In am Electrical Generator, where do the Electrons come from?

Ivan Seeking

Boy, my answer on this one really sucked.

As Integral stated, the generator acts like an electron pump that moves the electrons along the circuit. All that is needed is a complete circuit or a capacitive reservoir to store the charge. In the case of an isolated generator running a load, the current is circulating in a closed loop, so this is like taking a water pump and connecting the discharge to the suction side; presumably with some kind of load in between such as an orifice in the case of a water pump, or a resistor in an electrical circuit. Valence electrons in the conductors - the circuit - is the source of the charge.

scott1

Here's a diagram of what everone is saying. It's simple circut with a battery but it's the same effect as a generator. Bascially when the electorns go though the light bulb they lose energy form the energy conversion then they go back to the - side of the battery and get more energy form the battery. This will contuine until things 1) the battery dies 2) you noticed how there's a wire going back to the battery form the lightbulb if that wire gets disconnected there will be no constant supply of electorns to pump the energy into the light bulb.

Attached Thumbnails

 

triden

I always like to explain the ping-pong ball analogy with a pipe filled with water. When you turn on the 'switch' it's like putting a drop of water in one end of a water filled pipe. On the other end, out comes a drop, but overall the water in the pipe didn't really move. This can be applied to drift velocity because when the electricity flows through the wires, it isn't travelling like a car on a road....it's just "bumping other electrons down the line up a notch".

russ_watters

That just plain isn't how electricity works. A charged battery does not have more electrons in it than a discharged battery. There is no loss of electrons in an electric circuit.

Also, please reread the PF guidelines - this is not a place for indulging your own speculation, this is a place for learning real science.

Proton Soup

there's plenty of "external force" here, the chemical reaction going on inside the battery. you can think of this like a flame if you wish, since a flame is just a chemical reaction and the heat it produces.

batteries simply do not have excess charge. if they did, like batteries would repel each other, and you would notice because electrostatic forces are very strong. but there is not excess charge and no repulsion or attraction.