Need expert advise! silly questions in DC generator :)

[Samjaotea]

Hi,

I'm not an expert in DC generator or dynamo, but let say some how I use a 12V normal electric DC motor and hook it to 12V DC power supply and make it spin!
Now question is:

if I connect the shaft of motor to 2 x DC Dynamo generator (not two motor please pay attention), let say in here 2 x 12V DC Dynamo generator.
does it means that I get 2 x 12V output only by supply 1 x 12V output!

I know it's not possible, but need a kind of explanatory, to be honest I google some pages and I'm aware I might be able to get 2 x 12V output but not the same AMP and if it's correct why is like that? where the energy goes.

Cheers
Sam

 

[waross]

Voltage alone is not energy.
With DC, energy is determined by Volts times Amperes. (With AC there are some other factors.)
Just as dry cells may be connected in series to increase the voltage, generators may be connected in series.
Your rate of energy in may be quantified by Volts x Amps in = (Volts x Amps out plus Losses).
Motors driving generators are quite common. They are called Motor-Generator sets or MG sets.
They are used to convert one voltage to another, to convert AC to DC, to convert DC to AC, to convert from one frequency to another and probably a few other uses.
Back in the days of vacuum tube electronics, a radio transmitter needed enough energy at several hundred volts to power the plate circuits.
They used a device called a dynamotor.
If you go back to basic principles, you will see that three factors determine the voltage of a dynamo;
The effective number of turns on the armature, the strength of the magnetic field and and the speed of rotation.
A dynamotor was basically a DC motor, often 12 Volts. The slots on the armature would be larger than normal. A second winding with many more turns per pole would be wound in the same slots and connected to a second commutator on the other end of the shaft.
Now when the motor was energized, the second winding would be moving at the same speed in the same magnetic field.
If the dynamo winding had 25 times as many effective turns as the motor winding the dynamotor would develop 300 Volts out from 12 Volts in.
To respect the law of conservation of energy, the Amps in must be over 25 times the Amps out.
Another option may be to use a belt drive between the motor and the generator. Subject to other limitations such as centrifugal forces, if the dynamo is spun at twice the speed with a 2:1 drive ratio the theoretical voltage will be twice as much.
Remember, Amps x Volts IN = (Amps x Volts OUT plus LOSSES)
A stray thought on the law of conservation of energy:
Breaking many laws often results in a penalty of some sort.
Anyone successfully breaking the law of conservation of energy may be richly rewarded. grin


Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[Samjaotea]

Hi Bill,

Many thanks, it was a kind of rich reply with every line full of information that I should read a book or google some to find out more about some

it looks like you give the reply in your last line:
Anyone successfully breaking the law of conservation of energy may be richly rewarded. grin

I do say you really smart and intelligent, because you somehow find out what was in my mind ,,,, now do you mean it's not possible???!!!

consider "Volts x Amps in = (Volts x Amps out plus Losses)" do you mean when my DC motor spin because on both side shaft connected to 2 x DC dynamo it needs more amp or the magnetic field of DC motor effect the DC generator?

in real life you see DC motor turn & turn and no matter what does connect to shaft! a fan blade or toothbrush lol so why not in reality we could not do such a things and use gearbox and other things to even change the speed?

Thanks

 

[itsmoked]

You will NEVER violate the conservation of energy law. No system of any kind will EVER provide more energy than what you put into it. That includes even something as simple as a one inch single piece of wire. The energy you feed into one end will always be more than what you can get out of the other end of it. So when you expand this into rotating things that have dragging bearings, cause the air to move around, and included hundreds of feet of wire, then you will always end up with less than you put in.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Skogsgurra]

In short: What you and thousands of other guys have been hoping for is not possible. And it will never be. There are words that describe over-unity aficionados. I am not going to use them. It wouldn't be nice to do so.

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.