# Motor connected to battery won't run?

I have tried for hours (Yes, I'm obviously a beginner) to get a motor to run. I have taken a small hobby motor, attached a wire to one of the terminals, and attached two wires to that wire, connecting to to a battery. When it's connected, nothing happens.

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frollard5 years ago
Others have already answered it but one fundamental you must get when hooking up anything electronic is the understanding of electricity.

Electricity is quite literally the flow of electrons, through conductors. Electricity is cool because it can perform WORK by taking energy from one place and dropping it off in another. (in this case, from a battery/chemical reaction, and converting it to a magnetic field that turns the motor).

Electrons are negatively charged and repel one another, they are drawn to anything that is 'less' electrically negative than them. In a battery the chemical reaction physically pushes electrons at the atomic level from the positive terminal, through the battery, into the negative terminal. This makes the negative terminal have a negative charge. Those excess electrons in the negative terminal will be happy to go back to the positive side, but only via a CIRCUIT.
They have to leave the battery, go through a load, and return to the other terminal on the battery.

If you connect wires directly from one terminal to the other, the electrons will go straight from one to the other, with very little resistance, and that will cause the wire to heat up. this is called a short circuit.
5 years ago
Electricity is NOT the flow of electrons, except in metals.....In fact, its not "the flow of electrons" - since they move at less than walking pace.

Steve
5 years ago
They could be "flowing very slowly" - OK energy transfer.
5 years ago
But the energy flows at close to the speed of light, or at least a significant fraction of it. And in AC, the electrons wobble about a bit, but don't "flow"

Steve
5 years ago
Agreed, extremely oversimplified description that is not helpful for the future engineer, but good as a starting point. The inclusion of other charges moving about, ions etc, makes for a more complete picture.
5 years ago
You still have to explain AC.....
5 years ago
that's in next week's lesson :D
5 years ago
He he.

I think there is a great argument for getting the basics on solid grounds, and not having the lies-we-tell-to-children thing where one edifice of knowledge is torn down and rebuilt at each level.

Steve
5 years ago
Agreed again; Only problem then is that while many of us as children had the capacity for understanding/absorbing complex topics without stepping-stone packets that don't tell the whole truth - most people can't.

One must strike a careful balance between understandability and not being too tangential from fact.
Like explaining 4th dimensional math like a klein bottle without explaining a mobius strip, Asking someone with no knowledge of sides and edges to explain an object that visually does, but mathematically doesn't actually intersect itself is very difficult.
5 years ago
But you have broken understandability for anything but the most incorrect understanding, and for those taking it further stuff has to be UNlearned.

Case in point: Why do we use AC ?
This is the explanation usually given. Its "natural"

Its also complete cobblers.

Steve
5 years ago
My understanding is that it's most efficient to generate and use without conversion, and the first mass generation of electricity was mechanical, giving the sine wave we know and love.

3 phase improves on that by providing the benefits of AC with high current delivery throughout the overlapping waveforms.
5 years ago
and the first mass generation of electricity was mechanical, giving the sine wave we know and love.

Continuing our Socratic dialogue, why does mechanical generation make sine waves ?
5 years ago
the rotary relative moment of a magnetic field in the presence of a coil, generally provided by a permanent magnet, but often a self-exciting secondary coil.
5 years ago
NO ! Gotcha.
Now consider the effect of a current flowing in the armature/
Steve
5 years ago
to clarify, the movement of a conductor in a magnetic field. A coil is a series of the same conductor to amplify the voltage. The most efficient way we found was to rotate a coil or magnet, and the sine wave is representative of the relative motion between the two.
5 years ago
Nope. Its a VERY inefficient method to generate a sine wave that way..

I know you've read the lies told to children, and you'll ALWAYS see the "we rotate a coil in a magnetic field and we get a sine wave" crap.

But what happens when there is a load on the wires from the armature ?

This is entirely my point. The lies have obscured the reality so badly you can't see it. This applies to SO much electrical and electrronic theory.

Steve
5 years ago
Mmmm I used to have this conversation with the science lot at school. Yes I know the quantum vs Newtonian models. BUT as far as practicality is concerned as long as you have a mental model which fits the practicalities and you can use that model to help understand what is happening then which model you follow isn't really an issue.

As I can't see electrons, (and I have a weird opinion that they are green and hairy), how they do what the appear to do isn't a problems for me.

So lots of tiny balls filling up the conductor or capacitor etc arranged so that when you push one in the end another falls out of the other end immediately - of course it takes time for the one you just pushed in to get to the other end so the actual balls move quite slowly although their effect is more or less instant iIs OK for my mental model.

As far as I understand there is considerable doubt as to the reality of what electrons "are" if I can use such a loose term.

In quantum theory

- 'proven' mathematically and now in some degree practically -

every electron in the universe is interconnected with every other electron because no two electrons can exist at the same energy level. That being the case every time you warm something up or turn on an electric circuit you re-arrange the energy levels of EVERY electron in the universe!

I can write that, but find it hugely difficult not to scream HOW CAN THAT HAPPEN! :-)
5 years ago
I think tying "electricity" up with fields and not charge carriers very early is actually better for understanding than a system that still teaches that electrons are little balls orbiting in fixed shells around another group of fixed balls - a view that's been obsolete for 100 years.

Steve
Higgs Boson5 years ago
connect one wire to one terminal and the negative end of the battery, and connect another wire to the other terminal of the motor, and connect that to the positive end of the battery. If that doesn't work then you have a dead battery, a broken motor, or both.
rickharris5 years ago
Attached a wire to ONE of the terminals then connected two wires to that wire connecting to a battery....

OK You need 2 connections to the motor one to EACH terminal - One goes to the positive + terminal on the battery and one to the negative - terminal.

A 9 volt battery isn't the best for this you should try a single cell a C or D sized cell should work with a small motor. Use the top and bottom of the battery as the connecting terminals.
lemonie5 years ago
Put both the 9V battery-terminals on your tongue simultaniously; does that hurt?

L
The Skinnerz5 years ago
Do the wires form a Y shape, with both terminals of the battery joined together, and only one terminal of the motor connected? If so, the electricity coming out of one side of the battery is just going back into the other end, and not going through the motor.

Electricity will only flow through a closed loop, so you need two wires. One goes from one terminal of the battery to one terminal on the motor. The other joins the second terminal of the motor to the other end of the battery. This way the electricity flows out of the battery, through the motor, and back into the battery, making a loop.