Is a motor a generator?

Is a motor a generator?

Absolutely, a motor can be a generator and in the hand a generator is a motor.

Somebody may try out to build your own Wind Turbine for hobbies or so. You may experience this, you broke your old computer printer or wherever you can find out a stepper motor. Why was that? Because you need a generator first if you follow the below steps: 1. A generator 2. Blades 3. A mounting that keeps it turned into the wind 4 .A tower to get it up into the wind 5. Batteries and an electronic control system

Another fact shows that a motor is a generator anyway. Do you have an experience wire the UIrobot stepper motor driver to your stepper motor? How do you know your wiring is correct? An easy and interesting way to find it out is turning the shaft of your stepper motor, fast and faster, if the LED light of the stepper motor driver flashing that means your wiring is wonderful, if not there is problem there. I don't exactly know it's a universal method or not, but it's worked on the UIM stepper motor controller.

Actually, while a stepper motor will show "electricity being generated", from a wind-power standpoint, its actually not the best motor-turned-generator you could use.

For one, most steppers have enormous amounts of cogging to be overcome, which translates ultimately into lost energy. Secondly, one has to then figure out how to take the voltages generated from the windings, and turn them from n-phase AC signals (which may or may not look like a good sine wave!) to DC signals; if it were a single phase AC signal (of any shape) it would be easier, but because all steppers have multiple phases, to use one most efficiently as a generator (once again, discounting the cogging issue), one would want to use all phases of the motor to draw power from, and converting such phased AC signal into a DC signal won't be easy (or inexpensive).

There are better and cheaper options for wind power, anyhow. Probably the easiest and cheapest is to pick up an automobile alternator from the junk yard (preferably an AC-Delco unit without a voltage regulator). Such alternators are designed to charge 12 VDC batteries; bypassing the regulator allows you to insert your own proper charge controller - but even if you can't purchase (or modify) one so it doesn't have a regulator (many current model vehicles use regulators in the alternator that are "built in" and generally difficult to bypass - though it can be done if you have the tools and time), you can still use it as long as you can get it to rotate at the speed an engine during normal driving would spin it (several hundred or more RPM generally).

The next best form of a generator that can be had cheaply are certain single-phase AC motors. Depending on when they were last used, they will have a residual magnetic field left in the rotor, that, when spun, can feed back into the stator (cutting lines of force, etc) and generate electricity. If it doesn't work right away, sometimes you just run it as a motor briefly, then it will work again. Several sites on the internet detail how to turn such a motor into a generator, as well as how to properly turn the signal (which, when properly combined with the right wiring setup and a certain sized capacitor, will give you approximately 50-60 Hz single-phase AC) into a DC voltage for charging a battery bank.

There are tons of methods of converting motors to generators; of course a motor can be a generator, and a generator a motor - Michael Faraday proved this almost 200 years ago; this is EE101 (if that; one should have learned about Faraday by about age 11, IMHO). You can find tons of information on wind power and how to homebrew it on the internet as well as from tons of books (most written in the 1970s, actually, during the "earth day" and "oil embargo" years).

What is the point of this question anyhow, now that I have exhausted it enough? Is there something in this Arduino related (I suppose one could use an Arduino in a charge controller or phase convertor system)?

it can be ;).. perhaps it will be a little inefficient

Depends on what you mean by motor and what you mean by generator. In general any electrical motor has the basic components to be a generator but it may not be as simple as turning the shaft. Indeed most larger motors won't generate anything no matter how fast you spin their shaft until you excite them (electrically not hmmm in other ways) which may involve additional components /control gear. So if you want a more helpful answer state the type of motor and what you want it to do.

im not even going to reply, it might excite cr0sh and make him into a generator, man that much hot air could power a small city, does it matter if it’s Arduino related?

im not even going to reply, it might excite cr0sh and make him into a generator, man that much hot air could power a small city, does it matter if it's Arduino related?

At least I was able to give a reply that not only helped to answer the question, but perhaps could be used to learn to ask better questions in the future.

;)

im not even going to reply

I am, so how does one not reply in a reply :-?

Depends on the motors. Some motors can be used as generators others not.

Example of motor that can be used as generators: stepper motors. Example of motors that can not be used as generators: induction motors http://en.wikipedia.org/wiki/Induction_motor.

Anyway using a motor as a generator and vice versa usually comes with a loss of efficiency. Most engines are designed and optimized for their specific use.

Udo

Example of motors that can not be used as generators: induction motors http://en.wikipedia.org/wiki/Induction_motor.

Wrong:

http://www.qsl.net/ns8o/Induction_Generator.html

http://www.google.com/search?q=induction+motor+generator&ie=utf-8&oe=utf-8&aq=t&rls=com.ubuntu:en-US:official&client=firefox-a

I've got an old AC induction gearmotor I pulled from a copier out in my shop that works fine as a generator if you spin it; one the only reasons why I kept it - well, that, and it was one powerful gearmotor (and a strange story about how I managed to get the copier home after finding it out in the middle of the desert).

:)

OOps, I was not aware of that. Learned one new thing today, thanks :) However to be a little bit picky, if I undestand the article right you have to modify a little bit before it works. So my initial statement is not completely wrong?

Udo

However to be a little bit picky, if I undestand the article right you have to modify a little bit before it works. So my initial statement is not completely wrong?

I suppose if you consider adding running capacitors in parallel across the leads a modification, then perhaps “yes”?

However, some induction motors (with the exception of smaller shaded-pole motors, which work differently than a standard induction motor) already come with a running capacitor, but some don’t I suppose (it depends on how and where the motor is mounted, the cap is typically physically large, and may be mounted to a frame or something separate from the motor). You may also have to remove the starting cap (and/or change the switchover mechanism).

The induction motor I have had a small starting/running cap arrangement built into it (somewhere on it), but if I were to use it for power generation, I would likely replace these with something larger, just for safety.

As far as shaded pole motors are concerned, which are induction motors as well - I guess we should probably say that “some induction motors” can be converted to generators. Most of the induction motors in a house will be of the shaded-pole variety (small fans, as well as ceiling fans and the like), but other induction motors which do use starting/running capacitors can be found in places like a refrigerator (but this motor is built into the compressor, so not as easy to pull out for use as a generator) or an air-conditioner (generally 2 or 3 induction motors there).

I’ll give you this one, if you give me mine!

:wink:

Great, I give you yours :)

OK, so if I couple a motor to a generator and wire the generator's output to the motor's input I will get free power, right? Maybe I'll need a phasing cap in there somewhere. ;)

Lefty

so if I couple a motor to a generator and wire the generator's output to the motor's input I will get free power, right?

No they won't run fast enough, you will have to use some gears that increase the motor speed before it is transfers to the generator. However, any old gearing won't do. You have to use the sort that increase the torque.

Yeah, but once you have these gears you can cutout the fancy electrical stuff. Once started they can drive themselves :)

Udo

What if once they are started, you rotated the whole assembly really fast on a perpendicular axis? Would that increase or decrease the output?

I'd like to address the OP's original question (subject): No. A motor is a motor and a generator is a generator. While in many cases one can be used for the other purpose, they are not the same thing, spammer.

;) :P

OK, so if I couple a motor to a generator and wire the generator's output to the motor's input I will get free power, right? Maybe I'll need a phasing cap in there somewhere.

Lefty

I posted an explanation of exactly how to get this to work - my post seems to have been deleted. Big Oil must have gotten to the management of this forum >:( :-X

A motor is a motor and a generator is a generator. While in many cases one can be used for the other purpose, they are not the same thing,

I would disagree. A motor is something that turns electricity into mechanical movement, a generator is something that turns mechanical movement into electricity. While you can optimise designs to be better at one thing than another fundamentally the interaction of magnetic field and current being carried by a wire is a reciprocal interaction.