HELP- I feel like I should be producing enough power with this wind turbine to light a red LED. Why am I not able to?

Boggart

Joined Jan 31, 2022
53
I should add that polarity is not the issue.
What's the voltage coming off the motor/generator? If it isn't high enough to forward bias the LED, it won't light. Modern high brightness red LEDs need around 1.6V to start illuminating, up to 2.2V to reach full rated forward current.
 

Thread Starter

WoolyMamit

Joined Sep 10, 2022
10
What's the voltage coming off the motor/generator? If it isn't high enough to forward bias the LED, it won't light. Modern high brightness red LEDs need around 1.6V to start illuminating, up to 2.2V to reach full rated forward current.
The voltage is around 0.5v. It just confuses me when I see a guy like this power a full led strip.
 

Thread Starter

WoolyMamit

Joined Sep 10, 2022
10
What's the voltage coming off the motor/generator? If it isn't high enough to forward bias the LED, it won't light. Modern high brightness red LEDs need around 1.6V to start illuminating, up to 2.2V to reach full rated forward current.
Also Ive been told that 100-200 rpm should be enough to reach the voltage threshold on a 3v dc motor like mine, and I feel like mine is spinning at atleast 100-200 rpm.
 

Boggart

Joined Jan 31, 2022
53
Also Ive been told that 100-200 rpm should be enough to reach the voltage threshold on a 3v dc motor like mine, and I feel like mine is spinning at atleast 100-200 rpm.
No, those little motors are made in a range of speeds, there are low speed and high speed models, you need a low speed model, what are often referred to as "solar motors".

But here's a trick, get yourself a small stepper motor, they produce high voltages across their output wires when used as a generator, if you get the right one they will have minimal cogging. Old computer floppy drives are a good source of small steppers. Then, connect two LEDs in reverse-parallel across any two of the phases and you will be good. The LEDs will appear to flicker at low rotational speeds, but as the motor speeds up the flashes will be so fast that persistence of vision makes them look like they are solidly illuminated.
 

Thread Starter

WoolyMamit

Joined Sep 10, 2022
10
No, those little motors are made in a range of speeds, there are low speed and high speed models, you need a low speed model, what are often referred to as "solar motors".

But here's a trick, get yourself a small stepper motor, they produce high voltages across their output wires when used as a generator, if you get the right one they will have minimal cogging. Old computer floppy drives are a good source of small steppers. Then, connect two LEDs in reverse-parallel across any two of the phases and you will be good. The LEDs will appear to flicker at low rotational speeds, but as the motor speeds up the flashes will be so fast that persistence of vision makes them look like they are solidly illuminated.
Would these be good? https://www.amazon.com/dp/B07Q44YYKG?psc=1&ref=ppx_yo2ov_dt_b_product_details
 

Thread Starter

WoolyMamit

Joined Sep 10, 2022
10
No, those little motors are made in a range of speeds, there are low speed and high speed models, you need a low speed model, what are often referred to as "solar motors".

But here's a trick, get yourself a small stepper motor, they produce high voltages across their output wires when used as a generator, if you get the right one they will have minimal cogging. Old computer floppy drives are a good source of small steppers. Then, connect two LEDs in reverse-parallel across any two of the phases and you will be good. The LEDs will appear to flicker at low rotational speeds, but as the motor speeds up the flashes will be so fast that persistence of vision makes them look like they are solidly illuminated.
Or these? https://www.amazon.com/Bemonoc-10Pc...1&s=hi&sprefix=solar+dc+motor,tools,58&sr=1-4
 

MisterBill2

Joined Jan 23, 2018
13,126
The TS states that "polarity is not an issue", but certainly it is an issue if it is not correct. So how does the TS know that the polarity is not the problem?? Did they check with a voltmeter and verify polarity??
 

Thread Starter

WoolyMamit

Joined Sep 10, 2022
10
The TS states that "polarity is not an issue", but certainly it is an issue if it is not correct. So how does the TS know that the polarity is not the problem?? Did they check with a voltmeter and verify polarity??
I have checked polarity with my multimeter. I am not producing enough voltage, but my issue arise when I compare my imgur video to the youtube video that I posted. I feel as if I should be producing more than 0.5v.
 

Boggart

Joined Jan 31, 2022
53
I have checked polarity with my multimeter. I am not producing enough voltage, but my issue arise when I compare my imgur video to the youtube video that I posted. I feel as if I should be producing more than 0.5v.
Motors have an rpm/volt rating, so if you have a motor rated at, say, 1800rpm at 3V, then that's 600rpm/volt, which means that if you spin it at 600rpm you will see around a volt of output, maybe.

So, what you want is a low speed motor with a higher voltage rating. For example, a 12V, 1800rpm motor is rated at 150rpm/volt, much more usable. Or even a 24V motor...
 

Boggart

Joined Jan 31, 2022
53
I forgot to mention, forget amazon etc, check out the electronics surplus stores, they often have a good range of small motors. Electronic Goldmine does, the others probably do too.
 

WBahn

Joined Mar 31, 2012
27,392
I have checked polarity with my multimeter. I am not producing enough voltage, but my issue arise when I compare my imgur video to the youtube video that I posted. I feel as if I should be producing more than 0.5v.
What is the basis for believing that the video you are watching is legit? Tons of faked videos out there, so why are you accepting this one at face value?
 

Boggart

Joined Jan 31, 2022
53
What is the basis for believing that the video you are watching is legit? Tons of faked videos out there, so why are you accepting this one at face value?
Regardless of whether the video is faked or not, using small motors as generators is one of the first things most experimenters try, it works fine if you have the right motor...
 

Boggart

Joined Jan 31, 2022
53
One thing I remember when messing with DC motors many years ago was the old tape drive motors from the big vertical computer tape drives, they were about 100mm diameter and up to 250mm long, big permanent magnet motors. They were amazing generators, and you could hook two together and if you turned one a half turn, the other would follow, turning a bit less because of losses, of course. It was quite impressive, you don't get many good permag motors like that from surplus stores nowadays, even here in Australia we used to pick them up for $20.
 

Boggart

Joined Jan 31, 2022
53
I just want to thank you for being such a massive help!
No problem, check out goldmine, I'm on there now actually, hadn't been there in a long time and they have some cool stuff if you look in the clearance and sales sections. There are several other big surplus places in the US that also have interesting stuff, forget their names now though.
 

Boggart

Joined Jan 31, 2022
53
Oh, forgot to mention, some motors have little speed controller boards in them, often used in cassette players and the like, the speed controller was used to trim the play speed to the correct rate. You don't want those as they won't work as a generator most likely, the onboard electronics blocks the output.
 
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