# Question...transformer

Discussion in 'General Electronics Discussion' started by elwood770, Mar 17, 2010.

1. ### elwood770

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Mar 17, 2010
I'm not much of a dabbler in the electronics department but it is one of the things that fascinates me and on occasion I play. I recently did a project for my communications class and built a model of a wind generator which kinda sparked an interest again. I have a few questions...The output from the generator was between 1 and 1.5 volts, enough to light a LED and a few times it struggled to light two. I couldn't find a transformer in the local Radio Shacks that would work and one of the guys suggested that I make one somehow but he couldn't tell me how. How would I make a transformer that would jump it up to around 5 volts? I've done some research online but all the things I find seem to involve an input of 12v or more, which I clearly don't have or need. I understand the winding ratio but the core seems to escape me. Can I use a paper clip?

Also, the input fluctuated so the output would then fluctuate. How do I regulate the output voltage to be more constant and to not go over a certain voltage? I don't want to blow the LEDs just light a few more.

2. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

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Jan 21, 2010
If the output from the generator was DC (as is used to light LEDs) then a transformer won't work. If it's AC then you probably shouldn't run LEDs from it directly.

If it could light 1 LED (without blowing it up) but barely light 2 LEDs in series, this suggests the power output is very low. Adding a transformer (assuming it's AC( may increase the voltage, but not the available power. It probably won't help.

Maybe the best option is to see if it can generate enough voltage to charge a single nicad cell. If it can, then you can use the nicad to drive a LED (or several) using the types of circuits used in solar garden lights. Essentially you will be replacing the solar panel with a wind turbine. It will still mean that you need more hours of wind than you'll get hours of LED illumination.

It sounds like you're using a pretty small motor. The better suggestion is to consider using a higher voltage motor as a generator. It is more likely to generate usable power.

There are plenty of resources on the web that can give you pointers

3. ### elwood770

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Mar 17, 2010
It's a computer cooling fan motor, I believe it's a 12v. I'll see if I can find a bigger motor to get what I want. Thanks for your help.

4. ### (*steve*)¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥdModerator

25,482
2,830
Jan 21, 2010
The issue may simply be that:

a) It's not a good generator

b) it can't be spun fast enough by the wind to generate a reasonable voltage.

I've heard of people using stepper motors, maybe you could try getting an old stepper motor and scavenging a fan from somewhere. You will have to identify the leads and rectify the output though. Look here.