The video shows the guy hitting the "generator" and producing a momentary peak of 188mA but a voltage of almost zero. Then the momentary power is 188mA x 0= zero. If he continues hitting the generator then since he did not show it powering anything useful then it is simply a waste of time.

I believe he hit it just to demonstrate that the vibration would create energy as opposed to letting it sit there and waiting around and editing video.

He has an adjustment in its “artificial muscle” that I believe might help it resonate with different vibrational frequencies naturally ie without him hitting it.

I would like to try a modified version along with some scale (series and parallel) attached to a battery.

Sounds like I might either need some diodes to rectify into DC or a transformer?

 

I’m looking for side to side movement and yes the magnet will be very close.

If I could fine one already built and cheap I’d be happy to use it.

I was thinking about something either like this:

10pcs Adjustable High-Frequency Ferrite Core Inductor Coil 12T 0.6uh-1.7uh Adjustable Inductor https://www.amazon.com/dp/B083LSMZVG/ref=cm_sw_r_cp_api_i_l9FeFbV6GPR5B

OR would a toroidal work better maybe like this:

DIYhz 20 Pcs Toroid Core Inductor Copper Wire Wind Wound 100uH 6A Coil for LM2596-100uH https://www.amazon.com/dp/B07CMGTC3C/ref=cm_sw_r_cp_api_i_p.FeFbWSSHJE3

OR, maybe even something like this:

50ea Fixed Shield Inductor 100uH chip Inductor Surface Mount Wire Wound Inductor 10X10X4mm Transformer https://www.amazon.com/dp/B079NLP96Z/ref=cm_sw_r_cp_api_i_MaGeFb0PPWCCW

Essentially, the magnet may be fixed to it with rubber in between where it then sort of wobbles from vibrations.

I would totally get one already made, I just don’t know what to look for specifically.

Hello again,

Just a heads up, a toroidal core probably wont work at all because most of the flux is confined to inside the core and without a gap there is no way to get a significant amount of flux inside. For something like that you would probably need at least an 1/8 inch gap or something like that. The magnet would then be moved in the vicinity of the gap.

Same with the shielded inductor. The core is made such that most of the flux is confined within the core and that means it is also hard to get a flux inside the core from anywhere external to the core.

So you want to avoid cores that form a complete circular path. One end of the core must be open and exposed so that the magnet can generate a flux within that core when it is moved.
This is very similar to a loop of copper wire where you want to inject a significant amount of current using a current alone (not a magnetic field). If the loop is continuous so that one of the ends of the wire connects directly to the other end, there is no way to inject current using current alone (again not a magnetic field as this is a purely electrical analogy). You need to open the loop and connect it to a current generator (or battery for example).

Small values like 2uH probably are not going to do much either but there is a question this brings up. That is, how fast is your magnet going to be moving side to side? This is a very important question because the slower it moves the higher the inductance value you need (or more turns of wire).

 

Hello again,

Just a heads up, a toroidal core probably wont work at all because most of the flux is confined to inside the core and without a gap there is no way to get a significant amount of flux inside. For something like that you would probably need at least an 1/8 inch gap or something like that. The magnet would then be moved in the vicinity of the gap.

Same with the shielded inductor. The core is made such that most of the flux is confined within the core and that means it is also hard to get a flux inside the core from anywhere external to the core.

So you want to avoid cores that form a complete circular path. One end of the core must be open and exposed so that the magnet can generate a flux within that core when it is moved.
This is very similar to a loop of copper wire where you want to inject a significant amount of current using a current alone (not a magnetic field). If the loop is continuous so that one of the ends of the wire connects directly to the other end, there is no way to inject current using current alone (again not a magnetic field as this is a purely electrical analogy). You need to open the loop and connect it to a current generator (or battery for example).

Small values like 2uH probably are not going to do much either but there is a question this brings up. That is, how fast is your magnet going to be moving side to side? This is a very important question because the slower it moves the higher the inductance value you need (or more turns of wire).

Thanks, and that is a good question about how fast, but I honestly have no idea, I’m guessing it is moving fairly quick back and forth in the tiniest of distance.

Any names of possible inductor types I can look up?

 

I am looking for an inductor and magnet setup, where when the magnet moves relative to the inductor creating DC.

Im sure you might have a ton of questions for me, but as a beginner, I don’t know what to provide.
Ultimately, a couple links of a neodymium magnet that would work well with an specific inductor... not sure if I would need a toroidal or what.

I will likely make several of these andput them in series and in parallel.

I’m and looking for cheap and small, where a multitude of them will end up creating a lot of power.

Not sure if this is possible, but thought this was a good place to start a discussion, I’ve tried to do some research but it’s def a little hard to digest and understand.

What is it you are trying to accomplish?

What is "a lot of power" as far as you are concerned? 100 μW? 100 mW? 100 W? 100 kW? 100 MW? What?

What is "a multitude of them"? A dozen? A thousand? A million? What?

 

What is it you are trying to accomplish?

What is "a lot of power" as far as you are concerned? 100 μW? 100 mW? 100 W? 100 kW? 100 MW? What?

What is "a multitude of them"? A dozen? A thousand? A million? What?

For right now, one unit, with a bunch in series and parallel to see what amps I can get around 12v or 24v DC, but I guess if it turns out to be A/C to needs to be rectified/converted, then that’s more I will have to figure out.

I’m not asking for how many, but I guess I can give a constraint of inductors being 1” or less in size for all its dimensions.

 

Haven't seen one in a while but there was a 2 D cell sized flashlight that worked by shaking it back and forth to charge it. Never tore one apart but assumed it was a magnetic rod and coil design that charged up after a moderate number of cycles and kept working for a while after shaking. Interesting device. Not sure if it was LED or not. I do remember seeing the old military hand-cranked generators for tube radios.

I have one of those and it is essentially useless.
The coil is fixed and when you shake it a magnet moves back and forth inside the coil. This feeds a bridge rectifier, then a rechargeable cell and finally an LED.

There's a much better use of all that hand motion.

 

For right now, one unit, with a bunch in series and parallel to see what amps I can get around 12v or 24v DC, but I guess if it turns out to be A/C to needs to be rectified/converted, then that’s more I will have to figure out.

I’m not asking for how many, but I guess I can give a constraint of inductors being 1” or less in size for all its dimensions.

The phrase "one unit, with a bunch in series and parallel" makes zero sense. If you only have one unit, how can you have "a bunch" in series and parallel?

Again, what is it you are trying to accomplish?

This is like me asking you what car I should get if I want it to carry a lot. How can you answer that question unless you know whether "a lot", to me, is ten bags of groceries or ten cubic yards of dirt?

You say you want "a lot of power". Power is measured in watts. How many watts is "a lot of power" to you? If you can't answer that, then you aren't ready to start designing or buying anything because you have no idea what it is you are trying to do and hence no idea whether what you design or build with come close to doing what you want. So the first step is to answer that question and for that you should consider what it is you want to use this power for. So what is it you want to use this power for?

 

Maybe TS does not know how much is 1W.

Let us put some numbers to it.
A red LED needs about 5mA @ 2V to light up.
Power = Amps x Volts = 5mA x 2V = 10mW

Moving a magnet in a coil of wire by hand is going to generate about 10μW.
You are not going to generate enough power to get an LED to light up. You would need about 1000 such generators to get an LED lit.

 

The phrase "one unit, with a bunch in series and parallel" makes zero sense. If you only have one unit, how can you have "a bunch" in series and parallel?

Again, what is it you are trying to accomplish?

This is like me asking you what car I should get if I want it to carry a lot. How can you answer that question unless you know whether "a lot", to me, is ten bags of groceries or ten cubic yards of dirt?

You say you want "a lot of power". Power is measured in watts. How many watts is "a lot of power" to you? If you can't answer that, then you aren't ready to start designing or buying anything because you have no idea what it is you are trying to do and hence no idea whether what you design or build with come close to doing what you want. So the first step is to answer that question and for that you should consider what it is you want to use this power for. So what is it you want to use this power for?

As I explained, series and parallel would entail “a bunch”, my goal of one unit is essentially how many in series I will need to get approx 12 or 24v dc, and then how many in parallel I can fit in my housing that will be as long as I want and see how many amps/milli I get out of that one unit, let me worry about how much power and scaling.

what I’m not exactly sure about is if it’s generating A/C and what voltage/amps I might need to charge let’s say 12v car batteries and what I might need to do to convert it whether it’s a transformer or rectifier/diodes mentioned above(scaled once again to whatever application; you don’t need to know specifics on that).

I have simply asked for an inductor reference that might be within the ball park of what I’m looking for, this doesn’t have to be an exact, perfect calculation.

I would like the diameter of the inductor to be within less than 2” and the height be less than 1” if that’s even possible and will work with how it described (close magnet, separated from inductor by rubber, essentially wiggles from vibrations and dynamic/flexible nature of the rubber it’s sitting on; don’t worry about how I might get it to vibrate; also the vibration frequency I think will be somewhat adjustable and I don’t imagine the wiggles will be more than 1-5mm in distance.)

 

PS, whoever changed the title of the thread, thank you

 

There's a much better use of all that hand motion.

True, which is why I haven't seen one for many years now. Fad item, an interesting concept, no practicality. I think it was just a physics demonstration device available from lab supply houses.

 

As I explained, series and parallel would entail “a bunch”, my goal of one unit is essentially how many in series I will need to get approx 12 or 24v dc, and then how many in parallel I can fit in my housing that will be as long as I want and see how many amps/milli I get out of that one unit, let me worry about how much power and scaling.

what I’m not exactly sure about is if it’s generating A/C and what voltage/amps I might need to charge let’s say 12v car batteries and what I might need to do to convert it whether it’s a transformer or rectifier/diodes mentioned above(scaled once again to whatever application; you don’t need to know specifics on that).

I have simply asked for an inductor reference that might be within the ball park of what I’m looking for, this doesn’t have to be an exact, perfect calculation.

I would like the diameter of the inductor to be within less than 2” and the height be less than 1” if that’s even possible and will work with how it described (close magnet, separated from inductor by rubber, essentially wiggles from vibrations and dynamic/flexible nature of the rubber it’s sitting on; don’t worry about how I might get it to vibrate; also the vibration frequency I think will be somewhat adjustable and I don’t imagine the wiggles will be more than 1-5mm in distance.)

Think about it from a power standpoint. You want to charge a car battery. Okay, consider that a car battery can crank an internal combustion engine on a track, against the full compression of the engine, for quite some time. Could you do that by wiggling a stick? Well, if you are going to take the energy you impart to the stick by wiggling it and use that to charge the car battery, which is doing nothing but storing the energy you imparted to the stick, and then using that to crank a truck engine, then you start getting an idea of how absurd the notion is.

 

Thanks, and that is a good question about how fast, but I honestly have no idea, I’m guessing it is moving fairly quick back and forth in the tiniest of distance.

Any names of possible inductor types I can look up?

Ok, well then what exactly is causing this movement?

This is starting to sound like a very stringent application. That probably means you have to do some custom design to get anything to happen even close to what you want to happen. It also means some experimentation would be necessary in order to ascertain what works and what doesnt. We do have those general guidelines i outlined previously though so that would help, but you probably have to buy a core material and maybe a coil form and wind some turns, then see what you can get out of it when you connect and mount everything. If it does not provide enough output then you may have to get a different core and try again, or wind more turns.

I will take a look around the web and see if i can find an inductor that might work, but without knowing how fast your magnet is going to move it will be hard to decide, and most inductors are made so that they have their flux mostly confined inside the core so that they can have a decent efficiency.
I'll look around but i think you are going to have to start with a core and wind turns and go from there. You would just get one core to start that you can use in your experiments. Once you get something to work you can always buy more of the same thing.

I would also try to get the strongest magnet available that fits your budget.

Is there any way you can provide a diagram of what the setup is going to look like? That would help a lot i think. Be sure to show what is going to be making the movement of the magnet.

 

You need to learn some basic physics of electromagnetic induction.

If you have a magnet surrounded by a loop of wire the current induced is zero.
In order to induce a current the magnetic flux must be changing.



The induced voltage and current is determined by Faraday's Law of Induction.

v = iR = -NA dB/dt

where v = induced voltage
N = number of turns in the loop
A = area of loop
dB/dt = rate of change of the magnetic flux

The voltage is DC as long as the magnet is moving in the same direction.
That is the problem. How long can you keep moving the magnet in the same direction? Soon or later you have to pull the magnet back. Then the voltage and current will reverse resulting in AC.

 

Think about it from a power standpoint. You want to charge a car battery. Okay, consider that a car battery can crank an internal combustion engine on a track, against the full compression of the engine, for quite some time. Could you do that by wiggling a stick? Well, if you are going to take the energy you impart to the stick by wiggling it and use that to charge the car battery, which is doing nothing but storing the energy you imparted to the stick, and then using that to crank a truck engine, then you start getting an idea of how absurd the notion is.

You have made a lot of assumptions and I’m not going to get into them all, but for example, just cause I said car battery doesn’t necessarily mean I’m going to use it to power a car.

Anyway, I’m not trying to debate the feasibility of anything, it also involves explaining a lot of extra stuff, I’m merely trying to ballpark determine one aspect of it for now. I will then experiment and I can share some findings from there.

 

Ok, well then what exactly is causing this movement?

This is starting to sound like a very stringent application. That probably means you have to do some custom design to get anything to happen even close to what you want to happen. It also means some experimentation would be necessary in order to ascertain what works and what doesnt. We do have those general guidelines i outlined previously though so that would help, but you probably have to buy a core material and maybe a coil form and wind some turns, then see what you can get out of it when you connect and mount everything. If it does not provide enough output then you may have to get a different core and try again, or wind more turns.

I will take a look around the web and see if i can find an inductor that might work, but without knowing how fast your magnet is going to move it will be hard to decide, and most inductors are made so that they have their flux mostly confined inside the core so that they can have a decent efficiency.
I'll look around but i think you are going to have to start with a core and wind turns and go from there. You would just get one core to start that you can use in your experiments. Once you get something to work you can always buy more of the same thing.

I would also try to get the strongest magnet available that fits your budget.

Is there any way you can provide a diagram of what the setup is going to look like? That would help a lot i think. Be sure to show what is going to be making the movement of the magnet.

Thank you, I will try to draw some diagrams very, very rough lol

 

You need to learn some basic physics of electromagnetic induction.

If you have a magnet surrounded by a loop of wire the current induced is zero.
In order to induce a current the magnetic flux must be changing.

View attachment 212390

The induced voltage and current is determined by Faraday's Law of Induction.

v = iR = -NA dB/dt

where v = induced voltage
N = number of turns in the loop
A = area of loop
dB/dt = rate of change of the magnetic flux

The voltage is DC as long as the magnet is moving in the same direction.
That is the problem. How long can you keep moving the magnet in the same direction? Soon or later you have to pull the magnet back. Then the voltage and current will reverse resulting in AC.

I def am no expert and am the first to say it, thread originally title me as a beginner.
The A/C aspect is what I’m also definitely trying to see if it’s possible to get around by design without having to convert later to DC later.

 

Going from AC to DC is the least of your problems.
Your biggest problem is what are you going to do with 10μW of power?

 

Thank you, I will try to draw some diagrams very, very rough lol

That should be fine, just try explain what the parts are and what they have to do.

Also, if the movement is too small you may have to move into piezoelectric generation instead of electro magnetic.

There is also a chance that you may have to face the fact that this may not work at all no matter what you do simply because there just isnt enough energy in the movement you are talking about. Some applications just dont generate enough energy on their own and in those cases we usually see sensors that may generate tiny signals but not large power levels that can say toast white bread or even run a power LED.

 

If you want to talk about ultra-low voltage energy harvesting that is a different path we can go down.