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

[magpwr]

Hi Conradelektro and TinselKoala,

To conradelektro,
You asked At what Voltage does the ZTX1048A transistor self start in your circuit?
The answer i only get oscillation to start(temp shorting emitter & collector) 60mV which i was comparing against the old Japanese transistor 2SD1450.I could manually get oscillation to start at 50mV.
But my objective was to see how low voltage a good transistor could continue to oscillate base on low vce(found in datasheet for lower current draw <200mA)
The improvement i noted is oscillation lasted as low as 30mV for ZTX1048A compared to Japanese transistor 2SD1450(Oscillation stop around 43mV) which had slightly higher VCE drop.
If you checked out my youtube channel search "Sanjev21" title would be "Ultra Low voltage 45mV Joule Thief -Potential to be powered by peltier using body heat only" .This was 1st original non self starting version joule thief using the Japanese transistor.I have not posted ZTX version video since by then i had received the 2SK170 to work with.

Please try not to think about "neutrino detector" just typing this word in google yield huge collection of image all of which are built deep underground.I mean to say it's huge.
Seen a documentary about capturing 1 or 2 neutrinos which orignates from the sun years ago just to study it.Can't recall fully.

To TinselKoala,

Thanks  for providing interesting links which makes our eyes open even wider.
But i'm more interested in this particular link you sent.
http://www.arrl.org/files/file/Technology/tis/info/pdf/culter.pdf

The author mentioned-
It only takes 5 to 10 mV peak-to-peak on the
source of the MOSFET to provide an adequate
volume level.

There is a another line in pdf where he mentioned combining 4 mosfet to improve performance-
The detector consists of four MOSFETs
in parallel using the quad version of the
detector IC in order to better match the lower
resonator impedance

AL D110800A  (Dual Mosfet version) 
ALD110800APCL(Quad mosfet version)

I will reading up the datasheet to check to current draw capability.Who knows it might be even better than 2SK170 ultra low 25mV.

Lastly,

There is another plan that popped in my mind.How about we use "motor as micro power generator through vibration" as we walk.This idea would be better than peltier since
voltage output could be around 500mV to 1v around 10x times better in terms of voltage output for joule thief.

This is sketchy plan in words as from my mind.Use a small palm size rectangular plastic box as the housing unit for "motor used as micro power generator".
The motor will be the weight on the center and motor is connected to 2 springs(One on the upper portion of the box) and another spring from motor to lower half of box.
The "motor needs to be dual long shaft type" with gears on both end of motor shaft.In the box a line of teeth(From top to bottom) to be lined both side of box(Have not figured out how to balance motor parallely).

If we place the rectangular box vertically in our bag then as we walk the motor would vibrate up and down therefore generating good amount of electricity "on the move".
In theory the power output would be at least 10x time better than peltier design.To power joule thief.

Just a concept.

[conradelektro]

There is a another line in pdf where he mentioned combining4 mosfetto improve performance-
The detector consists of four MOSFETs
in parallel using the quad version of the
detector IC in order to better match the lower
resonator impedance

AL D110800A (Dual Mosfet version) 
ALD110800APCL (Quad mosfet version)

@magpwr:  I ordered some Quad ALD110800 and Dual ALD110900 transistors. Mouser rips me off for them (about EUR 3.-- a piece and specially the delivery costs are remarkable), but these transistors just sound right for extreme low power applications. This fascinates me at the moment. Thank you magpwr for sharing your findings.

Interesting is also the use of more than one transistor in parallel. That seems to be less exotic than I thought.

Once I have a very low power Joule Thief working I also have to carefully select the LED. Some LEDs are brighter at low power. Conventional wisdom suggests red LEDs, but the white LEDs have become rather bright at low power. And at the specified power (e.g. 20 mA) they almost hurt the eye.

There is also much work to do with the coils. I guess one wants high grade Ferrite toroids (high induction) and that the oscillation frequency will be low with low power sources. But the 4 : 100 ration suggested by magpwr is a very good starting point.  I tried to measure frequency at my test circuit (2N3904 transistor) at 0.15 Volt, but the DMM influenced the circuit and I did not get a meaningful result. One has to do it "indirectly", but at low power everything one does will influence the circuit (e.g. a measurement winding over the toroid).

I also saw that one can put away the resistor at the base at very low Voltages (e.g. less than 0.2 Volt). That makes the LED brighter. Specially with very low power sources that becomes an option. The transistor will be completely unprotected, therefore one has to be careful that the power source does not increase over a certain threshold (as could happen with a Peltier Element) or it will burn the transistor.

Greetings, Conrad

P-S.: I never thought about a conventional Neutrino tank in my basement, I am looking for a strange field or material that interacts better with neutrinos than the liquid in the big conventional tanks. But it is only a wild thought experiment and not a serious project.

[magpwr]

To conradelektro,

It is a good idea to start working on toroid while waiting for parts to be delivered.

Smaller toroid will work just as efficient as well base on my findings.But it's bit more challenging on the mind to wind the toroid.I used a small hard plastic which could pass through the small toroid.
A deep V is cut on plastic on top and bottom to hold the copper wires.The length of plastic is around 1/2 index finger to hold copper wire.Someone in youtube even used ice-cream stick with V cutting to wind toroid.

Another findings related to toroid big or small if your secondary winding exceed the 1/2 way mark\circle\toroid i noticed the efficiency drops.Keep it within the 1/2 as shown in my 25mV Joule Thief video.

[TinselKoala]

The "someone" may have been me, as I posted such a video. I was surprised to learn that people were not already using this method. The length of the spindle or bobbin (i'm not sure what to call it) should be slightly more than one full wrap of the wire around the toroid. Then you can estimate the amount of wire to wrap onto the spindle by the desired turn count on the toroid very easily. Use a material that won't scratch off the enamel insulation; I have used wood and scraps of circuit board material. I've also used aluminum but this can scratch the insulation, if the spindle is wide enough to contact the already-wrapped wire as you push it thru the hole in the toroid.
Another way to do it is to make a splittable circular form that you can assemble onto the toroid through the hole in the toroid. Then you wind your wire from the supply spool onto the circular form,  and then off the circular form onto the toroid.

[conradelektro]

Update:

I got some 2SK170 transistors and my replication of magpwr's circuit works down to 50 mV. It seems to draw about 0.5 mA at 50 mV.

And it is self starting all the way down to 50 mV. The white LED glows dimmly at 50 mV.

At 100 mV the LED is fairly bright and the current draw seems to be near 1 mA.

The resistor at the Gate is 2.2 KOhm, just one transistor and my coils on a toroid are 10 : 100 at the moment (just to try out some ratios).

I have to take of a few turns to get to 4:100 and will report more tests soon. With four transistors and a ration of 4:100 it should go down to the 25 mV reported by magpwr.

The 50 mV are the lowest supply Voltage I have ever seen for a Joule Thief on my workbench. Thank you magpwr for finding and disclosing the 2SK170.

Greetings, Conrad