Voltage Regulated [5v] Bicycle Dynamo Light & USB Charger

Even though, there are plenty of "Dynamo Bike Light" instructions on this site, I thought I would share mines.   The great news, there are NO resistors in my circuit.    It has a fixed 5 volt output, so you can ride as fast as you want without worrying about burning out the LEDs.  Also, since this has a 5v output, you can hook up virtually any high-powered (CREE/Luxeon) LED flashlights (typically rated 4.5v - 8v).  I use this circuit to power a CREE RC-G4 Flashlight , which i bought  from DealExtreme for $17. (It's very bright, but I will most likely upgrade to SSC P7  900-Lumen LED Flash Light, not bad deal for $38.67).

I will also hook up a USB connector plug to charge my BlackBerry Phone and Ipod.  Most USB devices are rated 5v , so with this circuit like this, you will never need to deal with a solar charger to charge your phone, GPS, ipod, recharable batteries, or to power any standard USB device.  

Please refer to Step 1, Step  2, Step 3 & Step 4 for further details..

FYI: This is a work in progress, and I will update my instructions as my project progresses.  Please bear with me given my hectic schedule and feel free to contact me if you have questions regarding where to get the parts or accessories.   And don't forget to leave feedback and suggestions.   

Thank you for visiting & Have a Happy and Safe riding!

Sonnet

Step 1: Building the AC to DC Driver & Voltage regulator circuit..

 
Before you begin, it would greatly help if you review the following links:

      1. Useful Dynamo/LED Circuits:  http://www.pilom.com/BicycleElectronics/DynamoCircuits.htm
      2. Voltage Regulator Circuit:  http://www.youtube.com/watch?v=GSzVs7_aW-Y

 Few Helpful links for novices:   
      1.  Alternating Current (AC)
      2.  Direct Current (DC)
      3.  Full Bridge AC to DC rectification
      4.  Voltage Regulator
      6.  AC generator (Brushless Dynamo)
      7.  DC Motor (Commutated DC motor can also be used to as a DC generator)
      8.  Light Emitting Diodes
      9.  Soldering instructional video


And now...the Nut's & Bolts (Components Required) :

The circuit modules I used have been out there for a while, but what I did is combine both the Full Bridge Circuit & USB Voltage Regulator circuit to make something useful out of it using a bicycle AC generator.

1. [Full Bridge Circuit Diodes]
D1: 1N4007
D2: 1N4007
D3: 1N4007
D4: 1N4007

2. Voltage Regulator Components
[Capacitors: Left to Right]
C1: 10uF
C2: 10uF
C3:   N/A

3. Voltage Regulator [7805 Transistor]
Q1:  7805

4. High Charge Capacitor
Note: I don't have it in shown the circuit diagram.  I will have to try out some high capacitance capacitors to supply voltage to the LEDs when my bike comes at complete halt.   It may take few trials to find a powerful capacitor  that fits the Altoids box, and also holds ample amount charge to keep the LEDs lit for few minutes.  I will update the instructions once i find the best match.  Meanwhile, If you have any recommendations, please feel free to suggest. 

5.  Dynamo Generator:
For this project,  I assumed you already have a dynamo generator for your bike, but no worries if you don't.   I can help get you started.

Bottle Dynamo: If you want to play and get started with one without spending a fortune,  the X Factor 3-Inch Bicycle Generator Light Set  from Amazon would be a great place to start.  They sell for $13.11 at Amazon.  A great & cheap little unit.  This is the one shown in my project.

Hub Dynamo: if you are a more serious rider, you should probably switch to a Hub Dynamo.   You can gather much more information on Hub Dynamo's and lighting on Peter White's website:   http://www.peterwhitecycles.com/shimano3n70.asp

I also highly recommend Anthony from Longleaf Bicycles. A very helpful fellow and awesome wheel builder. You can find great deals here: http://www.longleafbicycles.com

In my opinion, switching to dynamos may seem expensive to start off with, but in the long run, these units pay off and puts back money in your pocket. And, if you are like me, who enjoys cool evening rides during hot summer months, that can save you a lot of dough.

I personally prefer and use both the Bottle and Hub dynamos.  The Advantage of a Bottle dynamo is that you can engage or disengage it as needed, but with Hub Dynamos, you are stuck with it.  It doesn't matter whether or not you need the electricity or not!  This dynamo generators do add some resistance to the wheels, but not noticeable when riding.

Comments

[www.microbike.ie]

Nexus dynamos add resistance only when you are using the light or drain power as far as I know but maybe you have short circuit somewhere

[devDee]

I am working on a similar idea , the only difference is I have very low speed of cycling, around 15 rpm. So please suggest an appropriate dynamo and what changes do i need to make in the circuit to get a constant output of 5V at low speeds. please help!!

[bogyman57]

Good stuff Maynard!

I'm "eagle-ing" it as we speak...

Some questions though:

Just where in the circuit (schematic) does the "big-ass-capacitor" fit?
and,
Have you looked into Supercapacitors yet?
I've had an interest in them, but haven't found much in this niche...

Thanks!

[kebabacool]

Another question/idea; wouldn't it be possible to put a little stack of rechargeable batteries (4x1.5V) between the rectifier bridge and the regulator in order to store some energy and feeding the regulator when not cycling ?? Therefore having some power feeding the lights when not moving.

[kebabacool]

Wouldn't it be possible to use the whole bridge rectifier made of power LED as a taillight ?? Pilom suggest using one of the LED from the bridge as a taillight but why not the four of them ??

Cheeeeers !!

[jmynhier]

thanks for the instructions, I have one question though. why not drill two holes in the side of the flashlight body for the wires to exit and integrate the rear on/off/mode switch of the flashlight into the wiring?

Also check out the new crop of "on/off" hub dynos. In the off position the magnets are disengaged and there is no drag, much like a bottle dyno. I have provided links to three of them below.

thanks,
john

http://www.supernova-lights.com/en/products/infinity_8.html

http://www.bikemania.biz/IRD_Zero_Drag_Front_Generator_Hub_p/merry_30490-30498.htm

http://store.velo-orange.com/index.php/components/wheelsets-rims-hubs/hubs/vo-switchable-dynamo-hub.html

[Malhecho]

good job i wouldnt put this on my lowrider but i wanted something for my mountain bike.

[cpotoso]

A very nice idea. I recommend you take a look at switched regulators (dealsextreme have quite a few, and they are not expensive at all). They do not loose energy to heat like a regular linear regulator (like the one you built). Sometimes they are called buck-boost (or something like that). Check them out!

[sgomes3]

Thank you. A great suggestion indeed. I will do a search on DX to inquire more about it. If you have a direct link or the part number, it would greatly help.

Cheers.

[zazenergy]

This looks really awesome. As a regular cyclist I know I could use something like this. I do think your Instructable could benefit from some more detail. I'm happy to help if you have any questions!

[sgomes3]

Thank you. Yes. I am not 100% done yet. I got a bit too excited and published it soon. This circuit could benefit any touring or commuting cyclist, especially when winter is around the corner and it will be dark outside :)

I will break it down to more steps with more explanation. I am not an expert on electronics by any means, but this circuit seems to work well (took me less than an hour to build). so far, I have not burned any LEDs yet (I rode 2 hrs non-stop). I have yet to stress test it, and hook up a USB device to charge. I will update the instructions as time progresses. Hopefully, it will hold up to my expectations.

Regards,