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Lockridge Device - Peter Lindemann

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  • Mark
    replied
    Originally posted by rosehillworks View Post
    Matt When you say "expansion" are you bridging commutator sections or are you just moving the place that the coil is connected to the commutator ?
    Rosehill

    We're "bridging" 2 sections together to get a longer duration and more current into the coil.

    Leave a comment:


  • rosehillworks
    replied
    Matt When you say "expansion" are you bridging commutator sections or are you just moving the place that the coil is connected to the commutator ?

    Leave a comment:


  • Matthew Jones
    replied
    Somthing NEW!!

    Woopy
    You've got me stumped, sorry.

    So what did I learn today. I have spent the last 3 days trying to get a bifiliar version running, No success.
    But I have tried several other things to increase the power on separate rotor but kept running into problems blowing diodes and very rough runs.

    The whole time I was under the assumption that the ZIG ZAG pattern was pushing my rotor.
    NOPE!!!!
    Its a puller.

    I went to reinstall my original rotor and noticed that I had set the commutator expansion ahead of the aligned slot, not behind.
    So to expand the commutator I have to set ahead.

    Now it may just be my rotor (I don't think so). I may have screwed up somehow, but just incase I wanted to let other know. If your getting hard bucking/cauging and slow speed well then you know what to try.

    Cheers
    Matt
    Last edited by Matthew Jones; 01-26-2011, 01:51 PM.

    Leave a comment:


  • woopy
    replied
    some diagrams for my comprehension

    Matt thank's a lot for the braking test-

    I don't see the difference between a pulse motor with brushes or with Any electronic switching.
    So far i see , the pulse duration is depending on the length of the contact between the brush and the collector section or the length of the trigger magnet for a Hall sensor.
    So if the length of the collector section or the trigger magnet is let's say10 degrees of the revolution . the pulse should be the same. Of course if the electronic circuitry is able to deliver the full power of the source power supply, as a brush does.

    So my experiments lead me to the diagram here under.

    On the left it is Peter Lindemann graph from his DVD
    I understand that this graph is for a DC motor with brushes where each brush is always in contact or with 1 collector section or bridging 2 collector sections. so the power from the source is steadily apply to the rotor windings on all the 360 degrees of rotation.
    So on the scope shot you see a steady line of the voltage and in the yellow part is the space for the BEMF to develop depending of speed.And as you can see this space is very large.

    On the right graph it is my expectation so far
    I understand that the brush is in contact with only 1 collector section per revolution. So it does not bridge on other section. So only one winding is fired per revolution, and this winding gives all the power.
    Further more if this winding is of large wire section , it will be able to conduct strong current (torque) and as it has low impedence it will also generate low counter voltage so the place (yellow) is very small for the develloping of the BEMF.
    So as Peter explain in the DVD we need winding of very low resistance to accept very high current pulsed once per revolution, to get strong mono-torque to spin the flywheel.
    Finally if we use a cap to pulse the motor . the distance between the pulse is time to recharge the cap. So if you pulse more than 1 time per revolution you will have less time to recharge the cap and you will have more space for the BEMF to develop.

    The problem with this one pulse motor is that it does not self start, or if you place collector section under the brush and you apply the power, the amperage will be huge, that is why i started the graph not at zero speed.

    This my understanding and please don't hesitate to correct me if i miss something

    Hope this helps

    good luck at all

    Laurent
    Last edited by woopy; 05-16-2011, 09:34 PM.

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  • n84dafun
    replied
    Rotor Mishap

    I haven't been able to do any more testing after the rotor in my motor malfunctioned. Also, I've been busy trying to catch up in my paper work, since I fell behind playing too much with my motor.

    I've been able to set up my motor so that it pulses twice per revolution using a couple diodes in the rotor. It's similar to what I drew earlier, but works with the power brushes at 90 degrees apart. The motor runs well, but the heavy duty diodes (1kV, 3A) were fairly big and caused imbalance and vibrations. I tried to balance things out by soldering a "dummy" diode on one of the unused commutators. However, the centrifugal force from applying 72V from my VariAC/FWBR/FatCap dislodged the dummy diode from its place and caused havoc inside the motor.

    There was also the problem with the wires coming off the windings at the rotor's edge and coming into contact with the magnets, causing it to flatten and break. It's a good idea to secure those wires by placing a piece of material like the bamboo stick that was originally securing the wires on the rotor. No wonder they put lot's of varnish on the wires, otherwise the wires would probably fly off from the spin force.

    I had another short circuit incident with my Variac again when running the motor with it after I placed the probes on the output leads of the motor. I thought I learned my lesson the first time. Anyways, it caused a big spark inside my motor and upon inspection saw what damage unprotected commutators could incur at high voltage and no recovery brushes for protection.

    I think I like my 4 pulse per revolution configuration the best because it doesn't use any bulky diodes and it is well balanced. Since I have a 20 pole rotor, and there are 4 pulses per rev, that means the duty cycle is 20%. Hopefully that's good enough to allow for cooling between pulses. I think Peter mentioned a 10% duty cycle on one of his posts.

    Another concern I have is that the current flow through the windings alternates direction every quarter turn, whereas the 2 pulse setup pulses only one direction through the windings per 180 degrees. In both cases, I noticed negative and positive spikes on the scope, which is strange because I thought it would only give unidirectional spikes on the 2 pulse setup, since current only flows in only one direction through the coil on every pulse.

    Once I rewind the rotor I can start testing again.

    Brian

    Leave a comment:


  • Mark
    replied
    Hi Tommy

    There are all different levels of knowledge, skill and expertise on most of the threads here. What you suggest is a good idea and may happen down the road. We're just getting started actually and are still trying to determine which particular motor, wire, voltage, etc. to use. So far there are only a few members reporting on their progress and we are still gathering which methods work best.

    If you read over the last 5-10 pages again you'll be able to get a better understanding of who's doing what. You could purchase one of the motors that have been talked about (there are links posted) and join in or wait until there is a little more progress. If you read thru the posts, look at the pictures and view the videos a few times you'll get a better grasp of things.

    Things should start to take shape in the next couple of weeks. My advise if your kind of lost right now is keep going over the posts and try to learn as much as possible before getting started.

    Mark

    Leave a comment:


  • tommy
    replied
    Such great information!

    I've spent the last few days reading every post in the forum on the lockridge device and wow what a lot of information. Hearing diode here and triad there, it became overwhelming and confusing. I have watched both of Peters Electric Motor Secrets videos and, as many of you, are very enlightened by his observations. But you guys are way far ahead of me on electric motors and design and construction.

    For education of myself and so people can easily pick up at the best practice scenario should they want to join in the research, may I suggest a file section that is moderated by senior members that details, one and only one, best practice motor for this topic? Then as better ways of accomplishing the goal is achieved, it is reviewed by senior members and if appropriate, replaces the current design. Again, this would ensure that newbies are starting from the best design.

    Just a thought and great work!

    Thanks

    Leave a comment:


  • rosehillworks
    replied
    Thanks Matt. I will keep working at the bench,

    William

    Leave a comment:


  • Matthew Jones
    replied
    It the windings that prevent it not the brush's.
    The way you wind the zig zag it want to go into attraction at 180 degrees.
    So you can only let it pulse 1 time per revolution.

    It works well, look at what Mark is getting out of it his.

    Matt

    Leave a comment:


  • rosehillworks
    replied
    Matt Why not use a set of points like your simple motor, and only interrupt the power just before and through the set of brushes at 90* and do the same for the set at 270* this would let you pulse two times every revolution, this way if the ends of your coil are connected 90* apart on the commutator you can bridge to trailing brushes at each of those to points this would let you collect the spikes like your simple motor if you open the points before the brushes go out of contact

    William.
    Last edited by rosehillworks; 01-26-2011, 03:03 PM.

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  • Matthew Jones
    replied
    It goes up. I have already burnt several holes in my glove trying to slow it down. The amperage can go up as high as 2.2 amp. But and that takes the motor down to around 2400 rpms.
    Thats the GLOVE TEST mind you.

    What you are doing is more a pulse motor. Using a hall sensor and and transistor or whatever will have that effect. All monopoles act the same.
    I am not sure how to explain it but I have seen the effect your showing several times. Reed motors, Hall motors and trigger wires all seem to display this. The coil chokes the flow of current or something along those lines.
    With a brush if you slow the motor down the brush stays in contact longer so there fore the current has more time to flow and its rate increases.

    I am starting a pony break tomorrow. I am going to try to do some torque tests that way.

    I have trying to come up with a way to fire 2 times per rotation every 180 deg without rewiring everything. So far no progress just a few fires.

    I am pretty convinced I will have to just use one wire and keep increasing the voltage.

    Cheers
    Matt

    Leave a comment:


  • woopy
    replied
    Braking test

    Hi Matt

    thanks very much for your great work here.

    Just a question , can you simply apply a hand braking on your rotor to see if per the same applied voltage . the amperage goes strongly up ( i mean more than double and more ) or it stay almost stable.
    I would like to check if you get the same results as per my experience in this video

    thanks

    and good luck at all
    YouTube - lockridge test 1

    Laurent

    Leave a comment:


  • Matthew Jones
    replied
    @pault
    You gotta look at inrush currents.
    Say if your motor is wound with 20 awg, maybe 100ft, and your running 72 volt your looking at something like 72 amp pulse for the first one, The inrush. Then your looking at something like 15 amp pulses after that when your induction takes hold.
    The pulse may take 1 millisecond and the off time is like 9 ms.Then you average out your 15 amp pulse over 10 ms and it look like 1.5 amp on an analog meter.
    Thats all just an example of course but you get the point.

    It why it is hard to say that something overunity or not. Pulse motors induction is a whole'nother ball game.

    If you have string of 7.5 amp hour batteries that add up to the voltage you need you'll be fine. Those batteries won't be harmed at all.

    I'm running 6 4.5 amp hour batteries and they are 6 years old. Brought back to life from a monopole and abused every day. They still have 95% capacity for there rating.

    Hope that helps some
    Matt

    Leave a comment:


  • Peter Lindemann
    replied
    None of the Above

    Originally posted by pault View Post
    If I understand correctly, I shouldn't run my batteries harder than their C20 rate for any appreciable amount of time. Currently the biggest battery I've got is 7.5Ah, with a C20 of 0.375A. This looks too low to run the motor w/o damaging the battery, given the results thus far.

    So, I probably need to acquire something more hefty. I have a bunch of choices. I've only been really active in this field since the conference (and only half-way through monopole3).

    Would someone with more experience like to suggest what might be the most useful of the below choices (which are roughly the same price)?

    a) 20Ah slab + tripler circuit
    b) 3A 30V variable bench supply (+ doubler or tripler circuit)
    c) 10A 0-250VAC variable transformer + fwbr + fat cap
    d) automobile (or other?) battery (+ tripler)
    e) Use what I've got (are we going to reduce current draw in future manifestations?) + tripler.
    f) ???

    Thanks
    pt
    Dear Pault,

    Most of these suggestions are inappropriate for this motor. It needs short, sharp, high current pulses to operate properly. The best supply is what Matt is using, which is a string of 12 volt Garden Batteries. If you restrict the current at the supply, the motor won't behave properly. Even though Matt's motor is showing 1 amp on the ammeter, don't be fooled. This analog meter is really showing an average draw that is more like 10 amps with a 10% duty-cycle.

    This motor requires big current pulses to operate, so there are NO PLANS to reduce current in the future. This is not a Bedini SSG, it's a high torque, high speed electric motor!

    Your best bet is option "C" with a cap after the FWBR of at least 100,000 uf. Even with this, the Variac will "moan" when the pulses go through!

    Make sure you have the recovery brushes in place before using this supply. Good luck.

    Peter
    Last edited by Peter Lindemann; 01-25-2011, 07:21 PM.

    Leave a comment:


  • pault
    replied
    Advice needed

    If I understand correctly, I shouldn't run my batteries harder than their C20 rate for any appreciable amount of time. Currently the biggest battery I've got is 7.5Ah, with a C20 of 0.375A. This looks too low to run the motor w/o damaging the battery, given the results thus far.

    So, I probably need to acquire something more hefty. I have a bunch of choices. I've only been really active in this field since the conference (and only half-way through monopole3).

    Would someone with more experience like to suggest what might be the most useful of the below choices (which are roughly the same price)?

    a) 20Ah slab + tripler circuit
    b) 3A 30V variable bench supply (+ doubler or tripler circuit)
    c) 10A 0-250VAC variable transformer + fwbr + fat cap
    d) automobile (or other?) battery (+ tripler)
    e) Use what I've got (are we going to reduce current draw in future manifestations?) + tripler.
    f) ???

    Thanks
    pt

    Leave a comment:

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