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Author Topic: Has anyone seen Lasersabers new motor runs on 1000uf cap  (Read 294620 times)

conradelektro

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #120 on: June 06, 2013, 04:08:27 PM »
Hi Conrad,

A) Okay, thanks for clarifying this. I knew the diagram was ok, so the word "shorten" (to cut in length) did not cause problem. To put it simply: the reed switch discharges the 1000 uF capacitor via the coils and via the reversed biased diode (discharge current depends mainly on the reverse current characteristic of the diode and the AC impedance of the series coils).

B) I think when you connect the diode in parallel with the coils, this may need a different reed switch position than when the diode is in series with the coils.  The parallel diode keeps up the current in the coils when the reed already is OFF, so the reed needs to be in a position where its own ON time is less than in the case the diode is in series with the coils. IF you readjusted the reed to the parallel diode, then please disregard what I wrote.

C) Thanks for the measurements. You think now the waveform across the switch is not worth checking by the scope (when the diode is in series with the coils)?

Greetings, Gyula

ad A) It looks like the circuit turns into the simple circuit (only a diode) at the time when the Reed switch closes. The short time the Reed switch is closed seems to be enough to charge the cap in the usual way (by rectifying the sinus AC like current with the diode). I no longer see a miracle there. The diode is needed for rectification of the sine wave like AC generated by the coils. The reverse current of the diode seems to be irrelevant for charging the cap, only the forward Voltage is important (and should be as low as possible). The diode SB3100 seems to have a forward voltage of less than 200 mV and the 1N5711 only a little higher (as measured with my multimeter in diode test mode). The diode reverse currents is only important if one wants to run the setup as a pulse motor with such little current.

ad B) I tried to move the Reed switch around, and it is important where it is placed, but no difference in the optimal position could be found (with the diode parallel to the coil). Also with my "ring magnet spinner" I found that placing a diode (or LED) parallel to the coil had a small negative effect (the switch in the ring magnet spinner was a transistor at the same place where I have the Reed switch in my last charging circuit).

ad C) It is till interesting to do scope measurements, but first I want to go to a "double Reed switch". I see no special effect, therefore the incentive for me to investigate the Reed switch charging circuit or any charging circuit is low at the moment.

General remark:

Lasersaber claims to run his little 3D printed motors with less tan 1 µA. My motor needs 500 µA. This big difference can probably NOT be explained by lower friction in his setup and/or higher DC resistance of his coils.

I suspect it has much to do with the Reed switch ON-time which is about 50% in my motor. Therefore I want to go into the double Reed switch next (in order to bring the Reed switch ON time down to a fraction of what it is now).

I wish more people would build such a little motor so that we hear more opinions and get more test results. For me the only miracle left is the extremely low power consumption of Lasersabers 3D printed motors. Some information is missing and it has little to do with charging the cap when blowing air over the rotor. Just my gut feeling after my tests.

Greetings, Conrad

TinselKoala

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #121 on: June 06, 2013, 04:23:07 PM »
May I make a safety suggestion?

Builders of rotors containing magnets should not rely on glues or adhesives to hold their magnets in place. There should be some mechanical design feature that will absolutely prevent your magnets from being slung off the rotor when it's turning at high speed.

For example, in my Bedini motor I use a plastic jar lid for the rotor and all the magnets are mounted on the rim, but _inside_ the lid. A small bit of glue keeps them from sliding around but they are kept from flying off by the plastic of the lid itself. Other rotors I've made use cavities for the magnets but it is always impossible or at least very difficult for the magnets to fly off due to centrifugal force.

An uncontrolled NdBFe magnet flying across the room can be very dangerous. If it hits something it can shatter and red-hot bits of it will come flying off and may hit you in the eye. Or even worse.

Quote
I suspect it has much to do with the Reed switch ON-time which is about 50% in my motor. Therefore I want to go into the double Reed switch next (in order to bring the Reed switch ON time down to a fraction of what it is now).
You really should try a small biasing magnet on the side of the reed away from the rotor magnets. You might be surprised. Put the magnet on a small mount that you can hold steady and move around to find the best spot that will do what you want to the reed's duty cycle.

wattsup

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #122 on: June 06, 2013, 05:29:11 PM »
@conradelektro

Thanks for the testing and results.

I think that in your build the main limitation will be that they are 6 on 6. 6 magnets need 12 coils like @Lasersaber is using. The way I see it, there is 100% more usable energy in the 12 coils to make the same rotor turn.

The EZ motor should not need a battery or other input source.

But for your 6 on 6 we should not expect any more then what the effects show.

1) I did mention some time ago if you use a diode, then use a 1uf or smaller cap. Right now the diode and cap are more like a load then a pulse source. If you want to see some output, maybe put a diode between the last coil and the reed and the other side of the diode goes into a 100 or so cap and the other side of the cap goes to the first coil.

2) You tried with the reed on the negative side of the coil run. Maybe try it on the positive side as well.

3) Also maybe try the reed between coils 3 and 4. That is the most curious one for me when I get my one EZ motor type. hehehe

4) The other interesting and maybe easier alternative to your wheel is if you can add 6 more magnets, that would be 12M:6C and @Lasersabers is 6M:12C. Maybe that will give you more to work with and the extreme variance will be very interesting to experiment with in comparison to @Lasersabers.

5) The final variance is the magnet to coil surface area that we have to consider if we look at your results and compare it to @Lasersabers results. All of these factors will play an important role and any variance will affect the final results.

Thanks again for sharing.

wattsup


gyulasun

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #123 on: June 06, 2013, 07:35:37 PM »
Hi Conrad,

Thanks for your answer, I understand and respect your points.

I would make a notice on the double reed switch: maybe you will have a more versatile double switch if you make it yourself from 2 single reeds because a real double reed is more difficult to "adjust" with small magnets than two separate ones (also double reeds are harder to find, though not impossible)

Greetings, Gyula


conradelektro

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #124 on: June 06, 2013, 08:23:14 PM »
@TinselKoala: I just built a holder for the little biasing magnet and will test it tomorrow. By the way, the six magnets on the rotor have N facing outward (towards the coils), which polarity of the little magnet (on the opposite side Reed switch) should face the Reed switch? I guess it is also N? (I can turn the magnet around easily.)

@wattsup: thank you for the many suggestion, I will do what I can. So many possibilities. Looking forward to your build.

@Gyulasun: I intend to use two independent Reed switches which can be adjusted relative to each other. I did not know that one can buy a double Reed switch. I think that two Reed switches in series do not need biasing magnets, the determining factor for the ON-time will be their relative distance.

I try the biasing magnet (à la TinselKoala) first because it was easier to build (and can be done with one Reed switch only).

Does anyone have an idea why Lasersabers's 3D printed motors need so little current? My hunch is "very short Reed switch ON-time"? The DC resistance of his coils can not be much more than 2K to 3K Ohm in total?

Greetings, Conrad

conradelektro

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #125 on: June 06, 2013, 09:45:31 PM »
First tests with the biasing magnet behind the reed switch:

It is difficult to adjust the biasing magnet, but once I succeeded I got a dramatic reduction of power consumption down to a few µA (rotor still turning slowly consistently). The Voltage on the very weak AAA battery went up because the power draw dropped so much (may be a hundred fold).

Because it is so very difficult to adjust biasing magnet and Reed switch (relative position to each other and relative position of both to the rotor; too many variables), it seems easier to build an adjustable double reed switch, which I will do tomorrow.

So, I have very strong indication that "ON-time of the Reed switch" is the miracle behind Lasersaber's below 1 µA power draw. May be Lasersaber's Reed switch behaves differently than my model (which likes to stay in the ON state when close to the rotor and does nothing when moved away too far, a very narrow operating range distance wise)?

I have to learn a lot about Reed switches before I get this right! I also just realized that I never tried to position the reed switch above the rotor, I always had it next to it. So many things to do wrong!

Greetings, Conrad

lasersaber

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #126 on: June 06, 2013, 09:59:44 PM »

@conradelektro


Yes, the reed switch makes a huge difference.


This "How to Prepare a Reed Switch for a Pulse Motor" video might help: https://www.youtube.com/watch?v=5XfkejxtLgQ


Another video that might be helpful:  https://www.youtube.com/watch?v=WAPeC1JcZkI

conradelektro

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #127 on: June 06, 2013, 10:03:04 PM »
@conradelektro


Yes, the reed switch makes a huge difference.


This "How to Prepare a Reed Switch for a Pulse Motor" video might help: https://www.youtube.com/watch?v=5XfkejxtLgQ


Another video that might be helpful:  https://www.youtube.com/watch?v=WAPeC1JcZkI

Yes, that helps, thank you very much.

Greetings, Conrad

conradelektro

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #128 on: June 07, 2013, 04:41:54 PM »
I used a new Reed switch and also tried two Reed switches, but making the ON-time of the Reed switch shorter does not reduce power draw significantly.

The only way to reduce power draw (to e.g. a few µA) is to introduce a resistance into the circuit. Lasersaber does it with a diode and the reverse current of the diode is enough to drive his little motors.

My motor is mechanically inferior to Lasersaber's motors therefore I need at least "200 µA at 1 Volt pulses" through the coils to overcome all mechanical hurdles.

In order to use the same circuit as Lasersaber I have to place a 5.6 K resistor parallel to the diode. This resistor then allows for enough current to drive the rotor slowly at 1 V supply Voltage. It simulates a diode with a 5.6 K reverse resistance (about 200 µA at 1 Volt). Gyulasun, thank you for the idea.

I can then do the same as Lasersaber with his motors, namely speeding up the rotor by blowing air over it, which charges the 1000 µF capacitor quickly to about 6 Volt, and it then rather quickly discharges moving the rotor. The rotor stops when the charge in the cap is lower than 1 V. I can not reach more than a few 100 rpm, therefore I only reach about 6 Volt over the cap. Lasersaber can spin it up his motors to a few 1000 rpm and reaches therefore up to a 100 Volt over the cap.

I can of course drive the rotor by providing at least 1 V over the cap (e.g. with a battery or a power supply).

Conclusion: I replicated Lasersabers experiments but not in a very impressive way, because my motor needs at least "200 µA at 1 V pulses" to move the rotor. Lasersaber's precise mechanical setup allows him to drive the rotor with a few µA. He also seems to use bigger magnets and more windings on his coils. Important is also a precise alignment of coils and magnets and a narrow gap between coils and magnets, which is particularly bad in my build.

A different question is average "power draw". When my motor turns very slowly with a 1 Volt power supply, average power draw is well below 200 µA. It is difficult to measure because the Multimeter jumps between meaningless Values. I have to try measurements with a scope (over a shunt, e.g. over the 5.6 K resistor).

Greetings, Conrad

lasersaber

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #129 on: June 07, 2013, 05:14:06 PM »

Quote
The only way to reduce power draw (to e.g. a few µA) is to introduce a resistance into the circuit. Lasersaber does it with a diode and the reverse current of the diode is enough to drive his little motors.


Actually the 1uA motor in this first video had no diode in use.  See: http://youtu.be/Esphle_MsXI  The resistance comes from the 42 AGW wire itself.  At anything under 5V I would use no diode at all and tune for the lowest possible uA current draw.  Once you have achieved a current draw under 5uA with no diode then start experimenting with diodes.


I am also interested in hooking up one of these motors in an Adams motor configuration.   I also want to try using large flat 1.5" X 1/16" magnets with large thin pancake coils. I have so many ideas and so little time.

gyulasun

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #130 on: June 07, 2013, 05:40:49 PM »
Hi Lasersaber,

Could you measure the DC resistance of one of your coils, out of the 12 coils? Of course if you happen to have an L meter, the inductance value for a single coil would also be useful.

Thanks, Gyula

conradelektro

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #131 on: June 07, 2013, 05:42:05 PM »
Actually the 1uA motor in this first video had no diode in use.  See: http://youtu.be/Esphle_MsXI  The resistance comes from the 42 AGW wire itself.  At anything under 5V I would use no diode at all and tune for the lowest possible uA current draw.  Once you have achieved a current draw under 5uA with no diode then start experimenting with diodes.

@Lasersaber: what is the DC resistance of your coil (or all six coils in series) in your six coil motor?

Each of my six coils has a DC resistance of 90 Ohm, all six in series therefore about 540 Ohm.

Greetings, Conrad

P.S.: Power draw calculation for my pulse motor (over the resistor which is parallel to the diode):

Average power draw with a 6.8 K resistor is about 40 µA, with 2.2 K resistor it is about 120 µA. It also depends on the speed the rotor turns.

The reed switch is about 20% of the time ON.

conradelektro

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #132 on: June 07, 2013, 07:45:38 PM »
I did some scope shots over a 10 Ohm shunt to calculate average power draw of my little pulse motor at 1 Volt supply Voltage (no diode, just the shunt, see circuit diagram in attached drawing). And a scope shot over the Reed switch to show its ON-time (between 20% and 30%, depending on Reed switch position and turning speed of the rotor). I have chosen a 1 Volt supply Voltage to make the rotor turn relatively slowly.

My Multimeter measurement of about 500 µA was confirmed.

Why does my pulse motor draw about 100 times more power than Lasersaber's six coil motor?

Is it the impedance of the coils?

Is it the mechanical set up (specially the crudeness of the build)?

It can not be the ON-time of the Reed switch, because it could not be made 100 times shorter!

Comments appreciated.

Remark: The rotor can not turn faster than a few 100 rpm because it is badly balanced. With a supply Voltage of about 6 Volt it jumps out of its bearing (terminal speed reached).

For further details and a photo see this post http://www.overunity.com/13523/has-anyone-seen-lasersabers-new-motor-runs-on-1000uf-cap/msg362615/#msg362615

Greetings, Conrad

gyulasun

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #133 on: June 08, 2013, 01:10:15 AM »


Why does my pulse motor draw about 100 times more power than Lasersaber's six coil motor?

Is it the impedance of the coils?

Is it the mechanical set up (specially the crudeness of the build)?



Hi Conrad,

Thanks for the measurements.  I think Lasersaber's coils has much higher impedances (DC resistance and inductance) than yours, this could be main reason for his 1 uA current draw. 
Later I will comment if something useful occurs to me.

Greetings,
Gyula

Farmhand

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Re: Has anyone seen Lasersabers new motor runs on 1000uf cap
« Reply #134 on: June 08, 2013, 01:38:49 AM »

I think when you connect the diode in parallel with the coils, this may need a different reed switch position than when the diode is in series with the coils.  The parallel diode keeps up the current in the coils when the reed already is OFF, so the reed needs to be in a position where its own ON time is less than in the case the diode is in series with the coils. IF you readjusted the reed to the parallel diode, then please disregard what I wrote.

Thanks for the measurements. You think now the waveform across the switch is not worth checking by the scope (when the diode is in series with the coils)?

Greetings, Gyula

I would like to give my 2 cents on this point, it is one of the things I showed in the tests I did with my motor, when the coils are snubbed by a diode in parallel the current stops immediately as I showed, however when the coil can discharge into a higher voltage (such as a charge battery or some mechanism to allow a similar effect)  the discharge then causes current to continue after the switch (reed or whatever) is turned off. In my experiment the current waveform showed that the current ceased immediately when the coil was snubbed by a parallel diode, but continued for some time when a charge battery or other mechanism is used. I can show the shots but they are already posted in the other thread I guess I'll have to look for them where they are posted and provide a link.

When the coil is snubbed by the parallel diode the input is less than when a charge battery is used, adjustments need to be made to keep the input the same when these things are changed, Gyula is correct about that, but I do disagree slightly on the effects or the reason/cause. I'll show why. I'll need a minute.


The shots are at the bottom of the post, linked below. Top shots are clamped (with the snubber diode) bottom shots are with a charge battery. The bottom of the "drain" shots are angled because of where the scope ground is placed (not at circuit ground) the mosfets switch properly, it's just because of where the circuit is scoped. The top traces are the current through the motor coil, the bottom the mosfet drain.
http://www.overunity.com/11350/confirming-the-delayed-lenz-effect/msg359288/#msg359288

If I can clarify anything I just wrote please say so.  :)

Cheers

I think whats happening is when no snubbing diode is used the voltage is very high at the drain for some time, the effect of that exactly I can't say in conrads setup. But I think it would cause an effect different to snubbing and also different to a charge battery. With enough input it would destroy the mosfet. The snubber or the charge battery will save it but they will have different effects.

I think the scope shots show quite clearly the effect and I don't see any way it can be disputed. I did the experiment, I urge others to do it also and concur or disagree with my results, I can demonstrate the test on video. But that should not be necessary.

..