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Author Topic: Maybe possible idea for duplicating effect of Holcomb and others  (Read 27008 times)

bistander

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #45 on: August 27, 2022, 04:46:47 AM »
....
I did one more thing before dismantling that system.  I turned the slip ring current on the driving alternator up to several more amps to see what would happen.  I only ran it like that for a short time because of the heavy load on the scooter motor.  When I did that with the second alternator free to turn it took off like a regular motor and reached a pretty high speed very quickly.  I took a quick glance at the meters and the scope and there was barely any voltage being generated in the slip ring circuit.  I think this proves the induction into the slip ring circuit is coming from the moving magnetic field because when the rotor got up to close to the same speed as the moving magnetic field almost all induction stopped.  A quick glance showed less than a volt being generated as compared to 30 volts or so when locked even though the 3 phase field was much stronger.
...

Thanks for running that test and reporting. Results are as I suspected. It would not reach synchronous speed because as an induction motor it needs slip (difference between stator frequency and rotor frequency) to induce torque producing currents in the rotor (steel in this case). This slip frequency with no mechanical shaft load is very small, a few Hz at most. Therefore that frequency (and rate of change in flux) is what the shaft concentric rotor coil sees, hence the low voltage.

Great test.
bi
ps.
I like experimenting with the hobby BLDC drivers and breadboard FETs you guys are looking at. But those power signals (3-phase) differ considerably from a balanced true 3-phase source. So the resultant stator flux is unlikely to be a clean constant magnitude traveling magnetic field. More likely a sequence of pulses.

Feb2006

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #46 on: August 27, 2022, 05:19:39 AM »
I think you need to watch all the videos from the beginning so you will understand what we are experimenting with.  We are doing basic research on the idea of making a virtual moving magnetic field and the effect it might have on generating power.  The ESC I used uses PWM to generate a sort of sine wave.  Because the PWM pulses are so short they don't have time to generate a field into the slip ring coil because the impedance of the slip ring coil is too high for that short of a pulse.  An ESC such as the one in the second video UFO linked to probably has a simple on and off pulse without the PWM.  If that is the case then it should be able to generate a moving magnetic field like we are looking for.


I hope this helps you understand what we are doing.
Carroll


https://howtomechatronics.com/how-it-works/how-brushless-motor-and-esc-work/


"So, when the moving magnetic field of the rotor pass through the free coil, or the one that’s not active, it will induce a current flow in coil and as result a voltage drop will occur in that coil. The ESC captures these voltage drops as they occur and based on them it predicts or calculates when the next interval should take place."


No moving or wrong moving magnetic field results in wrong intervals.
The second video  half bridge ESC  can work a fuii bridge ESC that not predicts or calculates the next interval can also work.

picture is full bridge, half bridge has only one on and two off alternating.

Jimboot

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #47 on: August 27, 2022, 06:51:18 AM »
Thanks for running the tests Carroll. I went a salvaged an alternator today. Here is another of Zafers vids where he shows part numbers and circuit. https://youtu.be/geT94tV-xBM

citfta

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #48 on: August 27, 2022, 12:34:18 PM »
Hello Bi,
In the last video I posted I show on the scope that the RC ESC does use PWM or very short pulses to create a  simulation of a sine wave and therefore does not make a good source for our virtual moving magnetic field.


Hi Jimboot,
Good to see you here also.  I do plan to  build that MOSFET controller so the video is a help.  He does a good job of showing the actual build with part numbers.   But I need to draw that out on paper as a real schematic is the way I look at electronics.  I spent so many years troubleshooting circuits that is just the way my old brain works.  I just haven't take the time yet to draw it out.  I do think his circuit will probably give us a good signal for a virtual moving magnet field but only testing will prove or disprove that.


Take care guys,
Carroll

Ufopolitics

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #49 on: August 27, 2022, 06:33:30 PM »
Hello to All,

Well, I am very glad that I have triggered some interest from my previous post...

Please, let me first thank Feb2006 for clearing up something that I totally forgot to mention on my previous post:

The ESC we use here MUST BE a Sensorless or Hall-less type!!
Now, some ESC do not have an extra connection for the sensor, but uses one of the Phases at each interval of time, where that phase goes "inactive"...and these ESC Types are NOT good for the effect we need to achieve, which is a CONSTANT Rotating Field effect from the 3 Phases working at ALL TIME!!

@ Citfta, excellent testing my friend!!, basically your description and results about your first test, without the ESC...plus your conclusions that Rotor must be stopped in order to get max Output.

Now, on the second video with the ESC, I suggest you make a "rig" to be able to see the scope signal without all the scrambling you are getting...and again, it would be much better seen on a 4 Channel Scope....but I know you do not have one working...However, this will work as well just for one signal of the 3.

I took two images out of the link that Feb2006 posted: https://howtomechatronics.com/how-it-works/how-brushless-motor-and-esc-work/
And upload them here...

So on Image #1 He uses 3 resistors from the three phases and attach them together to create a "virtual common point"...as I suppose the resistance is supposed to be the same or approximated to each Coil resistance on the Motor (or in our case, the Alternator Coils).
Then attach just one of the gator clips to that common point (since it is just all clips are the same ground point for the scope).

On Image #2 You guys can see the three clean sinewaves seen at the Four Channel Scope (btw, very similar to mine, but mine is a DS110, not a DS105)

Anyways, Yes, I particularly like much better (like I mentioned on my previous post) the 3 FET Circuit that Zafer built...just because it seems more suitable for an Alternator set up like we will have...plus it uses that common point to regulate and control the three sinewaves.

Now, IMHO, if it can turn the Energized Rotor, even with a very small voltage from a 1.5V AA Battery...it does Generates a Rotating Moving Field.

Plus, if You make a simple test, I know it will also spin a N/S Radial Magnet inserted at center of Alternator Stator, mounted on a spinning shaft.

Now, with the ESC it does NOT generate the "Induction Motor Effect" which will turn a non magnetized steel rotor (like in Ctfta first videos, generated by the Alternator Generator)...it must be a magnetized Rotor here.

Take a look at Pierre Cotnoir setup, He uses a Magnet to verify the Rotating Field on his Six Poles rotary Field Stator...not a plain piece of steel as rotor.

Regards to All

Ufopolitics

Ufopolitics

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #50 on: August 27, 2022, 07:09:10 PM »
Hello again,

Here I have uploaded a third image from that same testing...which I wanted to discuss plus give my opinion.

I believe (am pretty sure off) that He is using the Sensing Type ESC for this test, just because it keeps having an "inactive" phase during intervals, and so switching on all 3 phases the inactive one..and this is done by the ESC Processor, in order to detect the right magnetic positioning of the rotor. So, that inactive (not sending power to it) circuit of coils, serves as a sensor, which feeds back the rotor magnetic positioning.

And that is why we need a Full, Sensorless Driver here.

Regards

Ufopolitics

kolbacict

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #51 on: August 27, 2022, 08:11:45 PM »
.but I know you do not have one working...However, this will work as well just for one signal of the 3.

maybe you forgot about the good old Lissajous pieces.
The CRT tube has four plates. And they are not afraid of overexertion.
It's just hard to interpret the resulting image.
This is how the hungry get out of the situation, who have nowhere to wait for help. :D

Ufopolitics

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #52 on: August 27, 2022, 10:01:26 PM »
Hello  to All,

I put together the basic schematics for Zafer Yildiz circuit based on 3 FET's...simple.

I may do sometime next week the symbols electronic schematics, as this is just as we saw it on video.

I found the best FETs are the AUIRF3205 which are Automotive Rated Spec's...a bit more expensive (like $4.36 USD ea) , but worth it, because they are heavier duty than typical board mount types...

I also uploaded the PDF Data Sheet for that FET...

They are 55V and 98A Rated N-Channels MOSFET.

Regards

Ufopolitics
« Last Edit: August 28, 2022, 01:27:35 AM by Ufopolitics »

Ufopolitics

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #53 on: August 27, 2022, 10:33:10 PM »

Hello,

Something I have noticed on Zafer Video...

Note when He accelerates the Alternator-Motor, with Potentiometer, the PSU shows no Amperage increase?
I find this property of this ESC, very useful for our purposes...
Here I uploaded two images from video...first one when he starts and a second one, once He accelerates Motor, note the Voltage increase,  while no amps increase.


Edit 1: Never mind, no big deal, I noticed He has CC on...or Current Control (CC) Limit.

Regards

Ufopolitics
« Last Edit: August 28, 2022, 01:45:30 AM by Ufopolitics »

citfta

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #54 on: August 27, 2022, 11:35:13 PM »
Hi UFO,


Thanks for the nice schematic.  Also the IRF 3205 mosfets he is using are rated for 110 amps at 55 volts.  I have used them many times and they are pretty durable.


Thanks again for your input.
Carroll
« Last Edit: August 28, 2022, 01:50:04 AM by citfta »

Jimboot

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #55 on: August 27, 2022, 11:57:50 PM »
Excellent thanks UFO. I’ll be using the irf1405 which I’ve used a lot in pulse motors and easily available to Aussie builders at jaycar.

bistander

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #56 on: August 28, 2022, 12:05:44 AM »
Looks like rotor field coil is powered by a 3.7V Li 18650 cell, not a 1.5V AA cell.
bi

Ufopolitics

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #57 on: August 28, 2022, 01:00:33 AM »
Hi UFO,

Thanks for the nice schematic.  I did find one mistake in it though.  You don't have any connections for power.  I modified it to show where the 12 volt power should connect to the circuit.  Also the IRF 3205 mosfets he is using are rated for 110 amps at 55 volts.  I have used them many times and they are pretty durable.

Thanks again for your input.
Carroll

Thks for the correction Citfta, but Bistander told me this was a "self energizing ESC"...Hahahahahahaha
Yeah, the FETs are available at DigiKey for like $1.59 when you buy 10...
Diodes are 1kV rated 1A...

I had some confusion about his gator clips (red-black) connections, as not seen completely on video, thks.

@Bistander, thanks for the correction about the small battery, it is about same size as an AA 1.5V...however it seemed too small of voltage for the coil.
I will be using supercaps plus a meter to see either gain or loss.

Cheers

Ufopolitics

Ufopolitics

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #58 on: August 28, 2022, 01:44:31 AM »
Excellent thanks UFO. I’ll be using the irf1405 which I’ve used a lot in pulse motors and easily available to Aussie builders at jaycar.

My pleasure friend!!
I am glad you are going to start working on this project!!
Regards
Ufopolitics

Jimboot

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Re: Maybe possible idea for duplicating effect of Holcomb and others
« Reply #59 on: August 28, 2022, 04:01:39 AM »
My pleasure friend!!
I am glad you are going to start working on this project!!
Regards
Ufopolitics
I’ve spent a lot of time looking for/fabricating a suitable rotor. This seems far more expedient. I want to clean up my alternator first :)