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My Bicycle

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Not so much...

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I have a new Shamino 6 volt in hub generator. I believe I need a capacitor to steady out the pulsing DC voltage, and hold a minute of charge for when I stop at intersections.

I am using 3 lights: a. 3 watt LED (steady headlight) b. 1/2 watt (blinking front light) c. 1 watt LED (blinking taillight).

Does anyone have any ideas? I am just slightly out of my league on this one and could use some help.
 

tcmtech

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I would be more tempted to just replace the little generator witha set of batteries.

Or at least set it up with a pair of diodes so that when the generator output voltage is higher than the battery voltage the lights run off of it. however when you stop the batteries take over. The diodes will keep each power source from feeding back to each other.

Simple, reliable and easy to build.

:rolleyes:
Or Just get a motorcycle! Its way less effort to run and the lights are way better!
:rolleyes:
 

smanches

New Member
Having almost 5w in lights is going to be hard to power just from a cap at 6v, even for a short period of time. I like the battery/diode idea.

Although a 100uF cap across the generator would help with the voltage ripple.
 

crutschow

Well-Known Member
Most Helpful Member
You could use a 6V rechargeable battery with just one diode from the generator to prevent reverse current through the generator. That way it'll recharge the battery when your are moving.
 

tcmtech

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Most Helpful Member
:rolleyes:

Crutschow! You cant just bring up basic common sense battery charging advice like this! :eek:
The super ultra multistage microprocessor monitored battery charger guys are going to be all over this thread like wolves on a wounded rabbit now! :p

When they get done the OP will have to run a side car on his bike just to carry the tech gear to charge those 5 Ni Cad batteries. Plus he will have to sell his schwinn just to pay for the gear to build his super ultra multistage microprocessor monitored battery charger in the first place. :(

:rolleyes:
 

audioguru

Well-Known Member
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Does the generator regulate its output voltage so it isn't 2V when you go slow and 12V or more when you go fast?
 

Not so much...

New Member
Thanks for all the responses...

I appreciate all the quick and insightful responses.

I would be more tempted to just replace the little generator witha set of batteries.

Or at least set it up with a pair of diodes so that when the generator output voltage is higher than the battery voltage the lights run off of it. however when you stop the batteries take over. The diodes will keep each power source from feeding back to each other.

Simple, reliable and easy to build.


Or Just get a motorcycle! Its way less effort to run and the lights are way better!
__________________
May Rube Goldburg Smile down upon you in all of your misguided efforts.
Batteries are a great idea, I am trying to prove something to myself and I really want to cut my dependence on the outside world as much as possible. Got rid of my car 8 months ago and I only miss it when it rains (really hard rain, light rain is actually more fun).

Got two 5.1V diodes to keep the power going the right way. Will run them in line before a 4800uF capacitor to clean up the fluctuating power coming from the generator and hold the lights on for a bit after I stop moving. (Lights designed for this generator have caps built in to the light so for these purposes, found this out through a little more research.)

I am trying really hard to keep myself from straying too far from home right now and a motorcycle would really get me too far off track. I would love one, but not right now. Maybe in a few years when I can get an electric one!

Having almost 5w in lights is going to be hard to power just from a cap at 6v, even for a short period of time. I like the battery/diode idea.

Although a 100uF cap across the generator would help with the voltage ripple.
I agree, I have chosen to just run my blinking lights with the generator. This will serve 3 purposes. I will be able to use the tactical light as a headlight, as my rifle light, and as my hand light. Saving me 100.00 bucks on extra lights.

You could use a 6V rechargeable battery with just one diode from the generator to prevent reverse current through the generator. That way it'll recharge the battery when your are moving.
Thought about the battery, looked at all my options and decided to hold off on getting that until after I see how the system works without it. Good idea though and I see that happening after my next 100 mile ride.

Crutschow! You cant just bring up basic common sense battery charging advice like this!
The super ultra multistage microprocessor monitored battery charger guys are going to be all over this thread like wolves on a wounded rabbit now!

When they get done the OP will have to run a side car on his bike just to carry the tech gear to charge those 5 Ni Cad batteries. Plus he will have to sell his schwinn just to pay for the gear to build his super ultra multistage microprocessor monitored battery charger in the first place.

__________________
May Rube Goldburg Smile down upon you in all of your misguided efforts.

Just my thoughts.
I already have the bicycle equivalent of a sidecar, Kona UTE, look it up. I am trying to keep everything simple and I am glad someone else believes in simplicity!

The in hub generators seem to be the thing. How do you like it other then flicker?
I am excited to see how it will work. I am going to try to put it together tomorrow, I will let you know. If I can I will set up a picture link. I can tell you that when it isn't working the drag from the generator isn't enough to slow down the wheel in any way I can tell. (and I am a picky *******!)

Does the generator regulate its output voltage so it isn't 2V when you go slow and 12V or more when you go fast?
I have not noticed a great variance in power output, but it does change the # of times per minute the charge is sent out.
 

Not so much...

New Member
Any other suggestions are greatly appreciated. I really want the input and acknowledge my lack of experience as a need for correction.
 

mneary

New Member
If you're contemplating a capacitor such as 4800 uF, consider that a 200 mAH NiMH 6V battery (4 or 5 cells depending on your actual voltage) might be about the same size and do a much better job.
 

Thunderchild

New Member
get a 6 V lead acid battery, much more durable than the Ni cad batteries with more capacity and you will be charging it during the day so have extra power when its dark and you'd have no more problems at all.
 

stevez

Active Member
If faced with this problem I'd take a look at adding a small solar cell if there's enough time when the bike is exposed to light.
 

audioguru

Well-Known Member
Most Helpful Member
The 5W in lights are not a dim low current solar garden light.
The battery will not be charging in the sun all day.
Therefore a solar panel to charge the battery must be huge and very expensive.

Let the generator charge the battery and power the LEDs when the bike is moving.
Let the battery power the LEDs at night if the battery is big enough.
 

stevez

Active Member
Only had a moment to comment on the solar panel before so I'll try it again -

If faced with this problem I'd pull together an energy balance then test to see if a very small solar panel could provide any worthwhile contribution. I do agree that the low power solar lights do demonstrate an order of magnitude sense of things - but if the period that the bike lights are on is relatively short then the contribution of the solar cell might be advantageous. I do know from experience that the load imposed by a generator on the bike isn't large but it is noticeable. If I were to want to sprint a short distance I might want to do so without the extra burden of a generator.
 
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