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Peter Lindemann Rotary Attraction Motor

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  • Peter Lindemann Rotary Attraction Motor

    Hi All,

    I have decided to replicate Peter Lindemann's Rotary Attraction Motor. This design has always fascinated me, so I decided to replicate it. It's a no BEMF design and can be seen on the "Energeticforum Y-tube Channel" here and here . If I can get good results I would like to try driving a no-BEMF generator with it.

    I just started the build last week with an old DC motor I had lying around. It will probably take me a few weeks to get it finished. Here's a few photos of my first progress. DSC01280.jpg DSC01281.jpg DSC01282.jpg

    I removed the windings from the rotor, removed the brushes, and shaved the rotor down to match the stator width. Upon energizing the coils, it pulls the rotor into alignment with a fair amount of force. The original motor was rated at 1/10th HP, 7000 RPM, 12.5 Amps, and 12 Volts. I removed the gear reduction from it as it was originally designed to power a wheel chair.

    I experimented a little with magnets on a cast pulley and reed switches, but wasn't happy with the inconsistent results. I plan on using a hall switch arrangement instead, as I've achieved good results with that on one of my SSGs. And I may go to a non-magnetic flywheel as well. I want to be able to control timing and pulse width. I will be capturing the coil collapse with a fast diode and experimenting with various uses of the recovered energy.

  • #2
    What kind of no back emf generator would you use?
    Aaron Murakami

    You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete.” ― Richard Buckminster Fuller


    • #3
      Hi Aaron,

      Originally posted by Aaron Murakami View Post
      What kind of no back emf generator would you use?
      Not sure yet what to use. I was thinking of a flux gate, G-field, or Kromrey design. Possibly even a magneto type like used in the advanced SSG handbook. I'm open to any suggestions you may have!


      • #4
        Here you have more information Peter Lindemann Rotary Attraction Motor


        • #5
          Hi All,

          Got my rotary attraction motor up and running today after a few false starts. LOL I started out using an MJL21194 transistor, but it was running way to warm to suit me, so I switched it out for an IRFP4310 power mosfet. This thing runs cool as a cucumber! No heating anywhere in the circuits or coils.

          After experimenting with the timing I settled on a spot that gave good acceleration, moderate speed, and the lowest current draw. I hooked two lawn tractor batteries to it, both of which started with a resting voltage of 12.56 volts. It accelerated to 5500 RPM and immediately started raising the voltage of the charge battery while drawing about 510 ma from the run battery. It was developing more torque than I thought it might, and when loaded the charge battery started increasing voltage at a faster rate. And the current draw went up to about 700ma.

          Here's some photos from the first run. After maybe 15 minutes the RPM was up to 5600+ and the voltage was increasing on BOTH batteries.







          • #6
            And here's photos of the voltage increase on both batteries.





            • #7
              Nice work Gary


              • #8
                Hi Gary are you claiming a COP>1.



                • #9
                  Hi Andy,

                  Originally posted by Handy andy View Post
                  Hi Gary are you claiming a COP>1.

                  I'm not claiming anything at this point! What I posted was just the results of the first few minutes of running!

                  It does look promising, but I need to take several measurements over several long term runs. I also need to measure the mechanical output at the same time, in order to determine the total output compared to the electrical input. I was also using a couple of old, under capacity batteries which may have skewed the charge rate results. And it was running in radiant charge mode, as can be seen in the schematic drawing. I haven't tried it in common ground mode yet.

                  It does behave similar to my best SSG running in common ground mode, which requires only .8 amp hr to recharge this same battery after removing 1 amp hr from it. Notice I said amp hrs, not watt hrs. It's electrical COP is still slightly under one as can be seen when swapping batteries in a continuous run. They eventually both lose voltage. But it is also pulling a mechanical load of genny coils or two fans at the same time. So the TOTAL COP of that machine may well be unity, or slightly over. Here's a link to the post on that one where I forgot to take the watt hrs into account and only reported the amp hrs as COP.


                  • #10
                    Hi All,

                    OK, I've run this thing for several hours over the past three days and it exhibits very similar behavior to a regular SSG. The charge battery slowly charges and the run battery slowly runs down. It does, however, appear to produce more mechanical torque than a standard SSG while running on only 500ma. I hooked my scope to it this evening, and was somewhat surprised to also see nearly the same voltage wave form across the coil as an SSG.

                    The first scope shot shows about a 20% duty cycle, 205.76 cps (6173 RPM), and noticeable ringing throughout coil discharge. This is a lot more ringing than any of my SSG machines!


                    In the second scope shot, you can see the 6 volt radiant spike when the FET turns off. And you can also see some of the ringing over the rest of the wave form.


                    In the last scope shot you can see the pronounced ringing after the FET switches off.


                    Since there are no magnets going past the coil, I thought there would be less of an "h" shape and more of a triangular shape to the collapsing wave form. But then again, I was probably thinking in terms of current rather than voltage! Peter shows a triangular current wave shape in his presentation as shown in this photo.

                    Rotary Attraction Motor.jpg

                    Anyone have any ideas on why all the extra ringing shows up?
                    Last edited by Gary Hammond; 04-17-2017, 07:05 PM. Reason: add question


                    • #11
                      Hi Gary,
                      After referring to your drawing in post #5 my first wild guess is that you are picking up ringing off the batteries. Less likely would be an interaction between coils either electrically or fields. Last possible is you are developing capacitance some where in your circuit possibly in the windings.

                      It might be helpful to know the exact points you were probing for each display, but honestly probably wouldn't change my guesses.

                      I am not really much help just throwing some guesses out there.

                      I believe the triangular diagram you showed is supposed to be a representation of total input current vs total output current as a relationship and not necessarily what you would see on a scope even with a current probe.

                      Last edited by Michael Luton; 04-17-2017, 09:24 PM. Reason: typing error


                      • #12
                        Hi Michael,

                        Thanks for the response. The scope probe was attached to the junction of the FET drain with the coil and diode. The probe ground lead was attached to the other end of the coil at the junction with the primary battery positive lead and secondary battery negative lead. I also got the same overall wave form with the scope ground lead hooked to the primary battery negative lead (which shows the voltage across the FET).

                        I then removed the ammeter from the negative input lead as this reduces the slight ringing after the spike on my SSG. The only affect that had on this motor was to increase the free running RPM a little. And I noticed that when loading the motor down, the amplitude of the ringing increased but the frequency remained the same. I was able to measure this frequency at between 4.35 MZ and 4.55 MZ depending on how I had the scope set. It does reduce in both amplitude and frequency the farther past the spike it gets in time until it is mostly damped out. Then a much lower frequency sine wave appears on the scope trace which appears to be a harmonic of the pulse frequency of the motor.

                        On my SSG, a sniffer coil positioned close to any of the battery leads shows each current pulse to consist of an 833 KZ diminishing sine wave. I haven't checked that with this motor but suspect it would show the same thing. This is the same on all my SSG's, and I think it must be the resonant frequency of the batteries.

                        I'm guessing that the SSG greatly dampens the ringing in the run coil due to being multifilar wound and having a trigger winding that absorbs some energy and shunts some of it to ground thru the diode across the base emitter junction. This motor doesn't have any of that to dampen the high frequency ringing, which I assume must be due to the natural frequency of the coils - i.e. inductance and capacitance.

                        Like you, I'm just guessing at what I'm seeing on the scope. My biggest surprise was how closely it resembles the overall wave form of the SSG when there are no interacting magnetic fields (no rotating magnets) and a single filar coil with no trigger winding!

                        Now I need to get working on a small dyno to measure the mechanical output and then fabricate a small no-BEMF generator for a load!
                        Last edited by Gary Hammond; 04-18-2017, 11:48 AM. Reason: correct typo


                        • #13
                          Hi All,

                          I ran the negative secondary battery lead through my sniffer coil today, and the scope does indeed show the charge pulses resonating at 833 KZ just as I thought it might! This must be the battery resonant frequency affecting the charge pulse.

                          I was also able to measure the time period of the slower sine wave that can be seen riding on the back of the main wave after the spike. It is the sixth harmonic of the pulse rate thru the FET. I assume maybe this is caused by the resonance of the entire primary circuit?

                          That leaves the short 4.55 MZ damped ringing after the spike. I assume this could be the resonant frequency of the coil itself every time it is pulsed?

                          So I have four different frequencies showing up on the scope. The fundamental pulse from the timing wheel plus three more frequencies resulting from it's interaction with the various circuit elements.

                          The next step is to machine a new timing wheel with a 12" circumference. I just ordered some spring scales so I can measure torque and calculate the mechanical horsepower output. With fully charged batteries it got up to a no load speed of 6250 RPM this afternoon. That's getting pretty close to it's original design speed of 7000 RPM!

                          Any and all comments, suggestions, or observations are welcome!


                          • #14
                            You might be picking up the zener diode ringing in the fet?


                            • #15
                              Hi All,

                              Did a little more experimenting with it today by drawing a load on the charge battery while the motor was running. A 100ma LED strip allows the charge battery to still charge, and has no effect on either the current draw from the primary or RPM of the motor. And a 200ma LED load causes the voltage on the charge battery to go down very slowly with, again, no effect on the speed or current draw.

                              So the motor can deliver somewhere between 100 ma and 200 ma to a load hooked to the charge battery while still maintaining the voltage in the charge battery. This is similar to an automotive charging system except that it does it without slowing down the motor or adding any current draw from the run battery. I think this is pretty cool behavior.