MH's ideal coil and voltage question

[picowatt]

Just a few thoughts:

1.  By stating that we are using an inductor of 5Hy, we have, by definition, stated that the inductor will produce a CEMF of 4 volts when the RATE OF CHANGE of the current flowing thru it is .8 amps per second.  Any inductor that does not produce 4 volts of CEMF when the RATE OF CHANGE of the current flowing thru it is .8 amps per second is not, by definition, a 5Hy inductor.

2.  When the 5Hy inductor is connected across the 4 volt Vsource, current flows until it reaches a rate of change of .8 amps per second at which time a CEMF of 4 volts is generated.  When the inductor's CEMF equals 4 volts, the rate of change of the current flow drops towards zero amps per second.  As the current flow's rate of change becomes less than .8 amps per second, the CEMF produced is also less than 4 volts.  When the CEMF produced is less than 4 volts, current flow will again increase until it once again reaches a rate of change of .8 amps per second, causing the CEMF to again be 4 volts, which again reduces the rate of change of the current flow toward zero.  This action continues for as long as the 4 volts is applied across the inductor. 

3.  Although the action above is described in a step wise fashion, those familiar with the use of negative feedback in analog circuits will easily visualize the above action as being a smooth, continuous, and self-regulating action that maintains a continuous .8 amps per second of rate of change thru the inductor. 

4.  Unlike a "normal" inductor, the magnitude of the current flowing thru an ideal inductor having zero DC resistance has no effect upon, that is, produces no deviation from, the as defined .8 amps per second rate of change necessary to generate 4 volts of CEMF (as evidenced by a linear increase in current).     

5.  With regard to a "normal" inductor that does have resistance, as the magnitude of the current flow changes, the IR related voltage drop produced by that current also changes.  That voltage drop does affect, that is, causes the rate of change to deviate from, the as defined .8 amps per second rate of change necessary to generate a CEMF of 4 volts (as evidenced by a deviation from a linear increase in current).

6.  Being more so an energy storage and retrieval mechanism, the reactance of an inductor is not a "dissipative" mechanism.  Only whereby the inductor deviates from ideal (having resistance, etc.) is any energy stored or retrieved lost to dissipative mechanisms.

PW

[minnie]

  tinman,
        how about measuring it? My guess is that you'd have to be quicker than C.
               John.

[tinman]

That graphic you made is cringe-worthy and nobody wants to touch it.  All that you are doing is showing is how foolish or ignorant or stupid you can be.  Like I told you, buy yourself a few books on basic electronics and lock yourself in a room for a month and read them and understand them.  You definitely deserve the trash talk in this case.

I dont care how you wish to word it MH,as i am not bound by incorrect definitions such as it seems the EE world is,nor am i too worried about what you think. When a value drops,to me it means it is now lees than the supply value. If you have a drop in HP from that that is supplied,then you have less than that of what the motor is putting out. We get a drop in HP from the engine to the wheels,due to friction in the drive line-so less out than in as far as HP go's.

The resistor causes no drop in voltage to that being supplied-if the supply can provide the required voltage. So,regardless if that resistor is across the battery or not,there is no drop in voltage-the voltage remains at 2 volts.

Brad

[tinman]

Just a few thoughts:

1.  By stating that we are using an inductor of 5Hy, we have, by definition, stated that the inductor will produce a CEMF of 4 volts when the RATE OF CHANGE of the current flowing thru it is .8 amps per second.  Any inductor that does not produce 4 volts of CEMF when the RATE OF CHANGE of the current flowing thru it is .8 amps per second is not, by definition, a 5Hy inductor.

2.  When the 5Hy inductor is connected across the 4 volt Vsource, current flows until it reaches a rate of change of .8 amps per second at which time a CEMF of 4 volts is generated.  When the inductor's CEMF equals 4 volts, the rate of change of the current flow drops towards zero amps per second.  As the current flow's rate of change becomes less than .8 amps per second, the CEMF produced is also less than 4 volts.  When the CEMF produced is less than 4 volts, current flow will again increase until it once again reaches a rate of change of .8 amps per second, causing the CEMF to again be 4 volts, which again reduces the rate of change of the current flow toward zero.  This action continues for as long as the 4 volts is applied across the inductor. 

3.  Although the action above is described in a step wise fashion, those familiar with the use of negative feedback in analog circuits will easily visualize the above action as being a smooth, continuous, and self-regulating action that maintains a continuous .8 amps per second of rate of change thru the inductor. 

4.  Unlike a "normal" inductor, the magnitude of the current flowing thru an ideal inductor having zero DC resistance has no effect upon, that is, produces no deviation from, the as defined .8 amps per second rate of change necessary to generate 4 volts of CEMF (as evidenced by a linear increase in current).     

5.  With regard to a "normal" inductor that does have resistance, as the magnitude of the current flow changes, the IR related voltage drop produced by that current also changes.  That voltage drop does affect, that is, causes the rate of change to deviate from, the as defined .8 amps per second rate of change necessary to generate a CEMF of 4 volts (as evidenced by a deviation from a linear increase in current).

6.  Being more so an energy storage and retrieval mechanism, the reactance of an inductor is not a "dissipative" mechanism.  Only whereby the inductor deviates from ideal (having resistance, etc.) is any energy stored or retrieved lost to dissipative mechanisms.

PW

PW

I guess that it could be looked at that way,but dose not resolve the fact that current still flows when there is no potential difference.

Also,why is this not true for a DC PM motor-such as the ones used in my video.
If the BackEMF is equal to the applied EMF,then the motor will not draw any current-or current will not flow through that motor. This i have-and can do again more accurately show on my bench.

BackEMF and CEMF are one in the same.
Inductive kickback is BackEMF. We are now saying that the inductive kickback from our ideal coil,will now give back the same amount of energy it took to create it,when the CEMF value is equal to the EMF value across that coil,as we have no I/R losses.

As far as i can work out,if the feedback is going to be the same as the applied,then the net power flowing is 0--we just end up with a tank circuit that keeps self oscillation.


Brad

[tinman]

Anyway,here is a quick and dirty test i did on the BackEMF value the magnets play a part in,in regards to a DC PM motor.

It was going to be a much more accurate test,but lack of the needed equipment means we only got a !round about! value-you will see why.

https://www.youtube.com/watch?v=-Jf_daUOdy0


Brad