/diy/ - Do It Yourself

>>515179
That will work well for making a bike generator.

You'll need a charge controller and at least a blocking diode. Though, it is better to have a bridge rectifier than a blocking diode. The charge controller is a headache saver.

I've built one of these before. To charge a 12v battery it takes quite a bit of force. If you have a battery array you can increase your RPMs by making the array have a higher voltage. Like 24v or 48v. With the 12v array the amps you crank out will be around 2.5A to 5A max most likely. 2.5A will be a real nice workout. 3A is a hard workout and 5A is just murder and you'll last only a little bit probably.

Here's the charge controller I use:

http://www.mwands.com/index.php?main_page=product_info&cPath=55_35&products_id=464

I'm glad I didn't get a cheaper one, since I can use the one above for several power-generating projects at the same time. Here's a cheaper alternative,

http://www.harborfreight.com/7-amp-solar-charge-regulator-96728.html

I bought my 800v 25amp bridge rectifiers from, and got beefy ones so I could also use those with other projects,

http://www.mouser.com/ProductDetail/Vishay/GBPC2508-E4-51/?qs=%2fha2pyFadugV2i03Pvz7elamO30MzeMuVBRGs7UhZLF4gAUEZINcXA%3d%3d

You can get a blocking diode that can handle 5-10 amps and tons of volts for pretty cheap.

My biggest tip is to make the pulley/chain system adjustable so you can put the pulley/chain on easily, but make it VERY sturdy. When you start cranking out those amps after reaching the charging voltage it can put massive strain on the pulley/chain. Also, monitor the temperature of the motor you are using. Check it after 10 minutes, 30 minutes and 1 hour. Don't let it get too hot. Although, those are beefy motors and can take punishment.

>>515179
byump

>>515185
Where can a belt that large be bought?
Can I just remove the rear tyre from a bike and run the belt around the bike rim? It would simplify this idea a lot to be able to simply take any bike w/no mods needed.

(not op but interested)

>>515185

when i was younger, i always wanted to know why it was impossible to generate power that will power a motor to rotate the generator

nobody invented yet a motor which can rotate strongly without using much power?

>>515654
You can hook a chain to the bikes existing gears if you want to.

Belts that large would be for lawnmowers.

However, for a non-modded bike you simply make a frame to rest the wheel of the bike on and clamp it in place. The wheel would be resting on something that turns the generator. Then you could use any bike. These are already made and sold, so you can see what they look like online.

http://www.triplepundit.com/2011/03/future-pedal-power-remote-places/

>>515746
I'm not sure I understand. Are you referring to making a motor that is super energy efficient? so efficient that it takes less energy for the motor to rotate the generator so the generator can make more power?

If that is correct then you'd need to know that it won't work. If that is incorrect then please reword your statement/question.

>>515791
i meant this
a generator powering a motor which rotate the generator

>>515185
OP has a DC motor. He doesn't need a bridge rectifier.

>>515977

Sorry the current laws of physics and thermodynamics don't allow that to exist.

>>515746

>nobody invented yet a motor which can rotate strongly without using much power?

A motor is a kind of Transducer. A Transducer is a device that turns one type of energy into another. Power is energy per unit time. Electric motors, specifically, are transducers that turn electrical power into power in the form of rotational movement.

The power of a motor, (ie: Horsepower), is going to be equal to or less than the electrical power (watts) used to drive it. A perfectly (100%) efficient one horsepower motor will still require about 745.6 watts of electricity. That's about 6.8 Amps from the wall socket.

>>515990

Anyway, motors these days can be over 90% efficient, which is pretty good. Even a rather basic one is probably pushing 80%.

>>515990
>2013
>still using horsepower
>mixing S.I. units and imperial retard units in the same sentence
>being that American

>>516008
> picking on someones terminology because that's the most intelligent thing you can say.
> he's still right.

>>516012
he may be right, but consistency is important.

>>516016

It's perfectly consistent. The horsepower is now a defined unit equal to 746 watts.

If you want to go full American, there's always kips, tens, mills, or m-foot.

>>516021
>The horsepower is now a defined unit equal to 746 watts

which horsepower?

>>515791
Even if the motor is super efficient, the human body is not so much. You do realize the typical person will generate only about 100w, and at a very poor conversion rate of kcal.

> which horsepower?

the horsepower that's stamped on a plate on pretty much any motor of substance you will find in the Americas.

>>515988
He needs it if he wants to pedal backwards. I do that all the time in order to give my muscles a partial rest and not stop pedaling.

>>516033
We are all talking about electric motors here. Meaning we'd be talking about horsepower in relation to those electric motors. Why would we be talking about other types of horsepower?

Here,

>One horsepower for rating electric motors is equal to 746 watts.

http://en.wikipedia.org/wiki/Horsepower#Definitions_of_term

>>516038
I don't see a problem.

>You do realize the typical person will generate only about 100w, and at a very poor conversion rate of kcal.

Creating 100w is killer. I'm good with about 40w max for about 20 minutes max, but I'd be straining pretty hard. I normally output 30w to 32w for about 1 hour. Reaching 100w would probably kill me if I tried to keep it up for very long. Not that I could do it on my generator because the stressing forces would bend the mounts or motor shaft and the chain will start jumping even before I reached 50w. Of course, I'm doing this on a 12v array so the RPMs are low and the torque pretty high. If I switched to a 24v array I'd last longer I'm sure, but the watt output would be about the same overall.