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Author Topic: Selfcharging cap circuit from Larskro fake or real ?  (Read 85561 times)

Farmhand

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #90 on: May 29, 2014, 09:53:15 PM »
I may have found a possible "Tell" in the video below. If you play the video from 1:00 minute when he says "loop on" the camera goes to the meter then we can hear an audible click in the background (like the sound of a switch) the rpm increases. Then at the end why does he say "stop" ? Is he telling the machine to stop or his assistant ?

https://www.youtube.com/watch?v=g1tvbb_LDTM&list=UUjoIJFCH3ebq24jeqf11mfg

I wouldn't rule out a hidden batter in that thick board or hidden wires or other such mechanisms.

I've got glass reeds ( they look like they come from the 70's going by the packaging)  but no super capacitor.

..

TinselKoala

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #91 on: May 29, 2014, 11:15:38 PM »
Hmmm.... I'll have to watch that one closely several times.


Meanwhile, I've been playing with the MiniPulse.  I've changed the mosfet for a BC337-25 NPN, switched the 10R to a 1K and removed the 1Meg. Now the MiniPulse runs all the way down to the cutoff voltage of the Hall sensor which turns out to be 2.37 volts!  At 2.7 volts the rotor turns at about 2800 rpm, a very reasonable (and quiet) speed, and the system still makes spike voltages of 6 or 7 volts. Input power draw is right at 100 mW at that speed.

But of course at higher voltages the little bipolar cannot take the strain. I've got a handful of them so I think I'll run one to destruction just for grins.


As far as supercaps go... I am just starting to learn about them. I got three, 10F 2.7 volt units from an Ebay seller for about 4 dollars US, free shipping. I may have to order some more!

I have learned this much: high F capacities take proportionally longer to charge. A 100 F cap might be useful for a lot of things, like very long run times, but if your charging source is low-powered you will be waiting for a long time for the charge to accumulate in the cap. Also, the fact that energy depends linearly on capacitance but quadratically on voltage becomes increasingly important. Double the voltage you get 4 times the energy storage. Double the capacitance, you only double the energy.
I think I got lucky with the 10F value, it is a good compromise between charge time and total energy storage. Stacking 9 in a 3 series-3 parallel arrangement to give an 8-volt stack at 10 F would be a nice setup.



TinselKoala

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #92 on: May 30, 2014, 12:22:12 AM »
Now wait just a minute. If we have the schematic correct, when the thing has the battery unplugged and the switch in the "loop OFF" position, the reed switch is completely and totally out of the circuit. Right?

So why does the motor run at all? Only the reverse leakage current of the Shottky diode, coming from the caps, should be getting to the coil of the motor, and this should be a tiny tiny DC current.

Why does the motor run at all when the battery is unplugged and the switch in in "Loop OFF" position? Is it just coasting?





penno64

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #93 on: May 30, 2014, 12:24:04 AM »
Wilby kept a copy of smsat's video -

https://www.youtube.com/watch?v=rySqz7Hgpkk

no battery

TinselKoala

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #94 on: May 30, 2014, 12:50:29 AM »
Yes, but look at Larskro's schematic. When the battery is disconnected and the switch is in "loop OFF" position the reed switch is disconnected completely. Yet the motor runs slower, but still appears to run. It's not slowing down fast enough to be completely unpowered in that state, I think.

How can this be?

callanan

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #95 on: May 30, 2014, 01:33:29 AM »
It's a slide switch. It connects the battery's positive to the reed switch in the loop off position.

Pirate88179

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #96 on: May 30, 2014, 02:07:34 AM »

I may have found a possible "Tell" in the video below. If you play the video from 1:00 minute when he says "loop on" the camera goes to the meter then we can hear an audible click in the background (like the sound of a switch) the rpm increases. Then at the end why does he say "stop" ? Is he telling the machine to stop or his assistant ?



Geeze, this sounds really familiar...does anyone remember....

"You can turn it off now Tony..." from the Mylow saga?

Nice catch Farmhand, that went right past me.

Bill

TinselKoala

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #97 on: May 30, 2014, 02:07:47 AM »
It's a slide switch. It connects the battery's positive to the reed switch in the loop off position.

That's a pretty good trick... since the battery is _unplugged_.  Can you tell me where I can find such a slide switch?


https://www.youtube.com/watch?v=g1tvbb_LDTM
0:41

TinselKoala

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #98 on: May 30, 2014, 02:17:12 AM »
Meanwhile, here's MiniPulse II, with bipolar transistor instead of mosfet, running down to the limit of the Hall sensor's switching at just under 2.4 volts. Runs well on supercap, makes spikes 3x input voltage but still no voltage climb effect. I can't find any reed switches in my stashbox....   :(

http://www.youtube.com/watch?v=gC5GiLVCUPM





Farmhand

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #99 on: May 30, 2014, 05:42:21 AM »
OK can anyone give a fairly accurate approximation of how much "energy" can be stored in 20 mAh NiMH battery as compared to a 0.47 Farad capacitor both at 3.7 volts.

A 0.47 Farad cap has 3.22 Joules according to the electronic assistant app.

A 20 mAh battery at 3.7 volts should give 20 mA for an hour at about 3.7 volts ? about 266 Watt seconds ?

Clearly I've confused myself. I think.  :-[

Tinsel, another cool little motor. Strobe attack is neat too.

..

Maybe I should try to test the battery and see what I can get out, try to plot a curve or something.

..

TinselKoala

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #100 on: May 30, 2014, 07:35:13 AM »
OK can anyone give a fairly accurate approximation of how much "energy" can be stored in 20 mAh NiMH battery as compared to a 0.47 Farad capacitor both at 3.7 volts.

A 0.47 Farad cap has 3.22 Joules according to the electronic assistant app.

A 20 mAh battery at 3.7 volts should give 20 mA for an hour at about 3.7 volts ? about 266 Watt seconds ?

Clearly I've confused myself. I think.  :-[

Tinsel, another cool little motor. Strobe attack is neat too.

..

Maybe I should try to test the battery and see what I can get out, try to plot a curve or something.

..
I agree with your numbers, except that the battery discharge rate will affect its "capacity" somewhat. So you've demonstrated that the battery holds a lot more energy than the capacitor does, at that same voltage.
So to get the same energy storage you would need, say, 40 F at 3.7 V. That would give you (40F x 3.7V x 3.7V)/2 = about 278 watt-seconds.
Or you could charge to 8 volts... then you only need about 9 Farads or so.

d3x0r

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #101 on: May 30, 2014, 07:37:26 AM »
For the short time I played with it, I only saw a rundown effect; the motor doesn't really have a lot of flywheel mass... might be a sphere or differently enginerred in others; Any postive spike was invisible; maybe the captance was too high; but once any pulse from the coil of what should have been more then the cap had no appreciable effect; maybe the resistance of the scope probes is high; because right, without the reed switch there should be no power draw, and there was 100mA at 5V something... 

but I also still have the temp sensor and existing LEDs from the device attached in parallel.....

I like the idea of a 4000 turn coil primary/secondary to see the same thing :)  It's just going to be a longer slowdown... increasing H instead of F

d3x0r

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #102 on: May 30, 2014, 07:43:02 AM »

Tinsel, another cool little motor. Strobe attack is neat too.
.
Strobe-o-tach I think.


http://www.allaboutbatteries.com/Energy-tables.html


AAA Alkaline
Long-life      1150   milli-Amp
hours (mAh)   For instance

TinselKoala

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #103 on: May 30, 2014, 08:02:26 AM »
Strobe attack works for me...  ;)

synchro1

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Re: Selfcharging cap circuit from Larskro fake or real ?
« Reply #104 on: May 30, 2014, 11:18:29 AM »
Meanwhile, here's MiniPulse II, with bipolar transistor instead of mosfet, running down to the limit of the Hall sensor's switching at just under 2.4 volts. Runs well on supercap, makes spikes 3x input voltage but still no voltage climb effect. I can't find any reed switches in my stashbox....   :(

http://www.youtube.com/watch?v=gC5GiLVCUPM


@Tinselkoala,


There are several very good youtube videos on how to manufacture your own "Reed Switchs" at home. This is a worthwhile approach, mainly because the switch needs a hair trigger custom installed, and a self build allows one the freedom to experiment with tiny biasing magnets to get something real "Witchy" worked up!


The switch has to linger a little bit to carry the reverse fly back power home to source. You would need a complex arduino program and multiple componants, probably a second transistor, to even come close to matching the tiny switch time intervals the magnet levers allow one to create. It's the amount of time the switch stays closed, after activation, or the hysteresis loop that bridges the reverse return power. Maybe nano-seconds!