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

[ktronik]

Hey,

Built up my surly 29er KM as a all rounder, added a basic 3 cree/r2 dyno light with the circuit 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...



enjoy

Ktronik

[climberkid]

thanks for that!! that will help in a build for me.

[n4zou]

Add a USB port for your GPS unit, cell phone, or any other device that can be recharged by plugging it into a USB port.



batteries must be solder tab type with no possibility of an open or poor connection which would allow unfiltered and unregulated power into the USB device possibility damaging it.

[ktronik]

HI, update on the new circuit I am using for my K-light dynamo prototype...

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




K

[JimmyM]

What's the purpose of the capcitor in series with the dynamo?
All 4 of your pictures above are electrically the same. What "Doubler" are you talking about?
The Dynamo is just an AC voltage source, correct?

[ktronik]

What's the purpose of the capcitor in series with the dynamo?
All 4 of your pictures above are electrically the same. What "Doubler" are you talking about?
The Dynamo is just an AC voltage source, correct?

Please see:

http://pilom.com/BicycleElectronics/DynamoCircuits.htm

your questions should be answered there...

Yes it starts as a AC source, a series wired tuning capacitor increases the power at moderate speed, the size of that cap controls where the peak sits...

Some people use a Greinacher voltage doubler in the system, my point I get better use of power when I use 2 different fullwave curves.

I am no engineer, I just build stuff, I have been using these circuit for 5 or so years & its a great simple way to using the power from hub dynamo...

I guess we dynamo dudes are just waiting for someone like you to make a smaller 'pic' based driver, as the caps are big & bulky...

K

[TexLite]

I've seen the schematic drawn as #2 referred to before as a "bridge doubler", with one exception. Instead of one cap it uses two, C1 between Vin and and Vout+ and C2 between Vin and Vout-.

The output is 2*Vin.

Never used one like this, and generally have no idea what I'm talking about[IMG]file:///C:/DOCUME%7E1/Owner/LOCALS%7E1/Temp/moz-screenshot.png[/IMG] , just recall seeing them.

-Michael

[syc]

Cool - you had mentioned the possibility of switching in caps in an earlier post, and I wondered if it had actually been done.

What are you using to switch in the caps? Just a SPST switch that disconnects one of the leads coming from the 2nd pair of caps?

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.

[Calina]

Instead of a description, you could just draw your circuit. It would make things clear for everybody.

What dynamo do you have? I'm sure you mentioned it in another thread but I forgot.

[ktronik]

Instead of a description, you could just draw your circuit. It would make things clear for everybody.

What dynamo do you have? I'm sure you mentioned it in anather thread but I forgot.

Ok Then...





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


hope this helps...

K

PS: I ride the shimano dynamo hubs...cheap & works...

[znomit]

Heres what I'm getting from two leds





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 I'll end up using.

[ktronik]

Fantastic work!!! you spend your time for the good of all!!

looking @ the Lm/speed graph, for 2 LED in series, a total value of 47 & 100uf would make a great dual switcher!!

I would also like to see the curve for total value 220uf....(2S LED)

well done!

Best

Ktronik

[Calina]

Thank you.

[znomit]

I would also like to see the curve for total value 220uf....(2S LED)

Charts updated.

I think I'll do a curve without the boost caps for comparison next weekend too.

I gotta say the caps for the 100uF curve are nice and small and together with a 10V 2200uF smoothing cap make for a compact housing.

[unterhausen]

I need you to re-do this for 3 leds

[znomit]

I need you to re-do this for 3 leds

Have dismantled my test rig and started wiring things up for my new build.

The peaks are at the same speed regardless of number of leds.
Use K's data from the earlier post and shift it to the new peak. Should be close.

[dogxcd]

wld you consider a limited run manufacturing venture ,to sell for those inexperienced in electronic construction?

cheers

d