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Author Topic: Pulse motor build off time.  (Read 115521 times)

MarkE

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Re: Pulse motor build off time.
« Reply #135 on: December 03, 2014, 01:38:53 PM »
If for purposes of simplicity we assume that your coils have no resistance, and are linear, then each coil dumps an energy:  EIND = 0.5*L*I2 into your capacitors.  The resistance of the circuit plus the switch must dissipate that energy as heat each cycle.  Total up the coils, multiply that by frequency at which each coil cycles and multiply by the current squared divided by two and you have the average powe tht will be dissipated.

ramset

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Re: Pulse motor build off time.
« Reply #136 on: December 03, 2014, 03:28:41 PM »



here we have another entry ready for prime time


https://www.youtube.com/watch?v=tgX5cz1SMiw


enjoy


@Toad
keep a flipper to the ground [sending a PM]
[not sure if toads have ears....  ]


thx
Chet

TinselKoala

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Re: Pulse motor build off time.
« Reply #137 on: December 04, 2014, 02:12:51 AM »
That one should be called the "OnanMotor".   ;)

Meanwhile, the MescalMotor, which started as a project to reverse engineer the electronic Levitron, is coming along nicely. It's just a little toy compared to those ones up above, but it contains a few basic concepts that might be useful to other builders. Self-timed by shadows falling on CdS photoresistors configured as a "light operated potentiometer" which is fed to one of the inputs of a 741 bipolar-supply op-amp (the other input gets a feedback from the driver stage to smooth out the shape of the output response ramp). The Output of the op-amp then drives the bases of the PNP and NPN transistors in the push-pull output stage, which then drives the electromagnet coil, reversing its polarity according to which photoresisitor is shadowed by the ends of the sliding rod. The rod has magnets simply stuck to the ends in a NS===[coil]===SN configuration so that the coil attracts one side and repels the other side, and swaps when the coil polarity is flipped by the push-pull output stage. Push-pull, get it? The magnets have little grommets glued to the outer ends and a 5mm plastic air-soft BB inserted into the grommet hole, to make a nice striker for the piezoelectric elements which are mounted so that they bend a little bit when struck. It took me a few hours of trial and error to get the right mounting strategy for these elements that gave the highest voltages when struck by the oscillating rod. The outputs of the piezos are "alternate-parallel" into the fullwave bridge of 1n5817 Schottky diodes, and a 470 uF capacitor on the DC side of the bridge. From a cold start, it takes about 30 seconds to pump up the capacitor to where it will light up the green LED, which starts glowing at about 2.05 V or so. The piezo generators supply enough current now, though, to allow the voltage to climb as high as 2.22-2.24 V, which indicates that the LED is getting plenty current to glow fully bright. With no load on the FWB, the capacitor voltage will  climb to just under 9V... all on the output of the two small piezo buzzer discs alone.

http://www.youtube.com/watch?v=HTDitrH3glI

It's not nearly as elaborate as Tommey's motor, nor as powerful as the electromagnetic generator in the video above... but I didn't spend one cent of "new money" on it, it is entirely built with scavenged parts or parts and supplies purchased a long time ago for other projects. The Piezo discs, for example, have been kicking around in my junk box for around 12 years, I bought them at Halted Sales in California for about 5 cents each, still have 20 or so to use up somehow. Transistors salvaged from an MRI control board, wires from old CRT monitor cables, magnets bought a long time ago for magnet motor projects, CdS photoresistors donated by Fried Mike, op-amp from CRT monitor,  etc etc. All stuck together with Gel Superglue from the Dollar Store, two tubes for a dollar, can't live without that stuff any more, it works fast and sticks just about anything to anything else, works very well with the wood I use for frames, which is lauan mahogany plywood floor underlayment 5mm, also very cheap.

hoptoad

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Re: Pulse motor build off time.
« Reply #138 on: December 04, 2014, 08:45:01 AM »

here we have another entry ready for prime time
https://www.youtube.com/watch?v=tgX5cz1SMiw
enjoy
@Toad
keep a flipper to the ground [sending a PM]
[not sure if toads have ears....  ]
thx
Chet


And now for something completely different ...... great video. That is certainly a different design approach. I love the imaginative yet simple designs that go into some motors. Does that central piston (magnet ?) follow a spiral path as it goes up and down the shaft ? I've got a pretty poor resolution screen and its hard to see some things very well.


Cheers.

ramset

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Re: Pulse motor build off time.
« Reply #139 on: December 04, 2014, 01:00:07 PM »
There is an additional Prize offer in the wind ....
we shall see if it gets the OK .


has to do with Looping....?


good stuff indeed.


thx
Chet

TinselKoala

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Re: Pulse motor build off time.
« Reply #140 on: December 04, 2014, 11:22:51 PM »
@hoptoad: the plunger, if it does rotate as it goes up and down, is doing so because of mechanical effects, not any "magnetic vortex". However I don't think I see any rotation. The plunger shaft in my MescalMotor may occasionally rotate, due to the offcenter striking of the balls on the ends of the shafts, a mechanical effect similar to the way the camshaft will rotate the valve lifter bodies (as designed) by offcenter striking while an internal combustion engine is running.


Here's a scopeshot of the raw piezo output from the MescalMotor as shown in my video above, just for documentary purposes. This is with the FWB/Capacitor/greenLED load in place. The unloaded output has spikes that go over 9V. (18v p-p)


hoptoad

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Re: Pulse motor build off time.
« Reply #141 on: December 05, 2014, 04:36:23 AM »
@hoptoad: the plunger, if it does rotate as it goes up and down, is doing so because of mechanical effects, not any "magnetic vortex". However I don't think I see any rotation.
snip....


Thanks TK. I couldn't work out if their was a spiral groove on the shaft or it was just the springs that made it look that way.

hoptoad

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Re: Pulse motor build off time.
« Reply #142 on: December 05, 2014, 08:24:38 AM »
I don't know if Lasersaber is entering the pulse motor build off or not, but here's another great offering from him on YouTube.

https://www.youtube.com/watch?v=pVquLozWVm8&list=UUIKzUKkh7XtnSYPW0AJb-9w

Cheers.

TinselKoala

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Re: Pulse motor build off time.
« Reply #143 on: December 05, 2014, 08:39:57 AM »
I don't know if Lasersaber is entering the pulse motor build off or not, but here's another great offering from him on YouTube.

https://www.youtube.com/watch?v=pVquLozWVm8&list=UUIKzUKkh7XtnSYPW0AJb-9w

Cheers.

It's interesting, isn't it, that he can use a DMM as a voltmeter to get a voltage reading, then simply change the switch setting and get a current reading, without changing any wiring connections. I sure wish I had a DMM that worked that way, it would save a lot of trouble.


hoptoad

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Re: Pulse motor build off time.
« Reply #144 on: December 05, 2014, 11:48:01 AM »
It's interesting, isn't it, that he can use a DMM as a voltmeter to get a voltage reading, then simply change the switch setting and get a current reading, without changing any wiring connections. I sure wish I had a DMM that worked that way, it would save a lot of trouble.


LOL. - As usual, in my Over exhUberance, I didn't notice the little details !   :P

gyulasun

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Re: Pulse motor build off time.
« Reply #145 on: December 05, 2014, 04:33:33 PM »
It's interesting, isn't it, that he can use a DMM as a voltmeter to get a voltage reading, then simply change the switch setting and get a current reading, without changing any wiring connections. I sure wish I had a DMM that worked that way, it would save a lot of trouble.

Hi TinselKoala,

I was also surprised to see how he checked the current, just turning the usual rotary switch but not re-plug from the Volt input to the Amper input...  and I managed to capture a snapshot from his video where the labels are just readable enough, see the attachment.

So there are such DMMs that are able to measure current and voltage using the same input plugging to both, I did not know about this. Here is a link to this meter type he uses:  http://www.southwiretools.com/tools/tools/10040N   and there are only 3 inputs instead of the usual 4: from left to right there is the 10A, Common and the 3rd is all the rest (Volt, Ohm, Temp ect).

Gyula

TinselKoala

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Re: Pulse motor build off time.
« Reply #146 on: December 05, 2014, 05:31:48 PM »
Hi TinselKoala,

I was also surprised to see how he checked the current, just turning the usual rotary switch but not re-plug from the Volt input to the Amper input...  and I managed to capture a snapshot from his video where the labels are just readable enough, see the attachment.

So there are such DMMs that are able to measure current and voltage using the same input plugging to both, I did not know about this. Here is a link to this meter type he uses:  http://www.southwiretools.com/tools/tools/10040N   and there are only 3 inputs instead of the usual 4: from left to right there is the 10A, Common and the 3rd is all the rest (Volt, Ohm, Temp ect).

Gyula

What do you mean, "The usual 4" inputs? I have six or more DMMs from different manufacturers that have only the usual THREE inputs. The only one I have that has 4 inputs is the Fluke 83, and its "4th" input is a fused high-current Amp input. The other three usual inputs are assigned, one to volts and ohms, one to mA and uA, with one common for them all. The cheapo 3-jack meters have one _unfused_ 10A input, and one fused  V/mA/ohms input, and one common.

The point is not how the plugs in the meter are wired but how the meter is connected to the circuit. If you monitor voltage, you connect the meter directly _across_ the output of the voltage source you are monitoring. If you then simply switch the meter to the "amps" range, you are then creating a short-circuit through the meter. This will of course give you the greatest current reading you can get from your source: the meter in the amps range is a _very_ low impedance "load" on the source and the true voltage (unless regulated) will drop.  This is not the way power output is measured.

But I have exchanged notes with Lasersaber and he confirms that he did it this way deliberately to see what the short-circuit current was capable of reaching with his motor. He's putting a note in the Description of the video to clear up any confusion. Of course he is smart enough not to use such readings as a claim of "power output" and later on he'll be providing proper power readings: Voltage meter (high impedance) in parallel across a load, and Current meter (very low impedance) in series with the load, simultaneous readings from two meters.

The very best current meters have _zero_ resistance or as close to it as possible. If you take apart a cheapo DMM you may see the current-viewing shunt: A piece of heavy copper wire. These meters measure current by looking at the voltage drop across this very low resistance shunt and displaying the result as a current. Even analog, moving-coil panel meters will usually measure current in a similar fashion: they will have a shunt -- a veritable short-circuit -- between the meter terminals that handles most of the current while the meter movement itself only gets a small part of the current. This is done so that the "insertion loss" of having the meter in the circuit is small.

gyulasun

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Re: Pulse motor build off time.
« Reply #147 on: December 05, 2014, 06:14:07 PM »
Hi TK,

On "the usual 4" inputs I mean 1)the High current, 2)the mA, 3)the Common and 4)the Volt Ohm etc inputs.
I have a FLuke 87 which should be similar to your Fluke 83, with 4 inputs.
In the cheapo category there are types also with 4 inputs like this here:
http://www.ebay.co.uk/itm/LCD-AC-DC-Digital-Voltmeter-Multimeter-Ammeter-OHM-Auto-Voltage-Current-Tester-/161369748719?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item259262f4ef 

You are correct there are many DMMs which have only 3 inputs and probably there are many types with 3 inputs vs the 4 ones. In my enviroment, when I was active, the 4 input DMMs ruled, though we had several types with 3 inputs too.

I agree, the point is how the meter is connected to the circuit when V or I measurements are done and I forgot about this completely when answered, very sorry for this, I must have had a 'short circuit'.    :( :o

Thanks for your kind answer.

Gyula

TinselKoala

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Re: Pulse motor build off time.
« Reply #148 on: December 06, 2014, 02:02:12 AM »
You're welcome and thank you for the response. I'm always kind... just not always to everybody.  :P

Meanwhile, back at the lab...


http://www.youtube.com/watch?v=jGmbN1CzmsQ

Lakes

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Re: Pulse motor build off time.
« Reply #149 on: December 06, 2014, 10:16:28 AM »
Hmm... Attach piezos to soles of shoes, add led... night runners?? :)