AC motor questions

[forest]

I have a couple of questions about AC motors and not only. Please do not say it's off topic here, because I'm a noob in electronics.

I think that questions are important and we ALL should rethink the answers.

This topic is continuation of my investigations (as a noob) moved here from 'Infinity coil' topic.
You will soon see however that it's related to all topics in this section.

First : I learned that we have rotating magnetic field in 2 phase AC motor. Wonderful! Could it be
the same magic like in Hubbard coil, TPU ring, Hendershot motor,Searl generator and many others ?

Second : Seems unrelated but may influence our investigations I think. I talked with my friend who is a good electrician (and a patient man)  about two currents of the same frequency.
The questions are :
1. Can we put two AC exactly of the same frequency and in phase through the same conductor ?
2. Can we put two AC of the same frequency but shifted in phase through the same conductor ?

He told me that 1 is impossible but 2 is possible and very common ? Is that true ?

[forest]

Seems that nobody is interested. I would explain my idea.
If we could put more then one current of the same frequency but shifted in phase into electric circuit, then next question in chain  is as follows :

do we have each current separately and can extract each of two and use it's power ? I think the answer is yes.
two currents (each representing a part of electric power) flowing in circuit but each of them is separate.
but can we join them to sum their power ?
normally we can't because of phase difference, the current in one is small when the other is big and so on, the result is a mixed  mess something like noise or average power cut.

Apparently we have no hope, and even we will work out how to shift phases again what it would do for us ? Somebody will say : not much . I disagree...

Think a moment please and support my conclusions with open mind and knowledge I'm lack of.

[Charlie_V]

First : I learned that we have rotating magnetic field in 2 phase AC motor. Wonderful! Could it be
the same magic like in Hubbard coil, TPU ring, Hendershot motor,Searl generator and many others ?

I don't follow any of these motors so I couldn't help you in the comparison. However, I know a little bit about motors in general.  A rotating magnetic field means you have coils lined in a circle with one pole facing inward and you are energizing each coil in a particular pattern in time.  For a 2 phase motor then there are 2 different groups of coils being alternated on/off.  While one group is on, the other is off.  For a 3 phase or 4 phase etc. the groups are turned off and on with on/off times slightly overlapping the next group.  This is the rotating magnetic field they are talking about - its not magic at all. 

Second : Seems unrelated but may influence our investigations I think. I talked with my friend who is a good electrician (and a patient man)  about two currents of the same frequency.
The questions are :
1. Can we put two AC exactly of the same frequency and in phase through the same conductor ?
2. Can we put two AC of the same frequency but shifted in phase through the same conductor ?

He told me that 1 is impossible but 2 is possible and very common ? Is that true ?

Your friend is wrong, you can do both.  In the first case, the two AC frequencies will add and the voltages/currents along the conductor will be larger.  In the second case, the voltages along the conductor will be decreased depending on the phase difference.  At 180 degrees, the voltages/currents along the conductor will be canceled. 

To do either, a simple experiment is to get a 2 function generators, a long piece of wire and an oscilloscope.  Connect the positive terminals of each function generator to one end of the long wire, connect the oscilloscope to the other end - you can either ground the o-scope and function gens together or leave them floating, it doesn't matter (although floating you'll pick up 60Hz).  Starting out by keeping only one function generator on, the other off.  Start changing the frequency until you get maximum voltage at the end where the oscilloscope is - record that frequency.  Turn the other function generator on and set it to that frequency.  Then adjust the phase of one of the function generators (the expensive function generators have a phase option).  You'll notice that the voltage maximum read by the oscilloscope can be made larger (when the two are in phase) and smaller (when the two are out of phase).  You may also see, depending on how close you can get the function generator frequencies to match), a slight beat frequency.  Although the closer the 2 f-gens are to one another, the slower the beat will be. 

You'll need either a very long wire or high frequency func. gens.  For 3 meters (~9feet) of wire you should see a maximum voltage at the other end around 25MHz.  Although it will probably be much lower than that because of the added impedance of the oscilloscope and the low inductance of the single wire.  The voltage at the end of the wire will be close to 2 times the input voltage - you will be making an electrical standing wave on the wire.  Therefore, with both function generators going together and IN PHASE, both inputting 1 volt peak to peak, the output should be near 4 volts peak to peak as read by the o-scope. 

If you coil your long wire around a plastic tube, and keep a little space between each turn, the output will no longer be 2 times the input voltage but many more times - you'll have to adjust the frequency a little to get the maximum voltage seen by the o-scope of course.  This is because you'll be turning your coil into a resonant cavity.  This means that the AC waves entering the coil get reflected back and forth within the coil (unlike the uncoiled wire where they reflect from the end only once).  So as the AC wave train enters the coil, they add to the next.  In a sense you are using 1 AC wave, trapping it within the coil, and allowing it to add to itself over and over.  If you inject another AC wave, it will do the same and the phase of second AC wave will either add or cancel the like before. 

Hope that helps,
Charlie

[nueview]

what you are asking here seems to be a point not often discussed. logic and practicle experience so here is 35 years of practicle experience of what i know.

most DC resistive circuit components do not show a large current rise upon connection to a voltage source emf (voltage) and mmf (current) seem to move as a steady state of affairs coming to some balance and conclusion to flow were heat is generated as units according to the volume moving and its resistance to mmf. and i assume mmf and emf as wave theory present only minor external effects due to short strait runs of the circuit and capacitors seem to charge along a logrithmic ratio all these appear correct except inductors they seem to slow current in relation to field growth and then find steady flow as influence stabilizes.

In AC circuits most of the components react the same as if they were still in a DC circuit but here inductors seem to have a magnified effect almost as if in the first instant an inductor sees only the wire resistance and then as the feild influence grows they appear to gain and drip off as if the resistance is pulled from the surrounding medium which is set in motion as faradays law would suggest.

this then would seem to go along tesla's line of thought for there being only transverse and logditudinal waves how many or much transverse wave energy would have to be generated to suppress one ampere of current flow through an adjacent inductor or wire. but this would be faradays law and lentz law in conjunction if only it didn't work this way there would be no electric at all. so be glad lentz law works as it does.

in motors the windings can move reducing there interaction producing speed and reducing there interaction allowing mor current to flow for a longer period of time making it more apparent how little resistance there is to current flow without its interaction to the stabilizing effect of voltage and current by there reactance.

as you are now so once i was and as i am hopefully you shall become.  It has taken me a long time to fight my way to the understanding i now have wish i hadn't fought it so hard.

i do enjoy answering your questions they really make me grow aware of the world i am in and my place in it. in thinking through my answers for you i seem to gain insite into things i have seen and they seem to become much clearer. i have not done this since my son died 5 years back.

here i will give you something to think about make a small stream fo water from a faucet place a magnet near it and notice any effects, then bring a charged peice of styrofoam cup near it and watch what happens.

if you can generate a good static charge put some sugar in a small pile on a sheet of aluminum and let the charge arc through the sugar and note what happens you may be supprized.

truly there are simple things to confound the wisdom of men.

[forest]

I don't follow any of these motors so I couldn't help you in the comparison. However, I know a little bit about motors in general.  A rotating magnetic field means you have coils lined in a circle with one pole facing inward and you are energizing each coil in a particular pattern in time.  For a 2 phase motor then there are 2 different groups of coils being alternated on/off.  While one group is on, the other is off.  For a 3 phase or 4 phase etc. the groups are turned off and on with on/off times slightly overlapping the next group.  This is the rotating magnetic field they are talking about - its not magic at all. 

Your friend is wrong, you can do both.  In the first case, the two AC frequencies will add and the voltages/currents along the conductor will be larger.  In the second case, the voltages along the conductor will be decreased depending on the phase difference.  At 180 degrees, the voltages/currents along the conductor will be canceled. 

To do either, a simple experiment is to get a 2 function generators, a long piece of wire and an oscilloscope.  Connect the positive terminals of each function generator to one end of the long wire, connect the oscilloscope to the other end - you can either ground the o-scope and function gens together or leave them floating, it doesn't matter (although floating you'll pick up 60Hz).  Starting out by keeping only one function generator on, the other off.  Start changing the frequency until you get maximum voltage at the end where the oscilloscope is - record that frequency.  Turn the other function generator on and set it to that frequency.  Then adjust the phase of one of the function generators (the expensive function generators have a phase option).  You'll notice that the voltage maximum read by the oscilloscope can be made larger (when the two are in phase) and smaller (when the two are out of phase).  You may also see, depending on how close you can get the function generator frequencies to match), a slight beat frequency.  Although the closer the 2 f-gens are to one another, the slower the beat will be. 

You'll need either a very long wire or high frequency func. gens.  For 3 meters (~9feet) of wire you should see a maximum voltage at the other end around 25MHz.  Although it will probably be much lower than that because of the added impedance of the oscilloscope and the low inductance of the single wire.  The voltage at the end of the wire will be close to 2 times the input voltage - you will be making an electrical standing wave on the wire.  Therefore, with both function generators going together and IN PHASE, both inputting 1 volt peak to peak, the output should be near 4 volts peak to peak as read by the o-scope. 

If you coil your long wire around a plastic tube, and keep a little space between each turn, the output will no longer be 2 times the input voltage but many more times - you'll have to adjust the frequency a little to get the maximum voltage seen by the o-scope of course.  This is because you'll be turning your coil into a resonant cavity.  This means that the AC waves entering the coil get reflected back and forth within the coil (unlike the uncoiled wire where they reflect from the end only once).  So as the AC wave train enters the coil, they add to the next.  In a sense you are using 1 AC wave, trapping it within the coil, and allowing it to add to itself over and over.  If you inject another AC wave, it will do the same and the phase of second AC wave will either add or cancel the like before. 

Hope that helps,
Charlie

Thank you. Is there any reason why we can't use two generators to sent then same frequency and phase currents into transformer and output from the transformer feed back as a replacement for one of those generators  ? That way one of the generators is needed only at start and such transformer will continuously output current of bigger and bigger voltage or amperage probably up to damage or core saturation .
Does it makes sense ?