, 2x47uF, 3 LEDs
Speed V I P
4.0 km/h 7.91 V 13 mA 0.10 W
5.0 km/h 8.05 V 21 mA 0.17 W
7.0 km/h 8.29 V 42 mA 0.35 W
9.0 km/h 8.47 V 63 mA 0.53 W
12.0 km/h 8.73 V 102 mA 0.89 W
15.0 km/h 8.96 V 140 mA 1.25 W
18.0 km/h 9.19 V 200 mA 1.84 W
21.0 km/h 9.46 V 280 mA 2.65 W
24.0 km/h 9.71 V 380 mA 3.69 W
27.0 km/h 10.00 V 510 mA 5.10 W
29.5 km/h 10.16 V 610 mA 6.20 W
30.0 km/h 9.70 V 380 mA 3.69 W
31.0 km/h 9.65 V 370 mA 3.57 W
32.0 km/h 9.62 V 360 mA 3.46 W
35.0 km/h 9.55 V 330 mA 3.15 W
54.0 km/h 9.40 V 290 mA 2.73 W


I can't feel the drag, & still go great in racing, passing heaps of people, but I am on a 29er so its a little un-fair for the smaller wheeled guys...

hope that helps...

Ktronik


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## znomit (Dec 27, 2007)

troutie-mtb said:


> ...and what speed does it start to light the lights
> and I suppose with fat tyres you would not even notice any extra drag ?
> aslo what make and approx cost?


Troutie I use a doubler circuit at low speed and get enough light from walking pace. Its nice how the brightness ramps up smoothly as speed increases. Magic. :thumbsup:

I can just notice the drag if I turn the lights on/off but it doesn't feel like anything is slowing you down otherwise. 
I just got a MTB hub for around 50 of your pounds.... labour, spokes and a new disc doubled the cost. Cheaper than batteries long term and just jump on and ride.
Oh yeah, dynamos are constant current devices so ideal for driving an MC-E or two. :winker: :winker:

Kerry have you tried the new cree optics from cutter?


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## ktronik (Dec 23, 2006)

No not yet, 10 deg is narrow enough for me... & you can't beat the price... you??

K


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## ktronik (Dec 23, 2006)

znomit said:


> Oh yeah, dynamos are constant current devices so ideal for driving an MC-E or two. :winker: :winker:


I can't wait, these are ideal for dynamo lights as you can run them in series!

Znomit, you could have just one 4 die LED, for a dyno light for your road bike how lite & small would that be!!!


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## znomit (Dec 27, 2007)

ktronik said:


> I can't wait, these are ideal for dynamo lights as you can run them in series!
> 
> Znomit, you could have just one 4 die LED, for a dyno light for your road bike how lite & small would that be!!!


I know.... and you can run different dies in series/parallel to customise output beam profile. Should rock on the dyno, might even sort out my brake caliper mounting, should work with just one led.
Think I'll wait till summer to start playing, my triple is great and the MC-E wont have R2 efficacy for a while.


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## ktronik (Dec 23, 2006)

Ok ,you will wait till its gets to R2 eff... but by then what will single die LEDs be @??? & when will the gap between the two be bridged??... I know you... you will wait 2 mins after they are avab & stable...  

K


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## znomit (Dec 27, 2007)

ktronik said:


> Ok ,you will wait till its gets to R2 eff... but by then what will single die LEDs be @??? & when will the gap between the two be bridged??... I know you... you will wait 2 mins after they are avab & stable...
> 
> K


I expect R4 will arrive before the end of the year. I dunno if things will get brighter like they did last year, was cool with my builds going from P3 to R2 in such a short time ...

Yeah I'd like to do a few things and have a few ideas but with a new baby and having to train for 4x taupo not much time for light building... hence the nightlightning MTB head. Like to do a stealthy single MC-E brake caliper mounted but will need some nice machining done.... :ihih: :ihih: :ihih: :ihih: :ihih: :ihih: :ihih: :ihih: :ihih:


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## troutie-mtb (Sep 20, 2007)

You lot talk in a strange language I have never been able to get my head round 
electronics and the maths
so I will leave it up to the experts and stick to the engineering side 

I wish you had not posted this thread cos it just puts another thing on my wishlist

I really do like the idea of the dyno hub and no battery it goes well well with the minimalist stem faceplate light and new MC E 


I expect to see a very neat cnc `d stem light soon from Ktronik 

the problem is that stems are all different so there is no mass market for this idea 


I will be back for electronic advise when I have saved up some spare cash for a dyno hub
and wheel build

cheers Chris


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## ktronik (Dec 23, 2006)

troutie-mtb said:


> You lot talk in a strange language I have never been able to get my head round
> electronics and the maths
> so I will leave it up to the experts and stick to the engineering side
> 
> ...


I think your stem mount is an engineering marvel, as how you gunna cool a light that small & that powerfull... I see no other way...I was toying with the idea after Dom made his minty as the small size was hard to keep cool when not moving & on high beam, but in the end dismissed it due to the facts you have just stated (not all stems are the same)

My idea is to be direct bar mount as only 2 sizes to deal with (26.4mm & 31.8mm)

dynolights don't this problem as much, as the faster you go, the more power / light you have, the more cooling you get... a match made in heaven... in fact when you ride dynamo its very hard to go back to batts...& the fact that we can get so much power from them & LEDs give so much light for that power is just fantastic...

when I first told martin how much power I was getting from the hub, using his circuit, he did not believe me, so he rang me up from Germany & quizzed me to see if I was right...

glad he did as look how far we have come...& now the MC-E is coming out, I feel a huge shift coming, in the way all bike lights will be built / made...

your new light could very easily just have a built in bar clamp on either side of the stem, & thus be more campatable with my bike... err other peoples bike... :yesnod: :thumbsup:

Please don't be teched out buy the science of it all, as with a team like Zno, Martin & I, you will always have the help you need, & after the first time you make one, you will slap yourself for thinking it was hard...

K


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## troutie-mtb (Sep 20, 2007)

ktronik said:


> I think your stem mount is an engineering marvel, as how you gunna cool a light that small & that powerfull... I see no other way...I was toying with the idea after Dom made his minty as the small size was hard to keep cool when not moving & on high beam, but in the end dismissed it due to the facts you have just stated (not all stems are the same)
> 
> My idea is to be direct bar mount as only 2 sizes to deal with (26.4mm & 31.8mm)
> 
> ...


What do you do when you stop at a red light and the light goes out do you have a backup be seen light too.

Yes the barclamp works well to transfer the heat as my other lights proved but everyone has lights bar mounted , this just has a minimalist fit and forget approach and everyone needs a challenge now and again :madman:

and will defo be back for help in the future , only problem is the wife has vetoed me spending on hobby stuff for a while.:nono: :nono:

This forum must inspire so many folk to have a go at a do it youself light


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## ktronik (Dec 23, 2006)

for when I stopped I was using my dyno-batt, but to save room I just use a good flashey...

Err Defo??... mate you better get in there & do the dishes right now, oh & make the bed...happy wife = more lights... 

K


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## troutie-mtb (Sep 20, 2007)

defo a bit of UK slang for definatly

Just had a look at this 
http://www.kinetics.org.uk/html/son_hub_dynamo.shtml

quite a bit pricy :eekster: , that is a lot of dishwashing


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## ktronik (Dec 23, 2006)

troutie-mtb said:


> defo a bit of UK slang for definatly
> 
> Just had a look at this
> http://www.kinetics.org.uk/html/son_hub_dynamo.shtml
> ...


 I see, no worries cobber...mate if you can buy a SON do it...these are the best you can get IMO... just lock your front cones a bit tighter so your hub looks like its flogged out... _'honey, my F hub died & I will have to use you car to get to work...'_... you will have your SON pretty quick... :thumbsup:

K


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## znomit (Dec 27, 2007)

troutie-mtb said:


> What do you do when you stop at a red light and the light goes out do you have a backup be seen light too.


I tried glow in the dark powder, have very cool looking lights now but not quite bright enough. 
I figure you always need a backup anyway so I run a blinky too. Can't fix a puncture with just a dyno light. :nonod:


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## ktronik (Dec 23, 2006)

but can you fix a flat with a blinky??

I learnt the hard way...when I built my first dyno light (maglite head with 3 Lux3s) I went for a test in the bush... had a wash out & a step off on a bend...well I can tell ya its very dark in the bush @ night... luckily my rear flasher was going so I could find my bike...

always use a back up light or better a head mounted light to see around the bend...:thumbsup: 

K


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## iq2k (Jul 5, 2008)

troutie-mtb said:


> defo a bit of UK slang for definatly
> 
> Just had a look at this
> http://www.kinetics.org.uk/html/son_hub_dynamo.shtml
> ...


I got a knotchy feeling shimano hub :nono: & an is it even on schmidt:thumbsup: :thumbsup: :thumbsup: there is no compairing them the schmidt is far better. 
shimano you kinda no when the lights are on but with the schmidt who cares LED's wont burn out drag what drag.

the B&M ixon light has 4 X AA batteries in that can be charged as you ride or other nm-mh.
Theres a few things in there favour, they both mean my lights are well fixed so i never have to look for them nor batteries & thieves think there old man of the alotment type stuff & just pass them by.:thumbsup: :thumbsup:


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## dazzat3 (May 4, 2008)

*Dynamo lumen dealer*

Hi All,

Well, I met Ktronik yesterday, top bloke:thumbsup: ... and extremely knowledgeable, with all things electronic, particularly dynamo lights...and more than willing to pass that knowledge on.
Ktronik gave me a demo on the 3 x R2 dyno light which pumped out penty of light with him just walking beside his Surly 29er and only got brighter as his speed increased...well as fast as you can ride around a clothes line (Hills hoist) in the back yard...very impressive...I'm sure most people would hooked on the Dyno light lumens after seeing light output like this.

I'm now convinced the circuit below is the best for my new light.

Fullwave, 4x100uF, 3 LEDs
Speed V I P
4.0 km/h 7.69 V 3 mA 0.03 W
5.0 km/h 8.14 V 26 mA 0.21 W
7.0 km/h 8.47 V 50 mA 0.42 W
9.0 km/h 8.79 V 100 mA 0.88 W
12.0 km/h 9.16 V 170 mA 1.56 W
15.0 km/h 9.44 V 250 mA 2.36 W
18.0 km/h 9.75 V 350 mA 3.41 W
21.0 km/h 10.04 V 490 mA 4.92 W
23.0 km/h 10.24 V 610 mA 6.25 W
25.0 km/h 10.42 V 740 mA 7.71 W
26.0 km/h 10.50 V 820 mA 8.61 W
27.0 km/h 10.58 V 900 mA 9.52 W
27.5 km/h 10.62 V 910 mA 9.66 W
28.0 km/h 10.55 V 900 mA 9.50 W
30.0 km/h 10.34 V 740 mA 7.65 W
31.0 km/h 10.33 V 710 mA 7.33 W
37.0 km/h 10.14 V 630 mA 6.39 W
43.0 km/h 10.06 V 600 mA 6.04 W
54.0 km/h 10.00 V 570 mA 5.70 W

The circuit Ktronik has drawn up, really is very simple...but I must admit that I didn't realise just how simple it was unitl I saw laid out in front of me.

drawing 4 is the one to look at


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## jimgskoop (Apr 13, 2006)

What does the bi-polar cap do?


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## Calina (Apr 8, 2008)

jimgskoop said:


> What does the bi-polar cap do?


Jim, check your thread on CPF for the answer: http://www.candlepowerforums.com/vb/showthread.php?t=233964


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## unterhausen (Sep 28, 2008)

bipolar replaces the two electrolytic caps and resistor in Martin's circuit. Basically, that's what a bipolar cap is.

It's for the voltage doubler


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## jimgskoop (Apr 13, 2006)

unterhausen said:


> bipolar replaces the two electrolytic caps and resistor in Martin's circuit. Basically, that's what a bipolar cap is.
> 
> It's for the voltage doubler


Is a bipolar cap the same thing as a non-polar cap?

http://www.allelectronics.com/make-a-store/category/140900/Capacitors/Non-Polar/1.html

If all you need to do is wire a non-polar cap in series with the dyno hub (before the rectifier) I might try this out. What is the correct rating for a non-polar cap? Martin says "A monstrous 1500uF" -- but it seems that you guys are using 200uF? And what's the voltage rating (100V)?

Thanks!
-Jim G


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## unterhausen (Sep 28, 2008)

I forget exactly what size I used. I was too lazy to figure out what the equivalent value bipolar was for his caps. I think I used a 1500uF bipolar for 3 leds. My light flashes a little at low speeds. I couldn't fit a bigger cap in there with the smoothing cap. 

Your link shows a bipolar cap.


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## CSonmor (Apr 22, 2009)

*A couple of questions re: dyno lights*

I'm very interested in building a similar light for my touring/commuting bike (700c wheels). I already purchased the leds, optics, and a bflex (original plan was to have it battery powered), when I found this thread, and the dyno idea really appeals. I've re-read the thread several times, and followed all the links, and still have a couple of questions:

1. What hub (make/model) are you using, or would you recommend, for moderate-speed road riding?

2. The hubs I've found are all rated at around 6V, 3W (0.5 A), so I don't understand how you can drive 3 leds wired in series, each with a Vf of 3.7V. Unless I'm misunderstanding, the drawings on this thread do NOT have a voltage doubler in them so it should never put out more than 6V, which shouldn't even drive 2 leds.

Thanks,
Chris


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## unterhausen (Sep 28, 2008)

I'm using a Shimano on all my rides now, leds on the whole time. I don't really notice the difference. I do notice the vibration at high speeds. SON is better, but a lot more money. 

Dynohubs are a current source, so the voltage floats up to whatever it takes to drive that current (simplified immensely). There is some limit to how far this effect will take you, and at very slow speeds you get less light with more leds. I'm runing 3 leds on my hub. It works down to a very slow speed, although I do have a very carelessly designed voltage doubler on mine.


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## jimgskoop (Apr 13, 2006)

CSonmor said:


> I'm very interested in building a similar light for my touring/commuting bike (700c wheels). I already purchased the leds, optics, and a bflex (original plan was to have it battery powered), when I found this thread, and the dyno idea really appeals. I've re-read the thread several times, and followed all the links, and still have a couple of questions:
> 
> 1. What hub (make/model) are you using, or would you recommend, for moderate-speed road riding?


SON 28, SON 20R, Shimano DH-3N70 series, Shimano DH-3N80 series.



> 2. The hubs I've found are all rated at around 6V, 3W (0.5 A), so I don't understand how you can drive 3 leds wired in series, each with a Vf of 3.7V. Unless I'm misunderstanding, the drawings on this thread do NOT have a voltage doubler in them so it should never put out more than 6V, which shouldn't even drive 2 leds.


Dynamos are roughly 500mA constant-current AC sources -- but the voltage they produce depends on the load applied. See http://pilom.com/BicycleElectronics/HubDynamo.htm

"To see whats possible, I ran a Shimano DH-3D71 at 136 km/h in a test stand. The voltage generated was sufficient to ignite a fluorescent tube and subsequently drive it at 55 V and 500 mA."

The flip side to this is that if you connect a series string of LEDs to the hub, you won't get any light output at low speeds, since the output voltage at the hub drops as its RPMs slow (more LEDs require higher combined Vf as you mentioned). The work around is to create a voltage-doubler circuit that kicks in at low speed, or to use a manual switch to bypass some of the LEDs (what I've done in my own light).

-Jim G


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## ktronik (Dec 23, 2006)

HI,

I now use 4 /220uf low esr / high ripple reg cap's, instead of a bi-polar cap.

I use 2 to form a 100uf bi-polar, then switch in a second string, so switching 100/200uf in place of bi-polar, most of the time I am in 200uf mode, but nice to switch for more power around 27-35 or for less power drain at low speed when I want less drag...

This give's me better results than the fullwave / voltage doubler config.

if you compare the data below you will see what I mean

EX: on fullwave 200uf @ 15km/hr I get 480ma across the string of 3 LEDs

if I had a 100uf fullwave & switched in the doubler I only get 430ma.

so better use of the power I feel with this config...

Fullwave, 220uF, 3 LEDs

Read as Speed V I P
4.0 km/h 7.59 V 2 mA 0.01 W
5.0 km/h 8.12 V 23 mA 0.19 W
7.0 km/h 8.71 V 100 mA 0.87 W
9.0 km/h 9.18 V 180 mA 1.65 W
12.0 km/h 9.63 V 310 mA 2.99 W
15.0 km/h 10.05 V 480 mA 4.82 W
18.0 km/h 10.30 V 660 mA 6.80 W
19.0 km/h 10.36 V 670 mA 6.94 W
20.0 km/h 10.28 V 660 mA 6.78 W
24.0 km/h 10.16 V 600 mA 6.10 W
29.0 km/h 10.09 V 570 mA 5.75 W
35.0 km/h 10.04 V 550 mA 5.52 W
53.0 km/h 10.04 V 530 mA 5.32 W

Doubler, 220uF, 3 LEDs
Speed V I P
4.0 km/h 8.30 V 41 mA 0.34 W
5.0 km/h 8.58 V 70 mA 0.60 W
7.0 km/h 8.92 V 120 mA 1.07 W
9.0 km/h 9.30 V 200 mA 1.86 W
12.0 km/h 9.76 V 350 mA 3.42 W
13.0 km/h 9.82 V 390 mA 3.83 W
14.0 km/h 9.74 V 370 mA 3.60 W
16.0 km/h 9.60 V 320 mA 3.07 W
18.0 km/h 9.55 V 300 mA 2.87 W
20.0 km/h 9.51 V 290 mA 2.76 W
23.0 km/h 9.48 V 280 mA 2.65 W
26.0 km/h 9.45 V 280 mA 2.65 W
31.0 km/h 9.43 V 270 mA 2.55 W
54.0 km/h 9.40 V 260 mA 2.44 W

Fullwave, 100uF, 3 LEDs
Speed V I P
4.0 km/h 7.69 V 3 mA 0.03 W
5.0 km/h 8.14 V 26 mA 0.21 W
7.0 km/h 8.47 V 50 mA 0.42 W
9.0 km/h 8.79 V 100 mA 0.88 W
12.0 km/h 9.16 V 170 mA 1.56 W
15.0 km/h 9.44 V 250 mA 2.36 W
18.0 km/h 9.75 V 350 mA 3.41 W
21.0 km/h 10.04 V 490 mA 4.92 W
23.0 km/h 10.24 V 610 mA 6.25 W
25.0 km/h 10.42 V 740 mA 7.71 W
26.0 km/h 10.50 V 820 mA 8.61 W
27.0 km/h 10.58 V 900 mA 9.52 W
27.5 km/h 10.62 V 910 mA 9.66 W
28.0 km/h 10.55 V 900 mA 9.50 W
30.0 km/h 10.34 V 740 mA 7.65 W
31.0 km/h 10.33 V 710 mA 7.33 W
37.0 km/h 10.14 V 630 mA 6.39 W
43.0 km/h 10.06 V 600 mA 6.04 W
54.0 km/h 10.00 V 570 mA 5.70 W

Doubler, 100uF, 3 LEDs
Speed V I P
4.0 km/h 8.10 V 24 mA 0.19 W
5.0 km/h 8.30 V 42 mA 0.35 W
7.0 km/h 8.57 V 70 mA 0.60 W
9.0 km/h 8.79 V 100 mA 0.88 W
12.0 km/h 9.09 V 170 mA 1.55 W
15.0 km/h 9.49 V 270 mA 2.56 W
18.0 km/h 9.89 V 430 mA 4.25 W
19.0 km/h 9.91 V 470 mA 4.66 W
19.5 km/h 9.93 V 490 mA 4.87 W
20.0 km/h 10.00 V 500 mA 5.00 W
20.4 km/h 9.70 V 400 mA 3.88 W
20.5 km/h 9.68 V 390 mA 3.78 W
21.0 km/h 9.64 V 370 mA 3.57 W
21.7 km/h 9.63 V 360 mA 3.47 W
24.0 km/h 9.57 V 330 mA 3.16 W
28.0 km/h 9.49 V 310 mA 2.94 W
36.0 km/h 9.42 V 290 mA 2.73 W
55.0 km/h 9.37 V 270 mA 2.53 W


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## znomit (Dec 27, 2007)

Nice K
The 100uf fullwave looks like a good curve to ride with on the road. 
What are the voltage specs on the caps that form the bipolar?

I'm just putting a single mode dual led together, any ideas on cap values for a similar 30kph peak?


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## ktronik (Dec 23, 2006)

znomit said:


> Nice K
> The 100uf fullwave looks like a good curve to ride with on the road.
> What are the voltage specs on the caps that form the bipolar?
> 
> I'm just putting a single mode dual led together, any ideas on cap values for a similar 30kph peak?


I only use to use the 100uf, but now I find the 200uf better for the hillier stuff around where I now live...

Jaycar CAT. NO. RE6336

Capacitor Electrolytic 220uF 35V 105C L/ESR

FEATURES:

1. Stable, low impedance characteristics
2. High ripple current
3. Low D.C. leakage current
4. Extended life - high reliability withstanding 2,000 to 4,000 hours load life at 105°C
5. 105°C
6. Radial leads on standard pitch

* Impedance: max at 20°C 100kHz

** Ripple current measured at 105°C 100kHz

Size (Dia x Lmm): 8x16

Impedance: 0.09

Ripple Current mA rms: 840

Sorry I don't have data of the 2 series with the same curve...

K


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## znomit (Dec 27, 2007)

ktronik said:


> Sorry I don't have data of the 2 series with the same curve...


Dammit :incazzato: Will have to measure stuff for myself! 

I see now this is just matins circuit 7 with a "too small" cap. Correct?

Got an assortment of caps from Jaycar today and will see about wiring some test gear up tonight.


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## ktronik (Dec 23, 2006)

znomit said:


> Dammit :incazzato: Will have to measure stuff for myself!
> 
> I see now this is just matins circuit 7 with a "too small" cap. Correct?
> 
> Got an assortment of caps from Jaycar today and will see about wiring some test gear up tonight.


Basically yes, back in the say before that page was up, back when martin & I first started testing the stuff, we saw that the ripple current rating on the bi-polar cap was a little low for what we were doing...thus the shift to Low ESR, high ripple caps...but I then use a extra string for the switcher...if you look at the data box & am just using the caps it says for 6LEDs & get the same power into 3...

When I build my test rig, I will do more tests...

K


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## znomit (Dec 27, 2007)

Sweet. It all just clicked today, caps wired in inverse series with a bleed resistor to form a bipolar. 

Got mine setup, just need to figure out how to spin the wheel, read the speed, ammeter and voltmeter all at the same time. :crazy: 

Have 47, 100, 220, 470uF caps so should get a few curves over the weekend. :thumbsup:


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## ktronik (Dec 23, 2006)

Make sure you get the blead resistor to the right end of the circuit...so on circuit 7 you see the two '+' ends connected & blead to '+', for a second string 'inverse' the other way & blead to ground...so two '-' connected & blead to ground...(only if using a second string)

For my test rig, what I plan to use: a dual temp meter, GPS, current, voltage...then with the time code on a small digital camera, record the meters going on a test ride...

can be done quite cheaply with little meters like these but one for current (with shunt) & one for volts, but not the temp one...

This one for temp...

Then replay, read off the data, into excel, for graphing...

so I can have a graph for:

speed (very close to wind speed on a still day)
elevation (m)
dual temp (amb & LED)
current (for battery tests)

& voltage / current (for dynamo stuff)

all on the same graph / over time...I will really see what's going in then...to get tricky I could also add a wind speed meter...

much cheaper than 4 or 5 data loggers...

K


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## znomit (Dec 27, 2007)

I'm trying to keep things simple so this will just be a single mode, the caps are small enough that they should fit in a moderate sized housing too. 

I have the meters setup on the bench with time lapse camera to record values and bike upside down, drill with a sanding drum on it spinning the wheel. Should work nicely.


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## ktronik (Dec 23, 2006)

znomit said:


> I'm trying to keep things simple so this will just be a single mode, the caps are small enough that they should fit in a moderate sized housing too.
> 
> I have the meters setup on the bench with time lapse camera to record values and bike upside down, drill with a sanding drum on it spinning the wheel. Should work nicely.


Oh I see, but that way you miss the danger of rocketing down a hill with a meter strapped to your bar, with one eye on that & one on the road!! :thumbsup:

At least you will be alive to post your results, so all good...

K


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## mrbubbles (Apr 9, 2007)

Is there a bi-polar cap for 4 LED similar to 3 LED 200UF fullwave?


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## ktronik (Dec 23, 2006)

mrbubbles said:


> Is there a bi-polar cap for 4 LED similar to 3 LED 200UF fullwave?


you talking overall power or the shape of the curve??

you talking 4 LED in series?? using the same bi-polar cap is fine for 4S LED you get / use the same power overall, but the curve is a little different due to the higher Vf of the 4S string...less peak power down low, but a little more effecent due to the extra LED in the string...so a little more light @ higher speeds but less down low...

4 LED in a 2S2P is different again...znomit is doing 2 LED (2s) testing at the moment & has some great data that he might share if you are nice to him :thumbsup:

K


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## ktronik (Dec 23, 2006)

you can see from the first pic, its a symetrical full/ doubler .

by moving the switch to SW2 position you get full/full wave switcher...

maybe even try both...that way you would have full/ doubler & when in full, the second fullwave mode...have not done this as doubler is not as good if you forget to switch back...each full/full mode is fine to ride in by itself...

hope this helps...

K


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## znomit (Dec 27, 2007)

Ok so heres what I got this weekend.



















Note the peaks aren't so peaky when you look at the lumens as efficiency drops off at higher mA.

Listed cap values are what I used, so 100uF is two 100uF in series, eq to a 50uF bipolar. 
Just a single set of caps, not 4 but I will change that as they were getting quite warm.

Peaked at 1.12A!

The dropoff past the peak is pretty obvious.

The pink is probably what Ill end up using.


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## mrbubbles (Apr 9, 2007)

ktronik said:


> you talking overall power or the shape of the curve??
> 
> you talking 4 LED in series?? using the same bi-polar cap is fine for 4S LED you get / use the same power overall, but the curve is a little different due to the higher Vf of the 4S string...less peak power down low, but a little more effecent due to the extra LED in the string...so a little more light @ higher speeds but less down low...
> 
> ...


I already have 4s wired up, I am looking at bi-polar cap that has similar equivalent output, but that's not really necessary so I'll go with 35v 220uf bi-polar cap you mentioned in post 30. Assuming it is compatible. Gonna keep it simple without switching between full wave and doubler.










Is the +- block in the middle of circuit 4 a capacitor? If it is, what voltage would you recommend?


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## ktronik (Dec 23, 2006)

mrbubbles said:


> I already have 4s wired up, I am looking at bi-polar cap that has similar equivalent output, but that's not really necessary so I'll go with 35v 220uf bi-polar cap you mentioned in post 30. Assuming it is compatible. Gonna keep it simple without switching between full wave and doubler.
> 
> 
> 
> ...


Hi,

Don't think you will find a 220 bi-polar cap, I had to use 2 100uf caps in parallel. (Cap refered to in post #30 is a regular NON bi-polar cap & @ least 2 would be needed to form a bi-polar)

pic 3 & 4 are the same, so the poorly drawn pic (sorry) 4, with the + & - next to it is the 4 diodes that make the bridge recitifer, & the line across them is the 'band' that is on the diode, looking @ them on a black diode the band is white, it is important that you wire the diodes this way...

But I think you mean the smoothing cap next to the LEDs (pic 4)...2200-4700uf is fine with a 25+ voltage. Higher voltage is always better if you can fit it...

you could also make a easy stand light with a parallel string (next to LEDs) of 4 /5.5v 0.047f super caps...(for 4 LEDs) these are quite small so won't take up much room... just wire parallel to the LED string...

good luck

K


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## znomit (Dec 27, 2007)

ktronik said:


> 4 LED in a 2S2P is different again...znomit is doing 2 LED (2s) testing at the moment & has some great data that he might share if you are nice to him :thumbsup:
> 
> K


Right-O

Series wired MC-E

individual cap values, so two 470uF in series.

See Martins circuit 7, actually he recommends 470uF, and my results here are identical to his. Nice to know.
The 220 peaks at 27.5 same as the triple and you get a little over 700mA, about 9W.
Less at lower speeds.
I couldn't get readings at 5kph.

kph on 700c wheels, mA to led

Speed . . . 470uF . . . 220uF
10 ............123 ..........100
15 .............355 .......... 240
20 ............ 525 .......... 410
25 ............ 540 .......... 690
27.5 ......... 530 .......... 730
30 ............ 560 .......... 650
35 .............................590
40 ............................. 550


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## ktronik (Dec 23, 2006)




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