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

[conradelektro]

Hi Conrad,


Data sheet for your ALD MOSFETs says:

One more thing: you surely noticed the pins with asterisk symbol as (IC*) and these pins are also recommended to connect to V-  i.e. to the most negative voltage rail.  Such pins for the quad device ALD110800 are Pin 1, 8, 9 and 16 and for the dual device ALD110900 these are Pin 1 and 8.

You mentioned the Drain Source On resistance is 500 Ohm, however this is valid whenever the Gate Source voltage is +4V (at Vds=0.1V). And how well this condition is fulfilled in your shown oscillator circuit, an oscilloscope could be used to see the Gate source AC voltage waves with respect to the Source pin as being the most negative point.
OF course if you connect the dual device in parallel, then you would have about 250 Ohm RdsON and for the quad device this would be about 125 Ohm.

You also mentioned the internal diode between the Gate and the V- pins and it occured to me that while current can only circulate via this internal diode and via the 100 turns coil and via the LED when the induced AC voltage polarity across the 100 turn coil corresponds to the forward direction of both the LED and the internal diode (this is why the LED direction is important) so IN CASE the internal diode is a normal Si diode (albeit a very fast one) the forward voltage drop across it may be at least 0.6V and this lowers the useful voltage that may feed the LED from the total induced AC voltage peak so I wonder if connecting a Germanium or Schottky diode across the Gate Source pins in parallel with the internal diode (anode to anode and cathode to cathode) you may be able to gain some more brightness from the LED. Maybe this extra diode influences oscillation too much and you get just a dimmer LED, well I hope not... and if you agree and feel like testing it, please do. Even another Si diode like 1N914 or 1N4148 might be worth trying if you do not have any Germanium or Schottky diode at hand.

rgds,  Gyula

@Gyula: thank you for the helpful advice.

I connected a 1N5711 diode (forward Voltage 0.38 V)  from Gate to negative rail (in parallel to the internal diode) and it made the LED a little brighter at very low Voltages. I now see the LED glowing at 180 mV (before it was 200 mV). Starting at 250 mV the difference in brightness is clearly visible.

Connecting the IC* pins to negative rail did not change anything. I guess because they are internally connected to the V- pin which I already had connected to negative rail, it might reduce noise.

I use the two transistors in the in ALD110900 in parallel and I will try all four transistors in a ALD110800 in parallel. I agree, the V+ pin will be important in a ALD110800. I think V+ and V- get rid of stray charges in the component.

Just now I am preparing the winding of a 500 turn Slayer Tower. The winding is about 120 mm high, 30 mm diameter, plastic tube, 0.22 mm diameter enamelled wire. The primary will have 12 turns because that worked well with Slayer Towers I tested some years ago.

I am a big fan of the Slayer Exciter because it reminds me of a Tesla Coil. For me the Slayer Exciter is a Tesla Coil built with modern components (transistor instead of a spark gap).

At 1 V supply voltage a LED could be lit from the top wire of the 100 turns coil with an Avramenko plug (without connecting it to negative rail). So, it is a genuine Slayer Exciter.

Greetings, Conrad

[magpwr]

Hi Conradelektro,

I just placed order on ALD110800 last night.I could only advise any finding once i received those.

My plan  would be using 3 tap/output from toroid somewhat similar connection to get negative for mosfet  http://www.arrl.org/files/file/Technology/tis/info/pdf/culter.pdf
I would like to imagine that as a unique osillator or s/w radio base on above link using no (antenna or ground or battery).

Honestly 500ohms from single mosfet doesn't sound good even combining 4 mosfet to lower on resistance(RDS) to 125Ohms at around 5v.
The reason being 4 turns or 10 turns on primary winding of toroid would have resistance below "1" Ohms .
This itself create a huge instances of Impedance mismatch  between mosfet and coil which would lower efficiency further.

The only other way i know to increase Joule thief "current output" at around 50mV input is to connect good npn transistor ZTX1048A(22Ohms ... 100Ohms to base from secondary coil) in parallel  with one 2SK170(1.8k to gate from secondary like the original layout in 25mV joule  thief).Hint "The JFET will kick start npn transistor through emitter & collector once input voltage reach around 30mV(lowest possible osc to sustain for npn transistor ZTX1048A)    ...40mV"
This is tested to be working great at higher current draw depending on resistor value on npn transistor base which you need to tally with "source of power/current capability at 50mV".
These circuit is my version 2.0 using 50farad ultra cap quick charged in 1...3sec to get around 50mV which i have not posted yet.The reason why i have not posted ver 2.0 is because peltier measured output using body heat is only 4.2mA.

I will update finding about copper pipes/tubes with torrid once i purchased small copper pipes normally used in Air-con.

info only related to diodes-
1N5817 at 1A is 450mV  (Datasheet)     (Using multimeter to test forward voltage on my available Schottky diode 1N5817 is 0.145v)
1N5711 at 0.6mA is at 0.2volts (Looking at graph in datasheet) .I do not have this diode to test on multimeter  mode-Diode Tester

[conradelektro]

Some more tests with the Slayer Exciter using ALD110900 transistor:

The new coil (see photo) was not better than the toroid from my Reply #63. The Ferrite Core was necessary, without it at least a 1 Volt supply Voltage was needed. I tried many coil ratios from 8:500 to 25:500, 13:500 was best.

The lower limit to make the LED glow was still 180 mV and I have the impression that the LED was a little brighter with the Toroid.

I will change the ratio of windings on the toroid from 4:100 to 4:200 with a few taps to see if that leads further.

So, the 2SK170 is still the best for low Voltages, do not buy the ALDs yet.

I will try the Slayer Exciter type circuit with the 2SK170 and other Joule Thief variants with the ALD110900 and ALD110800.

Greetings, Conrad

[conradelektro]

Some more tests with the ALD110900 transistor:

See the attached drawing which shows all the tets I did with the ALD110900 transistor (2 transistors in parallel). Only the "Slayer Exciter" variant comes close to the 2SK170 transistor (180 mV), all other circuits need at least 700 mV. The toroid was better than an air coil.

One can make a JT with the ALD110900, two windings on a toroid and a LED, the electrolytic capacitor and the 1N5711 diode being optional. And it uses very little current, namely about 1.2 mA at 1 Volt or 1.5 Volt, although the LED is fairly bright at this level.

I now leave the ALDs be till I get new ideas and will concentrate on the 2SK170 transistor which could make a LED glow at 50 mV with magpwr's circuit.

What are the essential characteristics of the 2SK170? I want to find replacements, because it seems odd that only the 2SK170 can make a LED glow at 50 mV?

Greetings, Conrad

[magpwr]

hi conradelektro,

This is a huge list of N-channel Junction FET which will self osc\start at low voltage.But 2SK170 is the best over all.
I have already taken the trouble find out the best self starting component.Please note those i put those *high current out* are the better ones notably 2SK..series as listed below.Some 2sk jfet don't work so i exclude those and rest of unwantd JFETS already.

Please look no further unless it some JFET which is released recently,unknown at this moment.

N channel JFET which could self start at low voltage <100mV-----------

2N4861A      *35mv startup
2N4393   *    *60mv startup
2N3972           *33mv startup    ***********Could self start at 22mV (or 1mV lower than 2SK170)but much lower current output capability.
2SK117              *31mv startup -high current output
2SK170      *30mv startup -high current output ******final testing reveal this is the best self starting at 23mV.
2SK364               *31mv startup -high current output
2SK366               *31mv startup -high current output

2N4093       *35mv startup
2N4223               *35mv startup
2N5484               *60mV startup
2N5103               *60mv startup

BF510                 *45mv startup
BF410B               *60mv

BC264C               *60mV
BC264A               *60mV
BC264D               *60mV