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Re: NEON- Re: Power factor & Load Current

As always, excellent lesson here Telford,

I'll add the following images as an aid.  Once again I'll use water as 
an imperfect analogy.

Capacitor charging:  A pipe is connected to the center bottom of an enclosed 
container. A water meter is inline on the pipe. Water is fed from a pump.
As the container fills, we see a large reading of water flow 
(current) in the pipe.  

Once the container fills, there is an equilibrium that may be reached 
based on the power of the pump, the strength of the container, etc. 
For practical purposes, let's say that we reach this point where current 
no longer flows.  At the bottom of this tank we also have a small 
pipe going to a pressure meter.  When the container is first filling, 
the pressure (voltage) is low.  When the tank is filled the pressure  is much 
higher.

Capacitor holding a charge:  Close a valve in the pipe.  This is the 
equivalent of removing the capacitor from it's supply and ground.
Current flow is zero but pressure reading is still at maximum.

Capacitor discharging:  Remove the pump and open the valve. We'll 
call gravitiy's action here equivalent to a short circuit across the 
capacitor's leads.  The rush of water downward as it is discharged is 
measured as a large current.  The pressure reading in the tank 
proceeds to decline.

Anyone get wet?

Okay. The Inductor is trickier so bear with me.

My best image here is a flywheel.  Here I compare current to the 
flywheel's mass and rate of rotation. Voltage can be compared with the 
force needed to move or keep the wheel in motion.  At first where 
there is no motion in the wheel, it takes a large force to move it.
When the wheel is steadily flowing, very little force is needed to keep 
it in motion. If we wanted to stop or change the wheel's direction, 
even more force than before is now needed.  

The force that we are working to overcome is the stored energy 
of the moving wheel.


My apologies if this has made you all dizzy.  :-)


Kenny



 
> Like the capacitor, the inductor stores energy (as a magnetic field
> in it's steel core).  The amount of energy stored is a function of
> the current passing through it and the number of turns of wire wound
> around it's core, among other things.  The important thing is this:
> 
>         An inductor only has a voltage across it when we CHANGE the
>         current
> flowing through it.  The faster we change the current, the higher
> the voltage will be.  As long as the current remains steady, the
> voltage across it is ZERO.
> 
> So, capacitors and inductors are kind of like the yin and yang of
> the electrical world - very Zen.
> 
> End of part 1.  Part 2 tomorrow.
> 
> Regards,
> 
> Telford Dorr
> 
> 
> 
> 
> 
> 
> 
> 
Kenny Greenberg --  Neon - Scenic and Environmental Art  
                    Internet Site Consultant and Author   
KRYPTON NEON 34-43 Vernon Blvd Long Island City, NY 11106
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