Author Topic: Circuit setups for pulse motors (Read 270030 times)

hoptoad · « **Reply #345 on:** February 10, 2008, 06:02:13 AM »

Quote from: Artic_Knight on February 10, 2008, 05:22:42 AM

i understand the principal of pulsing, its a known fact that even factory made electric motors suffer no noticable loss in performance if the electrical input is regulated in equal pulses of off and on. however i do not understand the back emf. i know what it is however how is it collected? is that what the outer coil is used for? and can the firing coil be set up with a diod to collect back emf? does collecting the back emf for use have an impact on the motors performance verses not using the back emf?

@Artic
You are correct that even factory made electric motors suffer no noticable loss in performance if the electrical input is regulated in equal pulses of off and on. Pulse Width Modulation is the preferred means of controlling all DC motors.

It may be tedious reading, but the answers to your questions might be on Pages 2+3 and Following Pages at this link below :

http://www.totallyamped.net/adams

Cheers from The Toad Who Hops

casman1969 · « **Reply #346 on:** February 10, 2008, 08:19:22 PM »

@ HopToad

Thanks for the link, it helps to clarify. I'm going through various common steel tubes to see which ones will work the best but as usual it will be trial and error. In the link, you said they work better as pickup coils and I do believe it but I'm more focussed on the drive aspect.
Can you suggest the optimum AWG wire size for drive coils if I'm using 2 X 1 X 1/2 N42 Neos?
Currently using 20AWG and have a single winding resistance of +/- 6 ohms and can adjust my input to approximately .1 amp. This arrangement gets me pretty good BEMF on second winding and I feed that serially to three more pickup coils giving me a FWB rectified 49V which I'm pulsing (10K MFD cap) back while motor is between drive pulses. Damn thing will go figuratively forever with very little drop on battery. Yes I'm learning and yes I'm having a ball. Thanks for your research and good work.
I check up on this site every day (work does have a way of interfering!!!)
Thanks again,

Carl

bakercool · « **Reply #347 on:** February 10, 2008, 08:36:06 PM »

Hello All!

I'm almost done restoring my 59' Ford, and still waiting for a lot of the stuff I ordered to come in (like the rotor, etc). I'm hoping to start building my motor in about 2-4 weeks, depending on delivery.. EXCITING TIMES!!!!

I have been searching desperately to find a way to take a car battery, and reduce the voltage down to about 12v - 5amp (or less amps). I hooked up a potentiometers, but it just went POP! and that was the end of that.

Do I have to buy/make a circuit to reduce the amps coming from the battery? I thought I would only need a resistor, but the ones I bought just overheat real fast. Any help would be greatly appreciated!!!

Corey

Nastrand2000 · « **Reply #348 on:** February 11, 2008, 02:39:33 AM »

@bakercool,

The way I control current flow in my motors is by adding or decreasing resistance (with resistors) to my trigger coils. Hope that helps.
Jason

bakercool · « **Reply #349 on:** February 11, 2008, 03:01:46 AM »

@Nomen
I looked into the resistance in the coil, but want to run specific amounts of turns. Thanks for the input though!

@Jason,

Thanks! I tried some resistors, but they all overheat superfast. Is there like a resistor "number" I can get from you? I'm having a hard time figuring these things out.. I got a DC Converter so I can continue to test my Coils from 5-24 Volts, that should be cool... I need to get my amps down though.. Thanks Jay!

hoptoad · « **Reply #350 on:** February 11, 2008, 09:29:46 AM »

Quote from: casman1969 on February 10, 2008, 08:19:22 PM

I'm going through various common steel tubes to see which ones will work the best but as usual it will be trial and error. In the link, you said they work better as pickup coils and I do believe it but I'm more focussed on the drive aspect.

Can you suggest the optimum AWG wire size for drive coils if I'm using 2 X 1 X 1/2 N42 Neos?

Currently using 20AWG and have a single winding resistance of +/- 6 ohms and can adjust my input to approximately .1 amp.

@Casman

To see any real difference in operation with hollow cores, you need to compare apples with apples (hollow). By basing the outer dimensions of your hollow core, on the dimensions of a solid or laminated or air core that you're already using, a reasonable comparison of the differing properties of each core can be made.

Assuming your supply is 12 Volts, then "+/- 6 ohms" (is that six ohms) DC coils wound onto hollow cores of the same diameter and length of a solid core, should yield very good comparative results.

Hollow cores will have less inductive reactance than a solid core due to the lesser amount of core material, but a greater current consumption associated with less reactance should be offset by an increase in the rotor speed due to lower magnetic drag . This raises frequency and causes reactance to rise again. Its a game that pulse motors play

To increase impedance of a coil (on any core), you can (a).Wind more turns on your coil, (b) increase the diameter of the core (c) increase the length of your core, or (d) any combination of all three methods.

Make a coil based on what you already have, then learn and proceed from there. Then you can decide yourself how to redesign your coil to best utilize the positive benefits of a hollow core, and how best to solve the inadequacies of low impedance cores.

I am glad you are going to experiment with hollow cores. I hope you discover something that I haven't.
I don't want to steer you too much in any direction with hollow cores,I would rather let you find out whatever there is to find out by experimenting yourself, and reveal your results to all of us here, because an objective, untainted "fresh" opinion about them is welcome and needed....KneeDeep

Cheers from the Toad Who Hops

Ren · « **Reply #351 on:** February 11, 2008, 11:18:24 AM »

Baker I struggled to come to grips at first with controlling amp draw. Its not as simple as plugging a hole so less comes out. Then again maybe it is. You will need to build your circuit and test various resistances and configurations WITHIN the circuit to vary current draw. You simply cant place a choke on one end.

Well, you can, sort of. I see the coil as being similar to a choke. The thinner the wire and the more turns creates greater resistance (travel path) for the energy to flow. The pulsing aspect will also do this too as current is being switched on and off.

This is why I recommend a Bedini build for your first. Its so simple and schematics are everywhere. You will get results if you follow the instructions, and you will have something that works.

You will also have a better understanding of the components and general assembly of your motor which will allow you to move forward onto better things.

Artic_Knight · « **Reply #352 on:** February 11, 2008, 10:29:18 PM »

im very confused about back emf and cores now. from what i have read in this forum the best core is an air core, from what i read about the adams motor the best core is an iron core.

the Adams pulse motor uses a perm magnet and uses the pulse of electricity from batteries to positively attract the magnet, then when the magnet is within range, the current stops the magnetic field that was in the iron colapses and creates a reverse current that pushes away, so now for the same pulse of an air core your getting both the pull and push for same energy. a much better deal if it works.

however this group does not agree? has anyone tried this particular method?

and now there is 2 different descriptions of back emf, if they are the same please let me know, however now we have a reversal of the magnetic feild with or without the perm magnet to produce it. and it appears this reversal counters the attraction the magnet has on the iron and with enough force even repells!

does anyone have a good idea about these forces? if theres a website that is good too.

Artic_Knight · « **Reply #353 on:** February 12, 2008, 03:44:32 AM »

ok i found some websites but im still confused at the moment, maybe i can figure it out later.

the motor layout i have seen on one website uses iron core that is positively magnetized and the magnet is attracted to it, then the current stops and the magnet is pushed away from the magnetic field collapsing and reversing? but your talking about taking this back emf in the form of electricity and reusing it?

Ren · « **Reply #354 on:** February 12, 2008, 07:53:33 AM »

Artic I too get a little confused with all the "emf" terminology. Hoptoads page explains it well, but it still isnt quite clear in my head yet.

I see there being two ways to operate an "Adams style monopole motor" You can wire your coil to fire in attraction or repulsion. But if your clever you can benefit from both styles. My monopole fires just after dead center, repelling the magnet closest, but at the same time attracting the scalar south from the next magnet. So it kind of harnesses both attraction and repulsion. A break down of the SG bifilar monopole would be as such:

coil (off) with no magnet in the vicinity.
Magnet approaches coil (off) attracted to the iron core inducing voltage through both wires.
Trigger winding in turn uses the small amount of voltage induced to "fire" the power winding, completing a circuit momentarily around the iron core.
Coil(now on) magnetizes core and becomes an electromagnet of same polarity to rotor magnets.
Rotor magnet is push/pulled away and induced voltage dissipates from coil, shutting off circuit and collapsing magnetic field.
Collapse is collected and cycle repeats itself.

This isnt how all styles of pulse motors work but it is a basis for basic models. It can work slightly different in that the pulse attracts the rotor and switches off at the precise moment as to prevent the rotor hanging up in the magnetic field.

I like to see it like this. You can collect the collapse of the coil and other associated energies with the appropriate circuitry, of which most is covered at the totally amped page. How you chose to store and reuse that energy is up to you. There is plenty of different ways to trigger your circuits to fire and plenty of different ways to collect that which is normally wasted.

hoptoad · « **Reply #355 on:** February 12, 2008, 08:07:57 AM »

@Artic
quote ...
im very confused about back emf and cores now..........
and now there is 2 different descriptions of back emf, if they are the same please let me know..........

Its easy to be confused when common textbooks use the words back emf to describe two different phenomena. Yes, there are two different forms of back emf. To avoid confusion there are other names used to descibe the two forms.

1. Back EMF (Counter EMF) is normally only associated with an electric motor. It arises in opposition to the Applied EMF (your current source) when the motor is on and running.

This form of back emf occurs, because the rotor, as it turns, acts like a generator, but with opposite polarity to the applied voltage. If the back emf was equal to the applied emf, the motor would continually stall. But the beck emf is always less than the applied emf, so the motor will turn and continue to run. This is true of ALL motors.

2. Back EMF (Collapsing EMF). Also known commonly as "fly back". This can occur in any type of pulsing system, but only if there is inductance in the circuit.

This form of back emf is caused when the current which is flowing through the coil is suddenly turned off. The magnetic field of the coil collapses, and induces a voltage potential which is opposite in polarity to the original applied voltage. This potential can be transformed into usable power in the form of either electricity, mechanical torque, or a combination of both. Tapping this form of back emf for re use can be successfully achieved in numerous ways.

Cheers all

hoptoad · « **Reply #356 on:** February 12, 2008, 08:20:36 AM »

P.S. @All, in reference to my last post
Back EMF (1.) also known as Counter EMF is "Counter Productive"
Back EMF (2 ) also known as Collapsing EMF is "Collectible"
It also becomes less confusing if you apply the alternative names for each type of emf, all the time.

Cheers all

Artic_Knight · « **Reply #357 on:** February 13, 2008, 01:05:09 AM »

ok so this isnt going to change me proving it for myself but has anyone tried a positive attraction and with the collapsing magnetic field repulsion on the magnet to push it away?

seems to me if you positively attract a magnet first and then in dead center of the iron core stop the current it should stay on the iron core, of course unless its actually creating this reverse repelling force then it will drive the magnet away.

on a side note you will find a picture from the adams page, now according to the page if you connect A and B you will get the back emf. if the current is reversed then you need the negative pole or collector of the cap at A and the positive at the diod B and this is supposed to catch flyback but if it does then you dont need the diod, if it does catch the back emf it will also collect the battery power because nothing is blocking it, shouldnt the drive curcuit be between the powersource and A on the positive side? and for "flyforward" or normal current you connect B and C now the negative or collecter should be on C and the emmiter going to A if you do not want it reused right away and stored for another pulse right?

my understanding of the back emf is that the electric current reverses and by this diagram and some miricle i now think i understand how to collect it.

but the reversing of the magnetic fields... that doesnt sound right. mind you im not saying its not possible cause i have started to see many things in modern science that were not possible 6 years ago and now the very same people are going "look what i made!" funny, i could have told you back when it wasnt possible how to make it like a rail gun. just use powerful ac coils

any hoot thanks for being patient and assisting me with this!

hoptoad · « **Reply #358 on:** February 13, 2008, 06:42:50 AM »

@Artic

quote..... but the reversing of the magnetic fields... that doesnt sound right.....

When the applied coil current suddenly ceases, The magnetic field doesn't reverse, it collapses and induces an opposite voltage potential at the collector which is connected to point B via an output diode. When this potential is directed via the diode and a load (usually) back to point A, it forms a current loop within the coil, the diode and a load. The current flows in the same direction though the coil as the original applied current.

This causes the magnetic field to collapse slowly instead of immediately, as the recirculating current maintains a degree of magnetic strength for some time after the applied voltage and current has been turned off.

The + ve of the collapsing field voltage occurs at the collector and current goes from collector through diode to point B which is now a decoupled +ve with reference via a load to point A, (for fly back) and a higher value decoupled +ve (for fly forward) with reference via a load to point C. In both instances, the positive of a capacitor or battery load should be connected to point B as shown in fig 7 on page 3. on my site

In all instances, the current through the coil itself, will be in the same direction. (if you've wired it correctly)

The diode must be inserted between the collector and the load (in the circuit shown), or the load will simply be in parallel with the drive coil (fly back) or in parallel with the switch (fly forward). In both cases, without a diode to decouple the output, the result will be poor performance at best, or a blown transistor Mosfet switch at worst. Both no no's

Cheers from Hoptoad

Artic_Knight · « **Reply #359 on:** February 13, 2008, 09:11:05 PM »

for flyback:
so if you have a negative potential at point B and the diod is allowing flow in which direction? from the coil to point A? then the only flow i can see is the unused electricity or potential work still available in the curcuit to get resycled which you referr to flyforward. if its negative then the positive current or the direction its flowing is back at the + pole of the powersource the other direction? ive never heard of a negative value moving in the positive direction. i will try it dont get me wrong! but i just dont see it! my grandfather is a electronics inventor and based on his teachings which are partly text book part trial and error he has never heard of such a feat. it wont cost me anything to try since i will be using a breadboard i can just shuffle the curcuits around.
seems to me whith that kind of set up the cap would become charged from the powersource and never fire since the diod will not permit the reverse in direction.

this is baffleing but thank you for the time you have spent with me.

EDIT: wait i see what your saying! but im not sure if a "collapse" is the best way to describe it! ok so the electrical current is fed in from the - end to the + end of the coil this makes a magnetic flow that moves from - to + now when you stop feeding it the leftover magnetic current is funneled back into the coils going in the same direction from -to + so essentially the magnetic current is obsorbed back into the coils and if it was normally induced into them. ok! now there isnt a need for a cap since your going to route the current directly back into the coil to let the natural resistance of the coil wear it down slowly, so you connect via a wire piont B to point A right? the diod lets all positive current flow more directly back to the coil keeping its polarity for longer requiring a shorter pulse draw from the power sorce reducing AMPs. right? when everyone was talking about a collapse i was thinking the magnetic current reversed. but thats what i read on the origional adams motor! hmm, thats what doesnt make sense and thats where the confusion is coming from, how is this "collapse" reversing the magnetic flow and having power to "push" the magnet away? seems to me its just cutting off and letting the magnet fly right by!

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Author Topic: Circuit setups for pulse motors (Read 270030 times)

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