alt.energy.homepower

Jim wrote:


>>You are illustrating that you've completely misunderstood what it's about.
>
>
> That's why the thread is titled stupid question. I confess I know not
> what this is all about. I am not an EE, that's my baby bruddah.

If I may try my hand at explaining this.

Voltage is pressure. Think push.

Amperage is flow (current). Think mass in motion for this simplistic
analogy.

You're the voltage.

Your push your very heavy automobile (the electrons) to move it a few
feet. This motion is current or amperage.

You gradually increase your pressure over time to your max push.

As the car starts to move, you gradually decrease the amount of push.

The car continues to move.

You decrease your push to zero, and then instantaneously run around to
the other end of the car.

You gradually increase your push to your max push. The car continues
in the wrong direction but is slowing down from your push, and it
eventually reverses direction also. The motion of the car is your
current and it is lagging your push (voltage).

Continue this repeating process.


Now repeat this process with a shopping cart.

The motion of the cart will not be lagging as much as the car was.

The volts (push) and current (electrons in motion) are more out of
phase with the car than the cart.

Maximum push, minimum motion. Minimum push, maximum motion.

The power factor corrections are to make the load seem more like the
cart than the car.

In other words, power factor correction makes the motion more
synchronous with the push.


When a voltage is put across a coil, it attempts to push electrons
through the coil. As the electrons move, they create an expanding
magnetic field. This expanding magnetic field induces a voltage
internal to the coil counteracting the external voltage applied to the
coil. This is called back emf. (Electro magnetic force)

Think of blowing up a balloon. As the springy rubber stretches it
stores energy and pushes opposite the pressure you are using to blow
up the balloon.

As the magnetic field grows in the coil, it stores the push energy and
pushes opposite the pressure you are using to expand it.

Remove the external voltage on the coil and the field collapses.

Since the collapsing field in the coil is reverse of the expanding
field that you had when you applied the external voltage, the internal
induced voltage is now reversed and it is now pushing the same
direction that the external voltage was.

In other words, a coil wants to keep the current the same. If it's
zero and you increase voltage, the coil attempts to maintain the lower
or zero current. Eventually the current will increase to match the
voltage.

If the current is at some non zero flow and you decrease the voltage,
the coil will supply the push to keep the current at the flow it has.
This is the energy that was stored in expanding the magnetic field.

Hope this helps.