Turbine Powered LED's

Hoki

Hi im wondering if anybody can help me with a project im working on at the moment. Im trying to use water power to turn a turbine which in turn will help light a few LED's.

Its gonna be done in something about the size of a medium sized fish tank. The turbine will obviously have to be placed in the tank but im unsure of how big a turbine il need & how im going to pump the water to turn the turbine.

Im also curious to know whether its possible to create this kind of power in such a small tank . I had a small fan which i hooked up to my meter with croc clips & turned the fan as fast as i could but this was only generating about 0.4V so im really not sure if its a runner.

Does anyone have any idea if this can be done ?

Stoner

1) I assume that you are going to build at least one buffer into your plan??, electrically this will be a battery correct? that is charged by a turning turbine? so you can charge it and you have a switch for the LEDs? the output on the battery should be enough to light the LEDs but you can trickle (excuse the pun) charge the battery with water

2) Buffer no.2 how to get the water to turn the generator, will you will need to simulate a water source at two heights, you can do this with a pump loop where you pump water up to a higher container (buffer) and let it fall back to the lower container. You could use this falling water, a very basic consistent head of water to turn a generator. The higher water collector will be the buffer.

Or you could cheat by using the output of the pump to forcefully pump the water directly on to the generator, pretend it is a waterfall or something.

I assume that is is ok to use a mains powered electrical pump, depending on what this is for you could possibly get away with pouring the water from one container to another.

what is this for anyway, it sounds good

Hoki

Funny you should mention waterfall, its something similar im trying to recreate. I don't think a mains powered pump will do, it has to be portable so a hand powered one is what im after. Pouring from one container to the other isn't really an option either as i want to have the buffer built within the one container if you get my drift. Its going to be made out of perspex.

The idea is the water flows as a result of using the pump down to the lower part which contains the turbine. Then, like you said, it will charge a Battery which in turn will light a few LED's.

What im unsure of is :
1. The type of battery which would be suitable for this.
2. The type of turbine - I have a small little dc fan which i am toying with the idea of using but am not sure of its suitability.
3. What type of LED would this project be capable of lighting - Im presuming no more than your average miniature LED.
4. What size resistors to use with the Leds.
5. I dont know whether to use a breadboard to display the Leds or have them on their own. I realise this depends of course on my own preference!

As you can tell im still in the very early stages of this so im completely open to all suggestions!!

Hoki

Anyone have any input on the following ?

Will the Leds work with a resistor just having them connected to the leads from the small dc fan/turbine or do i need to get a battery?

Iv been testing this tonight - connecting the fan to the LED & then spinning the fan but it wouldnt light the led.

What am i missing here ? Thanks

Stoner

see here

http://www.allaboutcircuits.com/vol_3/chpt_3/1.html


what op voltage are you getting from the generator now?

you'll have to have enough voltage from the fan to break down the pn junction, in text books this is usually 0.7V but can be higher or lower than this figure, in some circuits you will need a current limiting resistor to protect the diode.

Are you getting enough voltage to drive the diode, can you now charge a battery and use it to power the diode?

Have you tested the polarity of the diode in your circuit and with a battery to see if it works?

Stoner

http://led.linear1.org/1led.wiz

this might be useful, it will help with finding the correct resistor if necessary to protect the diode, all these details should come with your diode

Add your diode details, and the battery is your generator, either that or put a battery in that circuit and charge it from then generator.

you could reverse engineer something like a bike dynamo charging a battery that in turn powers a LED
http://pilom.com/BicycleElectronics/BicycleElectronics.htm the dynamo is your generator in this case, but we don't know that the generator can do

you could try to Google around that,

what is this for anyway?

Hoki

Im getting between 30-80 ma , varies a hell of a lot with the water hitting the fan. I forgot to buy resistors today when i was getting the gear so gotta get them in the morning , thanks for that site .

Thats a good idea with adding the battery to the circuit even though im not sure it would be generating enough to charge it? Im really not sure if i can get 0.7v to break down the junction, driving me mad this project

Stoner

What is this for BTW, I'd like to know.

I have a potential quick fix that will cost you about 5 euro but i dont know if its fair to offer it.,

you can get wind powered LEDs, you could modify the blades on the turbine to do more work under falling water.

Stoner

http://www.dealextreme.com/p/wind-powered-led-light-for-vehicles-2-pack-5172

if this works you wont need a battery, just need to get the water to turn the turbine fast enough,

it should be easy to build the circuit though.

you could use the a computer cooling fan, once it has brushes, try one in reverse and measure its voltage

http://www.youtube.com/watch?v=fNXanUulfTg

Stoner

we'd look for Voltage here, measured across (in parallel, between the black and red wires)

you don't want to deal in Amps, current should be measured in series with your load, i.e break a black wire though the meter, you can break a meter measuring the wrong way. i.e black wire into meter cut , current passes through the meter and black wire continues out the other side.

Hoki wrote: »

Im getting between 30-80 ma , varies a hell of a lot with the water hitting the fan. I forgot to buy resistors today when i was getting the gear so gotta get them in the morning , thanks for that site .

Thats a good idea with adding the battery to the circuit even though im not sure it would be generating enough to charge it? Im really not sure if i can get 0.7v to break down the junction, driving me mad this project

Bruthal

Stoner wrote: »

What is this for BTW, I'd like to know.

I have a potential quick fix that will cost you about 5 euro but i dont know if its fair to offer it.,

you can get wind powered LEDs, you could modify the blades on the turbine to do more work under falling water.

Water will do more work alright for a given flow rate compared to air, but with the wind powered LED items they probably depend on the turbine blades rotating at very high rev`s. Where water would give the same power with a lower flow rate is by gearing up the turbine drive on them. Maybe they will light a little at low rev`s though, have you seen them yourself? Its an interesting one anyway.

An similar example would be the large wind turbines we see around ireland, if the same turbine was powered by water flowing at the same rate as the air over the blades, the blades would only need to be a fraction of the size of the air driven ones for the same output.

A dc motor as a generator probably works better the higher voltage it is rated for as a motor and the more poles it has, as it needs less revs to generate a given voltage.

Stoner

no i never saw them working, i'd imagine that they would need a gear arrangement alright