Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

project small generator 3

Status
Not open for further replies.
if we know how to measure the AMP, Hz.....
PS: It is not our purpose to teach the ETO' S members, they are overqualified for this homemade project - probably a school project for them. We wish to learn from them if it is possible..... to improve it by increasing the voltage only, keep the small dimensions and keep the purpose. If it is posible to resume to the voltage only - I know voltage is not important for you without AMP, Hz... . I posted already the construction details. It is a homemade project.
thx for the help : sciencetoolbar
 
We wish to learn from them if it is possible..
Then presumably you tried the changes suggested by LittleGhostman, i.e changing the shaft length? What effect did you notice/measure? What is the effect of removing the spherical magnet altogether?
 
the actual plastic holder witch cover the motor ax at one end and cover the metal screw " plate" at the other end is 1.5 cm - without the metal "plate" hight wich is fixing the sphere) ( "small generator 2" movie ) , if we will make it shorter, the magnetic sphere will be to close from the metal case of the motor and we will lost power (the attraction between them), if it will be longer than 1,5 cm the existing oscillate will increase and the sphere it moves from the initial position, relative small voltage, of course it is a handmade holder so it is not centered well. we heat the plastic to put the metal screw with "plate" (ex screw neodymyum magnet - just the case of it)

thx st
 
You are missing all the points! So I am going to try one last time......................

Amps matter (Alot), if you want to learn then we need the figures. You are making wild guesses and assumptions and they are not accurate, what is going on is not what you think it is. I went through the whole thing myself when I started playing with electro motors etc, If you measure the Amps then we can show you how to make higher voltage and maybe make it more efficient.

The problem at the moment is my tests show that the first video couples with your motor, no doubt about it. If I hook a scope up to the output of the coil, and if I read the motor RPM, then what I see on the oscilloscope is a frequency that pretty much matches the motor. This was done without any magnet on the motor! Adding the round magnet made it slightly more efficient, but voltage was roughly the same. I am not sure how this side of things works, inductive coupling is complex. But if I had to make a few guesses then I would assume that the small magnet acts as a kind antenna (not the correct word), or it alters the resonate frequency.

If all you want to do is up the voltage then simply put a voltage doubler made with a couple of diodes and caps on the coil. the voltage will double and your light should still light. But you will have learnt JACK ****.

You may want to concentrate on the voltage, but I got some really bad news for you. This is lesson One if you like.................

In electronics/electrics is a family, this family does everything together. They will NOT operate separately!!!

One is the lanky tall weak one, we call him Voltage.

One is the smaller but beefier Brother, we call him Amps

And one is stubborn and resists most things, we call him resistance.

Now they only work as a trio, worse still they will only play with you if you use a set of rules called Ohms Law.

What I am saying is, you cant work with voltage and ignore the others. In your case the main one you also need is Amps, unless you measure this you wont know much. Your leds are not running at 7W (sorry), just cos it says 7W on the side dosnt make it so. They are leds and therefore a Current device not a voltage device like a bulb is. To light a led you need anything from 1 mA -750mA (high power ones). So you might be knocking out 200V, But you might only be putting out ~40mA. Double the voltage to 400V and your Amps would be 20mA.

These are extremely rough numbers, you are not getting 40mA ;), but what I am saying is we cant help or teach unless you learn, part of learning is excepting that maybe what you think is true, isnt true.

I bet you used to think the Easter bunny was true, or Santa was true. Then you find out that only Santa is true. Well your kind of at that point at the moment. So go take the numbers, you measure Amps inline, that is the meter forms part of the circuit. I will google something for you later. Follow that and give us the numbers.

But seriously stop being stubborn if you want to learn, having played with this over the last few days, I can assure you that actually something way more interesting than a generator is going on. I can also show you a few cool things to do with your set up. But there is zero point without you measuring, all it would be is a party trick and a waste of time. If you learn to use the multi meter to take readings, then we can show you how this generator works, we can also show you how to fine tune it.

Last chance or your wasting my time.
 
"having played with this over the last few days, I can assure you that actually something way more interesting than a generator is going on" please explain that phrase . Don.t wish to waste time. this is the meaning of the educational " school project" maybe someone will observe something else much more interesting. I will measure the values... again ....and I will wright them. who said I don't know how to use a multimeter? I didn't said that
 
Last edited:
As I promised:
3,7 V 600 mAh batery ( small generator 2" the movie) Dc 3.0 V motor

dc motor without load ( without E27 230 V 7 W ) - 0.11 A
dc motor with load - 0,48 A

thx st
 
If you watch the video's I posted basically what your seeing is resonance being reached in a coupled system. Because I dont have all your data I cant be sure, but in my tests I was able to reproduce your first video. It wasnt easy though, what I found was the motor magnetic field reached the same resonance as the coil. I am no expert on this by a very very long way, so some of this might not be 100% correct.........

What I think you did was manage to inductively couple your motor to the coil, so the coil and lights were being powered by the magnetic field of your motor, and not directly by the field from the coil and magnet alone. This is interesting because to be frank....Any idiot can make electric with a magnet and coil, its not rocket science. But to me, blindly stumbling on the right combination to magnetically couple the motor and coil is pretty neat.

Alot of people try and inductively couple, it is a way of wirelessly transferring power if you like. Its is pretty inefficient and the sweet spot is hit when you have everything in resonance.

But while I know my test at least once hit this spot, I have no idea about yours because we dont have the numbers! What interests me is the use of the magnet to help induce the right resonance, as you see in the video normally the magnet spins. But please dont go thinking that little magnet inside the coil produced the voltage! It may well have helped sync everything up etc but the magnet alone did very little. That is why I said to spin the magnet on a longer shaft so the magnet was in the same spot as before, but the motor was away from the coil field.

That would prove conclusive if your magnet or the the motor was actually inducing the Voltage.

If it is the magnet alone then this is what should have happened in my test..................

Move the motor further away and magnet held in same place, the voltage dosnt change. That means yes the magnet produced all that voltage from the coil and you disproved current theory that square is better than round. Especially significant as some wind turbine generators use square magnets rotating over the coils, they exactly fit the diameter of the coil. As this produces the most current and Voltage. So if I had seen that happen it would mean there is a better way for these generators.

BUT I didnt get that, when I moved the motor away from the coil, but kept the magnet spinning in the same place as before, the Voltage dropped significantly. So where did the voltage come from???

The clue is in the first Video you posted, because you used a ball magnet it should have stopped dead under load. The motor shaft should have kept turning. But instead the motor changes pitch like it would do under load. Ahha!!! Clue 1

Why was the motor under load when the ball could easily spin on its own without affecting motor speed? Simples........The motor is under load because in that video it is the motor and its magnetic field that is actually inducing the Voltage in your coil, so when you load down the coil with the light, you load down the motor!

So go get all the measurements I asked for and we can work on making your inductively coupled motor more efficient! You might find a nice easy way (although noisy!) to inductively couple. Also would mean I could use my Big Ass out runner BLDC rated at 12000K to produce some serious voltage in a coil (within reason), but more importantly makes finding the sweet spot alot easier as all you got to do is alter the motor speed until you hit resonance.

That in a nutshell is why I think its interesting. But as a generator it sucks. Dont feel bad all generators like this suck, generators in general suck. Its part of life that they are inefficient which is why SMPS was invented :D, because while that also sucks, it sucks significantly less than a transformer or generator.

But we dont talk about SMPS because it invokes Flyback to appear, and you dont wanna do that! Especially as your using lighting
 
As I promised:
3,7 V 600 mAh batery ( small generator 2" the movie) Dc 3.0 V motor

dc motor without load ( without E27 230 V 7 W ) - 0.11 A
dc motor with load - 0,48 A

thx st
what are the coil readings at the same time?
 
There is the proof for you, if the magnet is just stuck on with magnetism then the motor should show ~4X the loading should it ;), the motor should show a little increase but the magnet should alter speed or stop.

So it looks like you did indeed inductively couple the two.
 
So your pulling roughly 1.7W from the power source.

If we now know the Amps from the coil side we can see how many Watts your transferring.
 
Oh and go careful...........200V+ even at 30mA isnt nice.
 
So hook the meter up in the path from the coil to the leds, dont do it on the motor/magnet side
 
I reached 180V @ 65mA using a bigger coil and motor, but that is getting to places we want to stop and think. Dosnt take as much as you think to kill. My own rule of thumb for me personally is 50V @50mA and I start to be careful. The bonus though in this case is the Voltage is alternating and not pure DC. Well ok its not a sign wave exactly but it isnt straight DC. So I dont know what would be dangerous, therefore we treat it as dangerous for now. Saves the expense of a funeral.
 
Oh I am sure my figures are a bit off, I did head calcs :D, so expect one the clever people who what they are talking about, to actually give the accurate figures, but I am roughly in the ball park (I think).
 
HINT

The reading wont be 0.00000000000A I can guarantee that ;)
 
I've tried to measure the Amps on the coil side and the multimeter read 0.00. I don't know why I'm seeing this, maybe I'm working with a non proffesionall multimeter. Maybe if I had a Fluke multimeter I would probably see something. please try to reproduce my experiment and if you have a better multimeter you are welcome to try. keep us updated.

PS: I've tried 3 multimeters
thx st
 
PS: It is not our purpose to teach the ETO' S members, they are overqualified for this homemade project - probably a school project for them. We wish to learn from them if it is possible.....

No one's overqualified to learn anything new. If anything when teaching kids new things overqualified help is exactly what you want overseeing the educational process.

As is there are too many improperly taught people who have incorrect understandings and beliefs in too many areas of well understood and defined science in the world today and no one needs to be adding more fuel to that fire.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top