25mV Joule Thief powered by peltier merely using our body heat -Free energy 24/7

[conradelektro]

@gyulasum:

I got this core http://at.farnell.com/ferroxcube/etd49-25-16-3c90/ferrite-core-half-etd49-3c90/dp/3056417?Ntt=3056417 (two halves, bobbin and clips). Would this be any good to wind the 5:500 coil onto? A bit big, but for a test size does not matter?

And I got this even bigger core: http://at.farnell.com/ferroxcube/etd59-31-22-3c90/ferrite-core-half-etd59-3c90/dp/3056430?Ntt=3056430

@magpwr:

I was not successful with the radio wave receivers (as a power source). But I might have done something wrong.

I tried the copper and aluminium tube very close together in the earth, no success. It works very well when the tubes are wrapped in paper soaked in salt water, but I do not want to throw a lot of salt into my garden. But I will try fertilizer around the tubes in spring.

I like my "magpwr circuit in Epoxy" (see the photo in my last post) very much (besides its odd shape). I used it submerge in water, no problem. I will buy some clear casting resin and make a few more for outdoor use.

Greetings, Conrad

[gyulasun]

Hi Conrad,

Yes, the smaller sized core ETD49/25/16 is already okay, no need for the higher sized one. And do make some taps on the secondary if you agree.  Your question on the core size: on a bigger core the coils will have higher inductance than on a smaller one (cross section area is higher), this means  the oscillator would operate at a lower frequency with the bigger core.  Your E cores are surely good from some Hz to at least 100 kHz or maybe higher (3C90 material) so you have a very wide range available, by tuning the secondary with some hundred pF or maybe 1nF capacitor in parallel with it.  On your smaller core the 500 turns will give L=N²*A_L=500*500*4.2uH=1050mH   i.e.  roughly 1 Henry inductance, this will resonate at about 22 kHz with a single 2SK170 JFET's gate-source input capacitance (nearly 50pF at 0.3V drain-source voltage from data sheet) if you do not use any other tuning capacitor. In case of 4 such FETs in parallel the frequency may go down to 11kHz or so.   (Of course these frequencies are rough estimates.)

Gyula

[gyulasun]

Hi magpwr,

I also disagree with patenting in general, however, design engineers with big ego tend to do so and boost with their patents, you know it  sound good for them...  LOL

Regarding the radio wave charging battery idea: problem is I think that even if you are lucky to collect a few Volts in a capacitor of some thousand microfarad (not in a supercap) it does need a certain time to collect it, and if you wish to charge ultra or super caps by radio waves, it may take days to have them filled up to a certain level unless you live near to a higher power transmitter. Crystal radio receivers have in general a high output impedance and a charging capacitor is definitely a low impedance device, albeit it demands an exponentially decreasing current from an initial high value when fully or nearly discharged. However there exists a so called step charge process when you insure the voltage difference between the charger output and the capacitor is always small and gradually increased in small steps so that no huge inrush current. This step charge method is also a long process though and the control circuit also needs some power to work from.
Regarding the Germanium diode rectifiers, you may replace them with syncronous MOSFET switches IF you already have an RF voltage of near 1 to 1.5V across a resonant LC tank circuit fed from an antenna. I mean syncronous rectifier as shown with the ALD MOSFEts in the Cutler.pdf in TinselKoala's link BUT use logic level MOSFEts instead of the ALD types, the logic level types can already open and conduct at 1V or 1.5V positive peak voltage on their gate with respect to their source.

It is unfortunate that in your country copper tubes are a problem to buy. On ebay here are some copper tubes with an outside diameter of

1/8 inch: http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1311.R6&_nkw=1%2F8+copper+tube&_sacat=0&_from=R40

3/8 inch http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1313&_nkw=copper+tube+3%2F8&_sacat=0&_from=R40
             http://www.ebay.com/itm/Copper-Coupling-For-3-8-O-D-Tubing-One-Coupling-/400298753167?pt=LH_DefaultDomain_0&hash=item5d33aa3c8f

1/2 inch http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1311.R9&_nkw=1%2F2+copper+tube&_sacat=0&_from=R40

Regards, Gyula

...
hi gyulasun,

Thanks for providing some interesting links.It does help us to promote creativity in each of us.I never knew people actually patent ultra low voltage voltage booster.
Good thing mine is unique and i will never patent my design especially for simple "electronics".It would be a waste of effort or time maybe money to patent.
---------
I would be planning to work on this project to compliment my 25mV joule thief.It's using radio wave to charge battery.I will be using it with ultra-caps.
http://www.youtube.com/watch?v=tjxldE8JsDw

I was active in this forum where there was discussion on the "RF diode charger" and etc.
http://laserhacker.com/forum/index.php?topic=104.0

I noticed it's very difficult to find antique items in my country like 1N34A that i have to order online from ebay.
I had problems even finding small copper tubes normally used in Air-con smaller version for copper tube\toroid transformer to experiment on resonance as i mentioned earlier in this forum.

[magpwr]

Hi gyulasum,

Thanks for providing links to copper pipes/tubes on ebay,this will be the last resort as the shipment cost base on weight of copper would be  high.
I will still continue with search for copper tubes in my tiny island-Singapore -50km(~35miles) wide.
There is potentially some businesses that sell copper tubes further away from my place.

It's frustating after buying toroids online base on specs as shown in this original video -double amazing joule thief 150leds on 1 AA battery,but simple copper tubes can't be obtained easily.
https://www.youtube.com/watch?v=blVqaiYv_WU

I had already purchased  zero threshold ALD MOSFEts(QUAD) for culter radio noticed in document which author which mentioned produces 0.125volts at output.
Even it fails to provide sufficient power to 25mv joule thief maybe on "interval basis" from charged capacitor,it would be used as radio as plan B.

[acmefixer]

I agree: much easier to wind.  Much more expensive, too, if you can get one the right size.  I've found a few in power supplies, but they usually require a lot of work to get them ready for winding.  If you're lucky you might find one that has the feedback winding already on the core.  Maybe with 200 or more turns on it.  Then it's easy to wind another few turns on the core for the primary.  I think if I want to spend the money on a core, I should just buy one that's already wound and ready for service.

Regarding taps...  I made it a lot easier to wind the toroid by just winding 50 turns of a manageable length of wire on at a time, then bringing it out and connecting it to another manageable length of wire, and on and on until I had 200 turns.  That's how it ended up in this picture (click on it multiple times).

Hi Conrad,

Thanks and may I suggest to make taps on the secondary coil at  1:50 and 1:75  turns ratio to make matching more flexible. Also, you could consider using ferrite pot cores or normal ferrite E cores instead of the toroid core shape, these latter cores are much easier to wind.

rgds, Gyula