i'm looking for a high quality model/minature generator about 1" x 2" in size.
it needs to be able to put out ~5V (or better) ...

anybody got any ideas on where to look ???
Andy

well?

Generators

PDF

Is this what you are looking for?

hmmm, maybe ...


i guess i should have used the correct amurican term.
i just realzied that you guys call them "Alternators" ...
Andy

i looked through the PDF and that thing is waaaay too much overkill for what i need.

my target is somewhere around ~5V and maybe 2-3 Amps ...

this thing puts out way too much and i would need a humongous voltage regulator board to go with it to get to my target range.
way too much heat generated by the VR as well.


i need something smaller and/or with less output ...
Andy

How about something like this?

Genesys

Amps don't affect components like volts and watts. You only use the amps that you need and it gives you the capability to expand your loads in the future. Volts can be regulated with a resister.

i know, but if the initial low-rpm output is too large, regulating it down will create a lot of heat, which is not desirable for my application ...

something with lower initial output would work much better for me ...
Andy

much better!

hmmm ... reading the PDF right now ...
Andy

What is the intended use?
Is it used in a car?

nope, not car related. i need something for a small model that needs a constant power supply without the dead weight of batteries ...
Andy

Try a RC electric model motor the 05 comes to mind, although its a motor
it also can be used for a generator.

Andy, you are still cryptic.
What is the power source that you will be using?
You must be getting the energy from somewhere. Like a motor of some sort? Or a high temperature heat source? Or solar panel. Does it have to be light weight, portable?
Then you want to convert it to 5 volts DC? at 2 to 3 amps, so about 15 watts?

I believe that any DC motor, when driven, will create voltage.

How much, I know not.

i'm cryptic because i can't talk about details of the project (unless i want to pay a hefty fine or spent time in jail) ...

yes, it will be driven by a motor of sorts. yes, i needs to be small. yes, it needs to be lightweight. yes, heat is bad.

output needed is ~5V and 2-3 amps. anything above that will result in additional heat when regulated down, which is not desirable ...

why does it matter what drives the alternator ???

give me something small that is known to work well, please!
i'll buy you a beer or two if this pans out ...
Andy

OK I'll bite....

at how many RPM's?
and how much torque is available?

My best friend is a robotics freak/electronics guru.... maybe he knows.

Well, if you're not interested in the drive source, then use an electric motor. Spin the motor shaft, viola, power on the wires.

http://www.instructables.com/id/Lego-Generator/?comments=all

Go to RadioShack or any other electronics store (Frys?) and pick up a small motor.

Exactly.....

or just bring a volt meter and start test spinning different DC motors with the volt meter attached. Prolly bring a friend to make things easier... LOL

Hi Andy, try these people http://www.sullivanproducts.com/ They make a set up

to charge batteries in flight.


"i just realzied that you guys call them "Alternators" ..."

Only if they put out 'AC', Gen's 'DC'

If you do end up with a higher generated voltage than what you need, a step-down or buck switching regulator is the ticket. Efficiencies approaching 95% are possible to minimize power loss and heat buildup. Depending on whether you need a regulated voltage, it is common to generate a voltage higher than needed, then step it down with a high efficiency switcher.

If you have your cell phone or iPod with you then you have probably 4 to 8 switching regulators with you. Every cell phone, PDA, Blackberry, iPod, MP3 player, camera has switching regulators to maximize battery life. Li-Ion batteries generate 4.2V and this must be stepped down to 3.3V, 2.5V, 2.0V, 1.2V, or even 0.8V for low voltage low power logic.

Maxim, Linear Tech, TI, Monolithic Power to name a few offer step down switchers in the 1-2 amp range in very small packages.

The power burning regulators you mention are linear regulators and do burn considerable power. Their efficiency is approximately Vout/Vin. For the example above, Vout = 2V, Vin = 4.2V, therefore efficiency for this would be less than 50%. Not good if you want to conserve battery life and minimize heat buildup.

There are many ways to generate electricity, and an alternator is just one.
Thermoelectric is one that I am working on.
The S660 as mentioned might be a good method, but at $100 for 4 watts capacity it is not exactly cheap. If you need 16 watts, that is $400 (maybe less) plus lots of fabrication. They don't say what the maximum capacity of the controller is.

i see what you meant. well, i can't really say too much about the project (patent pending and i signed a NDA) ...

but, there is a moving (rotating) part from a motor of sorts, so i thought a small model generator would be the best/easiest to get a steady current produced.

i think i will try to use some model electric motors like mentioned above. the lego wheels motor looks intriguing ...
Andy

Use a permanent magnet motor and watch the RPMs. You will need a load that is about the same as your actual load for testing. Lots of black magic involved.

Is the 2-3 amps a startup or intermittent current or steady state current?

Edmonds Scientific:
http://scientificsonline.com/product.asp?p...hcd2=1200528427
or just go to any online robitics supplies and find an engine/generator.
Probably many being sold on Ebay.

Cooley