Simple Motor

[Matthew Jones]

So we ended a small discussion on the motor generators thread. Starting new thread for all this.

IRon has replicated some older work and seems to have had pretty good results.
I have not worked on that project in a long time. Abandoned it some time ago.

I was going to go over the Tesla Motor at some point but the 2 projects have a lot in common so I can go over what I would do different if I did rebuild the project.

So over the years I have gathered a lot of tools that help me plan and help anticipate results. Also I have got pretty good handle on topologies of different solid state circuits like boost/buck converter. That particular motor is a boost converter. Not much of one but still a small step up.
I love this calculator:
https://www.daycounter.com/Calculato...lculator.phtml
So it kind self explanatory but I can fill in the blanks a bit. With the simple motor your trying to take 12 volt out of one battery, move the magnet across the coil and deposit the power in the inductor to the charge battery. With LA batts the voltage that hits the battery doesn't really matter because unless its ridiculously high the battery just absorbs it. But lithium's will catch on fire if they are charge with to high of voltage. And with both types the best way for long life and peak charge rates is to be just above the charging voltage. Maybe 2 volts above. So use the calculator and let it give you the answer....

Input: 12v
output: 14v
DVD: .4
TVD: .01
Freq: Number of magnets on rotor x RPM. guess about 2000. Or if you have rpms already use that value.
outCurrent: 5
minimum outC:0
Inductor ripple, Start with 20%
V ripple, start with .1 volt. Doesn't really matter

Now you have an outline. The biggest 2 things on it you need are duty and the size of L in my case I came up with 558.4 uh.
Now thats all well and good but what I have found in the past that coil (Or otherwise known as a solenoid) tends to be way more inductive. I have coils that 5 Henries when you measure them. But this where we can adjust calculator. Hit BACK on your browser and adjust the current ripple to 1. Now calculate and you'll see the inductor is a fair bit bigger. Mine came to 11 mH (+-)
Now we can plan a coil with this calculator:
http://hyperphysics.phy-astr.gsu.edu...ic/indsol.html and this chart https://www.solaris-shop.com/content...ze%20Table.pdf

So you have a spool but if not this will give an idea of what you need. There are 2.54 cm in an inch start with 200 turns and adjust. So now you can figure out your coil window. Remember more turns more induction and also in a spool the the core does not count in the width. So the coil radius is the size of the lip on the spool. Once you get the max area of your spool times that 80%. Thats your workable area. Now divide that workable area by the wire size Squared and you can get the max number of turns.
So if your max doesn't bring the induction up to the point you need it you need a bigger coil or in the original calculator you can adjust your ripple to make it work. So you have an idea of what's going on.

All in all this process should make the recovery more efficient. Your not hitting with high voltage and letting them dissipate it.

1 more thing is the Duty cycle. You will have to stick with duty the that calculator gave you. Depending on what drives you switching will have to fire at that amount of time. You can consider the space between the end of one magnet to end of the next 100% duty. In the case based on our earlier numbers we are going to fire 14.9 percent of the time probably when the coil is in front of the magnet or there about. Best to have adjustment to advance your timing.

So we can keep talking about this as needed happy to answer any questions you have. While I have time I am building the TS motor. I'll get some highlights and post the results here.

Matt

[i_ron]

Thanks Matt for starting a new thread. Where we over lap here is my use of your fly back scheme.

Well I have built my share of Adams Motors in my day but never with the success claimed. The last one was carefully modeled on Patrick Kelley's design but again no success. One of Aaron's presenters came up with some ideas.
https://waveguide.blog/pulse-motor-g...onsiderations/

What I gleaned from this was use a higher voltage. Nick Kraakman says 48 volts is a minimum.

Now what ties our motors together is the use of both poles. I have run into this before, Tinman, Bedini et al, So I did a test mock up using both poles and the only secret is it must have a flux return path. It is sort of counter intuitive one pole so much attract in --- two pole twice as much pull in, right? Well not so there is four times as much pull in.I am not sure where you triggered yours but I have stuck to the Adam's principle and the main driving force is the attract in, then at TDC the coil is fired with just enough strength to let the core depart from the magnet unhindered. Thus the trigger pulse must be long enough to stay on until the core is away from the magnet and not suffer and pull back from a too short trigger pulse.

Here is a dramatic graph showing the four time gain. The blue trace is just a single magnet, the red is both poles in a complete flux loop.

Ron
Adam Flux.png

[Matthew Jones]

But do you have way to narrow expand the pulse? I don't disagree with what your saying but currently you have no way of knowing whether a smaller pulse will push it away. You have a fixed Duty Cycle. Unless you have adjustment in there and some code. Mostly what I was addressing was the recovery factor.

Not sure I understand what your talking about with the 48 volt thing I briefly looked at the paper I'll read it. I do not doubt the benefits of going higher voltage the speed that the field shows up is faster and based on OHMS law the coil allows more current to flow. Whether or not the performance overall changes much that a subject for testing. Using both sides may or may not yield a gain but I am sure if anything it adds torque, why waist half the field. If your allowing the magnets to pull into the coil then ejecting them I cannot see where the flux path is a help other than maybe making the field a little bigger. The flux path would not be effected by the coils field only the fixed magnet.

That's just some stuff off the top of my head. I am not arguing with any of it, I was just pointing out the advantage planning the coil an switching cycle pre build. When I build this TS motor thats what I am working from first.

One thing forgot to mention is if you let that magnet pass the coil mostly before you fire it you very well may be able to generate enough power to recover the losses especially with an efficient battery. That's just something to think about in the timing of it all.

Lets keep going.
Matt

[i_ron]

To change the pulse length I can change the trigger magnet size. What I have in this version is a 23 ohm coil running on 48 volts. There is a good healthy fly back and the 1600 mfd cap will count up to 200, 300 volts very quickly. So I have tried various schemes and yours wins hands down. I see you show two P channel fets. I have tried a N channel in the low side and a P channel in the high side but P channel fets and I don't get along that well so have reverted to both N channel mos fets. Other than blowing up a bunch of stuff, when I did get to days show on the road it performed quite well. Here is a repeat of your jpg for this thread:

Matt_flyback addition to inp supply.jpg
Here is a pic showing the closed flux path, it is like a 'U':

20221104_131332_HDR.jpg

Ron

[Matthew Jones]

Are you any good with Arduino's? Might could interrupt between the hall sensor and the IGBT with the Arduino. Look for the magnet then fire. Timing might be kind a strange cause want it to be a percentage of the time between 2 magnets. But then again if what you got is showing a good result...

Matt

[i_ron]

Good day guys,

Well the usual problems with letting the smoke out of things but here is a short vid of the device running.

A run with no Matt recovery just a diode and resister to cancel the back spike gave a reading of 0.62 amps at 48 volts.

So I feel that I have achieved Matt's hoped for reduction of 50% at least from 30 watts down to 14.5 watts!

Ron

Matt3.png

[Matthew Jones]

That's great. Can you discharge the power to another battery. Or does that raise the amperage back up?

Matt

[i_ron]

Sorry for the noise but it is a work in progress and the hub has moved back towards one side as I don't have flats on the shaft and I didn't want to score the shaft up to much. It was quite quiet before but I wanted to do the video while it was still running! I have yet balance it also.

I am a bit hesitant to try that as it is running from one 12 volt battery with a DC DC inverter to 48 volts and so would need to run a buck converter...

I do recommend the C4D02120a diodes though, 1200 volts and 10 amps, near zero resistance, with two of them on there now (only one in the video) the inverter is putting out 47 volts to the motor while the cap runs at 48 volts. Loading the shaft down withe fingers sees the amps unchanged for a consider drop in RPM.

Anyway I am delighted with the draw reduction, I have never seen anything like that before!!!

Ron

[Matthew Jones]

Both the motors that I built with under this topology sound the same as yours. Chug chug chug....ect. LOL

I am happy for you.

Matt

[Matthew Jones]

Design.jpg I have the design for the TS motor all done in Freecad. I have all the calculations ready and I have all the parts, except for polycarbonate that needs to be milled, ready. The pic of the design is half ready. That only cause I need so much for milling.


It will be running next month. We'll see how it does.

Matt

[i_ron]

Thanks Matt, the next step for me will to get the second coil up and running and tidily it up a bit. So will be a delay in my posts also. Look forward to your T motor, looks interesting.

Open to questions, all

Ron

[thaelin]

Have to ask what the core of the rotor is made of? Aluminum? If so, could that cause a reverse magnetic pole in the center? Just a thought. Nice rotor tho. Thinking of doing a PETG 3D printed rotor to play with. Have some half inch by 1/4 inch iron flat bar for the U. Skate bearing inserts for now as not going to use shaft for anything.
thay

[Matthew Jones]

Have to ask what the core of the rotor is made of? Aluminum? If so, could that cause a reverse magnetic pole in the center? Just a thought. Nice rotor tho. Thinking of doing a PETG 3D printed rotor to play with. Have some half inch by 1/4 inch iron flat bar for the U. Skate bearing inserts for now as not going to use shaft for anything.
thay

I am curious, why would you put an aluminum core in coil that you need to make a magnetic field to push a magnet away. Aluminum wouldn't do that. Help me out...

Matt

[i_ron]

No Matt, he said 'core of rotor' and yes the core is aluminum. Bedini made his rotors of aluminum is why I felt it was safe to do so.
The shaft is nonmagnetic SS though.

Ron

[Matthew Jones]

No Matt, he said 'core of rotor' and yes the core is aluminum. Bedini made his rotors of aluminum is why I felt it was safe to do so.
The shaft is nonmagnetic SS though.

Ron

LOL well you know blonds have more fun.....LOL

I got everything cut today but couldn't go get screws so tomorrow or the next day I'll post screenshot of the progress,