Another hint. The alternator is easier in the you only need two "slip rings" to get the power out of the rotor. A generator need a segmented "commutator". The slip rings need to be insulated from the shaft. One end of each rotor coil gets soldered to each slip ring and the other ends to the other ring. The coils on the rotor arms also need to be wound in the same direction, clockwise or counter clock wise doesn't matter, as long as they are the same. The same thing applies to connecting to the slip ring, the start of each coil needs to be connected to the same ring, again it doesn't matter which ring s long as they are consistent. The reason for this is called the "phase" of the wiring. An out of phase coil will cancel the other out one and give no output.

I put the quotation marks on words for you to Google, to see what I'm talking about, to help with you understanding why it matters in this.

Thank you for marking these, words this is really helpful and a good explanation, this makes everything so much easier!

 

Was just about to suggest that myself. Stationary coils and rotating magnet(s). But this will produce AC, not DC. After producing AC you would have to rectify the current to get pulsating DC voltages. A cheap meter will have a hard time measuring the voltage because during AC generation your voltages will swing fully from positive to negative to positive to negative - ongoing like that.

If you're looking to build a generator simply for learning how to make such a device, a bar type magnet with a hole in the middle, a shaft and a drill to spin the magnet. A single coil will work but two will work better. And if you've ever seen old time photographs of hydro-electric dam generators you'll see a large number of coils about the rotating magnet. That is IF they use a magnet in those old generators

I was thinking about that, but I was not able to drill a hole into the magnet so this, but since you pointed out building a stationary coil will make things easier, I will give that a shot again.

 

Now about the next problem.

Your magnets are stationary. That's ok.
The armature is the coil of wire wound around a soft iron core. This is called the rotor. This has to spin around the fixed magnetic field. There is no way to connect to the coil without getting the loose ends of the wire all wrap up around the axle of the rotor.

The way this is done on a real motor or generator is with the use of two slip rings or one split ring and a pair of carbon brushes.

View attachment 256513


SLIP RING

View attachment 256509


SPLIT RING
View attachment 256512

Stay tuned. There is still more to come!

This looks pretty hard to build from scratch but great pictures, it really explains a lot about how this generator works. Thank you for your time

 

Hi there, I am currently working on a small project and I am really not good at it, in addition to that I am pretty new to the concept of electricity (you know what I mean xD) ... I am trying to build a DC Generator. My knowledge came this far:
Electrons are attracted to the positive pole of a magnet. By spinning my rotator, my free electrons should alternate between being repelled and attracted, thus moving electrons creating a current. Unfortunately this is not working. All copper cables are connected to the axis of rotation, but my Volt-Meter is not detecting anything. I am sorry for this messy picture, I wanted to build a prototype first, in case something is not working. As it is right now. Lucky me...

Again, thank you to all of you trying to help and explain, I really didnt expect so many trying to help, I got an idea where to start Happy new year

 

Now you know that it is easier to move the magnet than to move the coil.
Now comes the big question. How fast do you need to move the magnet?

The amount of electrical power generated depends on the strength of the magnet. Yes?

A stationary magnet generates no induced current.
The magnetic field needs to be changing. The current induced is a function of the rate of change of the magnetic field. The faster it changes, the higher the induced current in the coil.

Another experiment for you to try is to wind a circular coil on an empty toilet paper roll with very fine magnet wire. You need a very large number of turns, in the hundreds or even a thousand turns.

Move a magnet in and out of the centre of the coil as fast as you can.
Use a very strong magnet, a rare earth neodymium magnet.

This is the theory in principle. In practice, it is difficult to generate any useful amount of electrical power.



Reference: https://oceans582.wordpress.com/2013/05/17/generator-theory/

You will need a very sensitive analog meter to observe the current which will be very weak, in tens of microamps.

My point is, even if you had the materials and wiring done correctly, the induced current could very well be too weak for you to detect with a ordinary DMM.

 

One additional suggestion, even after all these good comments, is that the asembly in post #1 looks like the rotor of a small DC permanent magnet motor. Those used to be used in many motorized toys, and so I suggest, since those motors will also work as generators simply by sinning the shaft, that you get one of those motors and disassemble it to see the details of the construction more clearly that can easily be explained here.
AND, that wire may possibly have a clear insulation on it. Not all copper wire is actually bare, it may have the crystal clear insulation.

 

I was thinking about that, but I was not able to drill a hole into the magnet

That was another reason I didn't go that route for you. Other than the very weak, vinyl magnetic material, like refrigerator magnets are made from, magnets are made from very hard brittle stuff. Any with a hole, the hole is put in before being magnetized.

I don't know if you will continue with magnetic experiments but here is a link to a good source of both magnets and information on them - https://www.kjmagnetics.com/

There is a type of alternator that can be made without putting a hole in the magnets though, it's called an "axial flux" generator. Though in reality they are alternators. The magnets mount on a moving disc and the coils are stationary.

 

That was another reason I didn't go that route for you. Other than the very weak, vinyl magnetic material, like refrigerator magnets are made from, magnets are made from very hard brittle stuff. Any with a hole, the hole is put in before being magnetized.

I don't know if you will continue with magnetic experiments but here is a link to a good source of both magnets and information on them - https://www.kjmagnetics.com/

There is a type of alternator that can be made without putting a hole in the magnets though, it's called an "axial flux" generator. Though in reality they are alternators. The magnets mount on a moving disc and the coils are stationary.

Also,look at the automotive alternators, with the coil between two pole pieces, that are then bent to alter the flux as they pas the stationary coils around the perimeter. I have considered changing one of those by replacing the coil with a big ceramic speaker magnet. It might even take a stack of 2 of the ring magnets, but that should work to some extent. It would not be simple to regulate, but not every application need good regulation.
AND, an option is to have a plastic piece around a steel shaft, with holes in the plastic to hold short bar magnets or those round ones with poles on the ends. Not as efficient but very simple to visualize.

 

Here's a video I did using a DC motor from a CD Player. The video talks about free energy, then goes on to explain that no matter what - there is some sort of energy being expended in order to generate energy. Or - that is to say - the conversion of one form of energy into another. In this video I convert the energy of my thumb spinning a wheel into a rotational energy, which is then converted into electrical energy. That electrical energy (DC electricity) lights only one of the LED's mounted on the motor. Why only one? Because when the motor is spun in one direction the DC is going through only one of the two LED's. When the motor is spun in the opposite direction the OTHER LED lights. That's because by reversing the directional spin of the motor you reverse the polarity of the generated electricity.

 

I have considered changing one of those by replacing the coil with a big ceramic speaker magnet.

That is a commonly done thing with people making wind mill generators and those making electric motors from alternators.

 

Now you know that it is easier to move the magnet than to move the coil.
Now comes the big question. How fast do you need to move the magnet?

The amount of electrical power generated depends on the strength of the magnet. Yes?

A stationary magnet generates no induced current.
The magnetic field needs to be changing. The current induced is a function of the rate of change of the magnetic field. The faster it changes, the higher the induced current in the coil.

Another experiment for you to try is to wind a circular coil on an empty toilet paper roll with very fine magnet wire. You need a very large number of turns, in the hundreds or even a thousand turns.

Move a magnet in and out of the centre of the coil as fast as you can.
Use a very strong magnet, a rare earth neodymium magnet.

This is the theory in principle. In practice, it is difficult to generate any useful amount of electrical power.

View attachment 256587

Reference: https://oceans582.wordpress.com/2013/05/17/generator-theory/

You will need a very sensitive analog meter to observe the current which will be very weak, in tens of microamps.

My point is, even if you had the materials and wiring done correctly, the induced current could very well be too weak for you to detect with a ordinary DMM.

very interesting relationship between magnetism and electricity, I will definitely try that!

 

One additional suggestion, even after all these good comments, is that the asembly in post #1 looks like the rotor of a small DC permanent magnet motor. Those used to be used in many motorized toys, and so I suggest, since those motors will also work as generators simply by sinning the shaft, that you get one of those motors and disassemble it to see the details of the construction more clearly that can easily be explained here.
AND, that wire may possibly have a clear insulation on it. Not all copper wire is actually bare, it may have the crystal clear insulation.

Very great hint, maybe it is because this is not the copper wire I used elsewhere, I actually got it from a small motor from a toy

 

That was another reason I didn't go that route for you. Other than the very weak, vinyl magnetic material, like refrigerator magnets are made from, magnets are made from very hard brittle stuff. Any with a hole, the hole is put in before being magnetized.

I don't know if you will continue with magnetic experiments but here is a link to a good source of both magnets and information on them - https://www.kjmagnetics.com/

There is a type of alternator that can be made without putting a hole in the magnets though, it's called an "axial flux" generator. Though in reality they are alternators. The magnets mount on a moving disc and the coils are stationary.

I will definitely spend more time on magnetism, I am currently working on DC and got ahead of myself working with magnets there. I wanted to build a generator but could not find anything easy without the magnets

 

Here's a video I did using a DC motor from a CD Player. The video talks about free energy, then goes on to explain that no matter what - there is some sort of energy being expended in order to generate energy. Or - that is to say - the conversion of one form of energy into another. In this video I convert the energy of my thumb spinning a wheel into a rotational energy, which is then converted into electrical energy. That electrical energy (DC electricity) lights only one of the LED's mounted on the motor. Why only one? Because when the motor is spun in one direction the DC is going through only one of the two LED's. When the motor is spun in the opposite direction the OTHER LED lights. That's because by reversing the directional spin of the motor you reverse the polarity of the generated electricity.

That was my plan here. I wanted to generate "free" electricity and get a feeling of how a generator works. Nice video by the way, especially explaining it by means of energy. Where did you get all the parts from. Build it? Bought it?

 

The cheap hand operated flashlights contain about the cheapest possible generator arrangements, and are good examples of what can be done when minimum cost is the primary requirement. They also serve as examples of how loose tolerances can be and still have a product sort of work.

 

Where did you get all the parts from. Build it? Bought it?

Scrapped it. Came from an old stereo that had issues. The motor and gears are out of a CD player. It's the motor that moved the head back and forth to track the file it was playing. The two LED's are leftovers from another project. Soldering one on in one polarity meant you had to spin the motor in a given direction to light that LED. Adding a second in the opposite polarity meant you could spin the motor either way and one of them would light. I chose white and green LED's at random. They are "Super Bright LED's".

The normal means of wiring an LED is to start with knowing the forward voltage of an LED, then subtract that voltage from a voltage source. That gives you the amount of voltage you need to waste via a resistor. You use the data sheet (if you have one) and decide what current you want to push through the LED. In the case of my super bright's a good amperage is 15mA (milli-amps - or 0.015 amps). Divide the voltage attained from subtracting the forward voltage from the starting voltage by the amperage desired and you arrive at a resistance. Since the motor I used can barely generate 15mA when spun fairly hard I didn't need a resistor. It's intended voltage was 5V. Close to the approximately 3Vf the LED's. And though I haven't measured the motor's voltage output when spun by hand, nor have I measured the resistance of the motor windings; all I can say is the combination results in a usable demonstration as shown in the video.

Hope you learned something. I know my description may be hard to follow, but if you need further clarification I can give you some examples. Either start a new thread or message me directly. Keep in mind I'm pretty much a beginner level electronics guy. The advanced stuff I never learned. Has a lot to do with my limited math skills. If you're young and still in school, focus on your math. As an engineer it will mean the difference between being a good and successful engineer or being someone who thinks you can get free energy for free.

As I said in the video - there is no such thing as "Free" energy. It can only be converted from one form to another. In the case of the video I'm converting physical energy - the energy generated by my muscle spinning the motor - into mechanical energy, the spinning of the motor, which is then converted into electrical energy, then Light energy via the LED's. Nothing is free. Work must be done to accomplish work. Without it you have no work done - you have no energy.

[edit]
Muscle energy is converted into
Mechanical energy, which is converted into
Electrical energy, which is converted into
Light energy which is produced via the LED's.

You start with one form of energy and convert it into other forms. And during each conversion there is energy lost as friction and heat. That's the reason why you can't get "Free" energy for free. Solar energy is a form of free energy BUT it comes from another source of energy - the sun. Wind energy comes from wind, which is solar energy converted into heat energy which is converted into air movement (wind). Whether you use solar panels or a wind generator, you're converting energy from one from to another.

 

you're converting energy from one from to another.

Yes - converting it. Not creating it.

 

I thought that the original intent was to learn about electricity and magnetism, not to produce free electrical power. While experimenting can be a lot of fun, there are also hundreds of texts available that cover the knowledge and can even provide good insight and understanding. And not a single one of them on yootoob. (I do not like that entity)

 

That was my plan here. I wanted to generate "free" electricity and get a feeling of how a generator works. Nice video by the way, especially explaining it by means of energy. Where did you get all the parts from. Build it? Bought it?

I thought that the original intent was to learn about electricity and magnetism, not to produce free electrical power. While experimenting can be a lot of fun, there are also hundreds of texts available that cover the knowledge and can even provide good insight and understanding. And not a single one of them on yootoob. (I do not like that entity)

I think the comment about wanting to generate "free" electricity may have been mis-stated. Perhaps the TS is wanting to generate electricity by spinning a rotor within a magnetic field, which is what the video by @Tonyr1084 showed. However, if this IS an attempt at "Free" energy - as has been shown, there is no such thing. Not outside of converting one form of energy into another. Solar, wind, hydro, even a thermopile all can convert one form of energy into electricity. So perhaps @Thrm may want to revise his intent. Learning is always a good thing. Attempting to do the physically impossible is another. Until we find a way to negate the natural laws of physics we can not create energy. Nor can we destroy it.

 

I must confess, I thought the intention was to make free energy. If I'm wrong - my video still stands as an example of changing the form of energy from one sort to another. Just a side note - if the motor bearings were perfect and there were no load on it as if it were a generator then in theory you could spin it once and it would spin forever. We know it won't because of the friction of the bearings and the wind resistance inside the armature spinning around. But if we were to overcome THAT part then there's still the losses caused by the resistance of the wires. But suppose we eliminate that; then you are converting that energy into light energy via the LED's. As light is emitted and scattered into the ether the motor will draw down and the energy that was put into spinning it would be consumed.

I knew a guard at a prison who wanted to build a space station. Ambitious, I know. One problem he wanted to do was to remove excess heat from inside the station. His solution was a thermopile that would convert heat into electricity, channel that electricity to exterior lights and thus radiate that heat energy converted into light energy out into space. I suppose it would be a good working theory, but the size and efficiency of such a thermopile would probably make launching such a thing into space a non-starter.