Author Topic: Small Generator  (Read 765 times)

Offline Robert Hornby

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Small Generator
« on: September 21, 2021, 07:36:22 AM »
I have started a simple Wobbler engine based on J De Waal design. I am thinking I would like it to do something rather than just go around and around. May I request some thoughts on this generator ?

https://au.banggood.com/FD-3-Machined-Dynamo-Small-Generator-for-Steam-Engine-Model-p-1578461.html?cur_warehouse=CN

And how fast do I need to have it rev to power 3 or 4 LED's ?

Bob

Age and treachery will always overcome youth and skill

Offline pieterb

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Re: Small Generator
« Reply #1 on: September 21, 2021, 08:52:17 AM »
Hello Bob,

I don't know anything from the banggood generator but a few years ago I made a 3D printed air engine with a DIY generator. We blew up some LED's due to high voltage from running to fast. At some point we made over 100V (no amp's of course). So more than enough power for some LED's. Below a link to the video we posted on youtube

<a href="https://www.youtube.com/watch?v=8KOpkGANEJg" target="_blank">http://www.youtube.com/watch?v=8KOpkGANEJg</a>

Offline Roger B

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Re: Small Generator
« Reply #2 on: September 21, 2021, 07:29:23 PM »
Most small permanent magnet motors from toys etc. will work as generators for small engines. You can drive them with a lathe or drill to see what speed they need for what output. 
Best regards

Roger

Offline Bluechip

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Re: Small Generator
« Reply #3 on: September 21, 2021, 08:32:02 PM »
Looks very much like a Mabuchi ( or more likely a clone / copy ) motor fitted with a lump of alloy machined  to resemble a generator.
19$ seems a bit extravagant .... for what it is.
As Roger says any PM motor will generate.
What you get out is somewhat empirical. I have one similar ( NOT the same  :ThumbsUp: ) to this:




https://cpc.farnell.com/velleman-sa/mot2n/dc-motor-6vdc-250ma-14500rpm-2/dp/MC02199

It chucks out some 4V @ circa 2k RPM. Belated edit .. this is NO LOAD Volts

LEDs require some 2.6V to 3.8V / 4V ( typical ! ) or so depending on the colour.  (or color   ::)  )
In ascending order red, orange, yellow, green, blue, white, ultra violet .

Assuming the bog standard 5mm LED you're looking at a current of about 10 - 15 mA. or so.

The question as stated doesn't really have an answer.  :ThumbsUp:

Once you have a 'motor' and some idea what it chucks out re: volts and at what RPM you can then decide if you need a voltage regulator chip, series dropper resistor and of what value  or whatever.

Dave



« Last Edit: September 22, 2021, 10:19:49 AM by Bluechip »

 

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