Lockridge Device - Peter Lindemann

[n84dafun]

Motor running and tests

Here are videos of my motor running and pictures of the rotor wound in a zig-zag fashion:

YouTube - Lockridge-Modified Motor - Step 1

YouTube - Lockridge motor bogging down

YouTube - Lockridge motor power and capture brushes

Does anyone have any theory as to why the motor bogs down when I short the capture leads? I can't figure it out.

Brian

[Matthew Jones]

Here are videos of my motor running and pictures of the rotor wound in a zig-zag fashion:
Does anyone have any theory as to why the motor bogs down when I short the capture leads? I can't figure it out.

Brian

It may be that your generating to some extent. Pulling a load off of a generator will slow you down.
With the Zig Zag pattern your on time very well might not clear the coil from the magnet. Follow Me.
The solution may be to use 2 commutator blocks for the power cycle. That will throw the coil out of the magnets range before you start recovering.

Then again you may just want to setup a recover for higher voltage and run that thing with a higher amount of voltage. But you had better recover into batteries, those little caps fill up too fast.

Nice work though, I happy to see the motor worked out.

Matt

[Mark]

Peter

With the diode on the recovery brush being next to the negative brush it seems like it wouldn't be a real problem if there was a little bit of overlap. I'm getting ready to set up my brushes and want to make sure I collect all of the "spike". Too much of a gap and I'll miss it and too little of a gap and I'll have some overlap.

If the diode on the recovery brush was next to the positive brush we'd have power transfer with some over lap, I'm sure we dont want that. John K had posted a picture with this configuration a while back.

Just trying to figure out how critical the spacing is and if I should try to set up my brushes so I can adjust them.

@Brian
I dont think its a problem that the motor slows down when you short out the recovery or are attaching a load, I think thats normal.

[FRC]

Can Someone help ?

After seeing all your posts and videos about winding, and Peter mentioning that
the motor would be like a Bedini with more torque and no electronics. I went back and rewound the 5 inch fan from my failed Bedini fan kit. I posted this on another thread:

Ok, I rewound one of the coils with # 24 gauge and managed to break off one of the wires from another coil. So unwound that one. Rewound this one # 24 again so now even two of each. Put it back together, one set the motor works.
Other set does not. So if hooked up to circuit would get fan but no charging.
Current is going through coils that did not work. So does this mean that coil
was wound backwards instead of clockwise and has to be rewound?

Update
-------
Took fan apart again and reconfigured the wiring without having to rewind the coils. Now
all four coils are functioning properly.

FRC

[dragon]

I would think there shouldn't be any disruption in motor function when the recovery brushes are shorted. It should be a completely separate system from the motor. If it's operating like a generator at the point of discharge where when you short the leads it goes into full load opposing the rotation... maybe the diode should be reversed?
________
How to roll a blunt

[gmeat]

Brian, In your last video you posted it appears that you forgot to check for conduction between the second (white)power winding and your (black) recovery winding.So could you just confirm that for us so as we can be assured that this wasn't overlooked.Thx


-Gary

[FRC]

Current State

In my # 320 post. I just realized with the two poles working it could still be used in a Lockridge setup if I made a commutator with two sets of brushes.
I had not considered that for this motor.

FRC

[Peter Lindemann]

Various Problems

Brian,

Thanks for showing your pictures. The rotor wound with the Zig-Zag winding looks GREAT. All of the problems you are seeing are related to your brush arrangement. When you switch over to the one I have recommended in Post #306, and connect your rotor wires to commutator segments 180* away from each other, the motor should behave differently.

After that, we can look at what your recovery brushes are connected to, and a voltage source that can deliver more current.

Peter

[pattester]

@ Brian
I have done the same continuity tests as you with the multimeter and got the same expected results.
I shorted the recovery wires but my motor doesnt slow down.
With 12v input i get approx 6v recovery into a 4700uf 40v cap but i had to put the recovery diode on the brush after the positive input rather than the recovery brush after the negative as in Peters drawing.

My Motor is a 2 pole with only 1 coil, i dont know if this makes a difference?

Great videos

Pat

[Peter Lindemann]

Correct

Peter

With the diode on the recovery brush being next to the negative brush it seems like it wouldn't be a real problem if there was a little bit of overlap. I'm getting ready to set up my brushes and want to make sure I collect all of the "spike". Too much of a gap and I'll miss it and too little of a gap and I'll have some overlap.

If the diode on the recovery brush was next to the positive brush we'd have power transfer with some over lap, I'm sure we dont want that. John K had posted a picture with this configuration a while back.

Just trying to figure out how critical the spacing is and if I should try to set up my brushes so I can adjust them.

Mark,

You are right. A little bit of overlap is OK as long as the diode prevents conduction until the voltage reverses from the coil discharge. The main issue about the recovery brush placement is timing. The question is, how long does it take for the rotor winding to discharge? That depends on the impedance of the "load". A large resistor would take the longest. Dropping the discharge into a second battery would take the shortest. You want the recovery brush engaged long enough to fully discharge the winding.

A little overlap is fine. It prevents any arching when the power brush disengages and then leaves plenty of time for the winding to discharge to the second battery.

I don't think, for this first test, that you need to make your brushes adjustable.

Keep up the great work.

Peter

[Peter Lindemann]

Back EMF

@ Brian
I have done the same continuity tests as you with the multimeter and got the same expected results.
I shorted the recovery wires but my motor doesn't slow down.
With 12v input i get approx 6v recovery into a 4700uf 40v cap but i had to put the recovery diode on the brush after the positive input rather than the recovery brush after the negative as in Peters drawing.

My Motor is a 2 pole with only 1 coil, i don't know if this makes a difference?

Great videos

Pat

Pat,

Your recovery voltage is lower because you are seeing the "THE TRUTH" of the "effective voltage" on the winding. As you know from my DVD,
the Effective Voltage = the Applied Voltage - the Back EMF.

Observe carefully what your machine is doing. Even write down the behaviors, especially the ones you don't understand, and correlate them with the schematic drawing of the motor that produces those behaviors. Keep good notes of your experiments. This is the only way to learn.

Also, you are correct, shorting the recovery brushes should not slow the motor down, but always have then connected to "something" to prevent arching at the commutator.

Keep up the great work.

Peter

[Mark]

Well I've run into another problem. My commutators are a little longer than the ones Matt is using and after installing them onto the board they hit on bolt studs. So I'll either have to grind down 2 spots in the cover where the bolts screw in or grind 2 spots into the commutator board and turn it about 45 degrees. Or I could relocate all 4 commutators. The other thing with my particular motor is that my brushes are wider than 1 commutator section, not a big deal but not ideal. I think my best option will be to grind down the bolt hole mounts on the cover and just use 2 bolts.

@Matt

When you said you had a wire shorting out on your rotor I'm wondering if its acually the commutator case or prongs shorting out on the cover. Unless you ground down the 2 studs on the cover under the new commutator locations.

Mark

[n84dafun]

Brian, In your last video you posted it appears that you forgot to check for conduction between the second (white)power winding and your (black) recovery winding.So could you just confirm that for us so as we can be assured that this wasn't overlooked.Thx


-Gary

Gary, I tried all possible combinations of hookup and it is as expected. No conduction netween any recovery and power brushes. I think Matt and Mark are correct that the slowdown is expected and normal because of the generator effect you get when you pass a shorted coil through a magnetic field, which is what is happening when the recovery brushes touches the commutator and you short the recovery leads. This is normal. What's different is you also get the energy from the collapsing magnetic field due to pulsing the coil.

One thing I didn't do yet is put a diode om the recovery side. That's why I only get about 11V. Looking at the scope, I think I was getting 100v pos and neg spikes (at x10 mode on the probe). You can't get that from regular generator action I don't think.

By the way Mark, I had to add another set of contact points for the brushes on the commutator because the duty cycle for one segment of a twenty commutator rotor is too short. It would stop 3/4 of the way and stop. For my setup, I just connected one segment 180 degrees from the connected commutator segment of the pos brush and did the same for the neg brush. So there's 4 contact points all together.

Brian

[n84dafun]

Well I've run into another problem. My commutators are a little longer than the ones Matt is using and after installing them onto the board they hit on bolt studs. So I'll either have to grind down 2 spots in the cover where the bolts screw in or grind 2 spots into the commutator board and turn it about 45 degrees. Or I could relocate all 4 commutators. The other thing with my particular motor is that my brushes are wider than 1 commutator section, not a big deal but not ideal. I think my best option will be to grind down the bolt hole mounts on the cover and just use 2 bolts.

Mark

Mark,

That's exactly what I had to do to fit my recovery brushes...grind out two bolt holes. It's also a good idea to put electrical tape on the bottom of the board and at the ends of the brush housings.

Brian

[Peter Lindemann]

The Fun of Modifying Something

Well I've run into another problem. My commutators are a little longer than the ones Matt is using and after installing them onto the board they hit on bolt studs. So I'll either have to grind down 2 spots in the cover where the bolts screw in or grind 2 spots into the commutator board and turn it about 45 degrees. Or I could relocate all 4 commutators. The other thing with my particular motor is that my brushes are wider than 1 commutator section, not a big deal but not ideal. I think my best option will be to grind down the bolt hole mounts on the cover and just use 2 bolts.

@Matt

When you said you had a wire shorting out on your rotor I'm wondering if its acually the commutator case or prongs shorting out on the cover. Unless you ground down the 2 studs on the cover under the new commutator locations.

Mark

Mark,

My recommendation is to make the modification that is the easiest, namely grinding two large flats on the cover mount studs in question to give you more clearance for your brush holders. If you grind them from the inside toward the outside, you can probably gain up to an eighth of an inch clearance without losing the functionality of the mount stud. If you simply grind it down, you can get rid of it all together and then just use two mounting bolts to hold it together. Either way, you would not have to change anything else on the rotor to make this work.

From the pictures that Brian posted, it looks like your brushes are about TWO commutator sections wide. That is no problem for now. The spacing between brushes remains the same, at ONE commutator section width.

Just solve each problem as it arises. You are almost there.

Peter