View Full Version : Low RPM alternator.

Rising Sun
03-30-2012, 01:03 PM
Hi Guys,

Firstly I am not expert in electronics and all ,so please reply in simple English :D

I am looking to make a cell phone charger using wind. So I need a low RPM alternator / motor, have enough torque (I guess) having wind of >= 40KMPH. I need it to be small so that I can carry it.

I am particularly looking for some 100 ~ 150 RPM motor that can deliver around 4v atleast (coz cell phone battery needs atleast 3.7 v)

So any Idea where I can get it or what its called ? If you can give me a model number it would be awesome.

Rising Sun.

Rising Sun
03-30-2012, 11:41 PM
No update ? :(

03-31-2012, 09:34 AM
Where variable DC is supplied you will have to use a step up/boost converter to give constant output from inconsistent input.

Basically use a Boost Regulator chip and step up the voltage to say 6V then pass it to a Li-ion charger IC to do the rest.

You cannot simply connect wires to charge Li-Ion Batteries.

If you simply want a 5V output use a boost regulator and with 5V output.

As for motor , buy a good DC motor from nex-robotics / probots / vegakits .

For ex -


Rising Sun
03-31-2012, 12:35 PM
Yes correct, i cant connect the wires directly, in fact I want to connect it with UPS circuit so that my cellphone also gets proper and continues power.
I have to connect a battery also to it, I am currently having a 6v battery for that purpose.

So I want to know and out line what all Ill be needing.

My theme is :

The wind turbine should generate power, using UPS circuit (with charging ) should charge the battery and from there I can use it as I want.