Has anyone seen Lasersabers new motor runs on 1000uf cap

[gyulasun]

Hi Conrad,

This pnp-npn or rather pnp - N chaneel circuit has an inherent positive feedback via the coupling capacitor (or earlier via the 100 kOhm) from MOSFET's drain to the pnp's base so it can inherently oscillate when both transistors are able to conduct and conditions for oscillation are present.
We can differentiate between AC and DC feedback and DC feedback was killed when you connected a series capacitor between the drain and the base, to break DC current conduction, now there remains to reduce the AC feedback.
You may wish to use a 10 kOhm emitter resistor: just connect the emitter of the pnp to one leg of a 10 kOm and the other leg of this resistor would go to the battery positive. And also use a 10 kOhm between the gate and source instead of the 100 kOhm so that the voltage gain of the pnp stage would be 1 (10/10).  Now omit the 10 kOhm in series with the 100 nF and maybe use a 100 kOhm potmeter instead of the other 100 kOhm resistor between the base of the pnp and battery positive, to have some means for further controlling (reducing) the AC gain.

To answer your question why the series 10 kOhm is needed: it influences the AC (and the DC) gain of the circuit (its role is similar to an op-amp amplifier circuit whose output is fedback by a resistor, say R2, to its input and there is a series resistor, say R1,  at its input to receive the input drive, so that the ratio of the two resistors, R2/R1 defines the gain of the amplifier stage).

Also, when you increase supply voltage, the voltage gain normally also increases, this explains why oscillation returns above a certain input voltage level where loop gain can become just enough aagain to cause self oscillations.

As SeaMonkey mentioned, the MOSFET remains OFF for too long but this is inherent in this setup because you used the ring magnet spinner setup, this explains the approximatly 50% ON time: poles can change in every half turns. In fact the ON time is less than 50%: perhaps the distances of the coils from the ring magnet are not equal? (I can see the left side coil is closer to the ring or only the angle of the camera makes it look like so?)

rgds, Gyula

[Magluvin]

@Mags: Your rotor, ring for the coils and base plate look professionally cut or turned? Did you have them made or do you have the right equipment?

Greetings, Conrad

Everything is made by me and no special tools really. An older Dewalt jigsaw using laminate blades. A cordless drill and some bits made for plastics and a couple sizes of Unibit.  And a dremel tool with an assortment of bits as needed.

The laminate blades come in scroll or straight cut. If you take your time, you can get some amazing cuts with nice edges. If it takes me 1/2 hour to cut 15in rotor from 1/2in plexi then Im happy. And I have it now.  Well, in 30 min.  Then with some sand paper finish the edges and Im good. The laminate blades do well with not melting most plastics.

When I have to make a rotor, I make the piece larger than my rotor size and find center then drill to size. If the material is thicker than 1/4 in then I find center on both sides and drill pilot holes half way through then finish of each side with Unibit to fit hobby shop bearings. This helps to keep your hole straight when drilling by hand or you might get a wobbly rotor because the top and bottom bearings are not always dead center if you didnt hold the drill perfectly straight just drilling all the way through from one side. Then I mount the piece to the bearings then on the base to check level. Then having a mark for the outer diameter I spin the rotor and mark the circle to be cut. The reason I do this at times is if I cut the outside precisely, if that center hole isnt dead nuts, all that time fine cutting the outer diameter was wasted. From there if trying to sand or cut to correct, the dia will be smaller than what I originally wanted.

I use superglues with great success, but I dont trust it for everything.Light sanding and clean of the surfaces helps a great deal for longevity. Sometimes Ill use superglue just to fix a piece in place and then apply either marine goop or epoxy. Goop and superglue are my favorites. There is a superglue called ' Wonderlock em Tite Chairs"  It has a couple fine nozzels and it is the thinnest superglue Ive experienced. A tiny bit can be applied and cures quickly. Pvc board loves superglue. The bond is almost always stronger than the material itself. Excellent building material. I like to work with plexi a lot also.

Mags

[Magluvin]

Beauty.
You could even make a winding set like UFO's asymmetric fantasy mogen.

Just kidding.... that's looking very very nice, I am impressed.

Thanks. Ats what I do.     Speaking of UFO, remember the thread where we talked about Farady paradox, Nmachine stuff?  Well Im going to incorporate one of the ideas I presented back then into the rotor.

The magnets will be in the edge of the rotor facing out. Im going to cut slots in line with the mag holes, inward from the outer diameter just about a 1/8 in deeper than the magnets. Before I insert the magnets im going to wind the 42 awg zigzag in the slots around the rotor. Like I start under the rotor in one slot then over to the next slot and down. the mags will be NSNS so as the rotor spins the N induce current up and the S induces a current down, all using the back sides of the mags. Im just going to wind till im tires of winding or that its all I can fit. The connect to leds or something. Possibly even a couple slip rings with light brushes to see if any voltage can be measured. If it works, it should work without the stator ring if I can get it up to speed, what ever that is. I figure wile I have the idea in my head, just incorporate it here.

If the rotor winding does produce current with the magnets and rotor coil in motion, but the mags and coil are solid with each other, heck, it might be just what we are looking for here at this wonderful site. A solid rotor that develops its own power when spun could have its output directed toward motor action with some stator mags and some reeds. Will see what happens.


Mags

[Magluvin]

I'm curious...do you have any information or help for replicating this device from lasersaber ?

Hey Forest

Laserhacker.com

There is a forum there for the 'EZ Motor"

Laser uses a 3D printer to make just about everything other than the wire, magnets and the needle rotor shaft with jewel as bearing. If the thing can be printed cheaply the rest is 6 magnets, about 15 bucks in wire and what ever the needle and jewels cost. he has a list of sources in the thread.    With 3D printer file for download, in case the is a 3D printer shop in town or if someone has a printer.


Im doing my own version with more coils and magnets. Also my coils are thin from front to back. I think with air core particularly, the field is weaker further away from the magnet for generators, so I want most all the wire in the coil being affected to be be in the same field strength as the rest. So the longer or deeper the coil, the windings further from the rotor will experience less field density than the windings closer to the magnets. With cores, such as seen in commercial motors and gens, the fields are controlled as to where they go, where they 'snap' when 'cutting' windings.    So I believe for air cores, the length of the coil for motors doesnt mater that much, but for gen, the shallower the better. Here with Lasers motor, it is motor and gen with same timing. As its running if you give the rotor a bit of a speedup by hand or blow air, the cap voltage rises to the speed the rotor is spinning, and will then be running at that voltage/speed. Very cool little motor.



Mags

[conradelektro]

@Gyula: Thank you for your suggestions and remarks. I will incorporate your teachings in my further tests of this circuit. My goal is to have a circuit that drives a pulse motor reliably and efficiently without any sensor. In principle we already have such a circuit (from DadHav), it just needs refinement.

The DadHav circuit for my "Lasersaber 3D printed motor replication" is still working und runs the motor for weeks on a 1.5 V battery, see  http://www.overunity.com/13523/has-anyone-seen-lasersabers-new-motor-runs-on-1000uf-cap/msg363823/#msg363823. A new version (with 1600 Ohm DC resistance coils) is held up by my experiments with the DadHav circuit, which captured my attention.

I ordered some more PNP and NPN transistor pairs for further tests. For very low power and low Voltage applications I will try BC557/BC547, BC327/BC337, 2N3906/2N3904, MPSA56/MPSA06 and for higher power and higher Voltage motors a PNP transistor with a MOSFET. Also MPSA92,93,94 / MPSA42,43,44 look interesting for up to 400 Volt (to resist high Voltage spikes from the drive coil). All these transistors are not expensive.

@Mags: Thank you for explaining your work methods. I am amazed what you can do with such simple tools. And it encourages me to try myself. I am following your build with great interest. So few really build something.

Greetings, Conrad