Joule Thief

[jadaro2600]

@ Gary (resonanceman) and all other experimenters who have experience with a lot of different "cores", toroids or "transformers" in a Joule Thief circuit:

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I "see progress" with bigger diameter air coils (200 to 300 mm). The bigger coils show very nice regular patterns when swinging, not spikes like toroids or transformers.

Attached see one example with an 110 mm diameter air core. The big bumps are happening with 108 KHz.

When I put a 3 K resistor on the base (with a 1 Volt power source) I can create nice sine waves with several hundred KHz on a secondary L3, but the voltage stays very low (e.g. 60 Volt) in spite of the many turns of L3 (see second scope shot).

...

I've been looking for a setup which will light both sides of a neon; then it appears as though an air-cored coil setup would be the way to go.

Does anyone else have any suggestions.

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I've been having trouble soldering the leads to these trigger coils I picked up.  What is the purpose of or difference between rosin core and common solder?  ..do I need to pick up some sort of etching or rosin?

[Pirate88179]

What little I know:

Rosin core is for electronics and stuff that should need to work for a long time.

Acid core is more for like plumbing, and not so sensitive stuff as it actually etches the surface. (eats) If you use this for electronics, somewhere down the road the circuit may fail due to corrosion.

Clean surfaces is always a good idea although I don't clean the copper wires like I do copper pipe before soldering.  The soldering flux does a nice job there.  Only mag wire do I clean after I burn off the plastic/varnish insulation.

Bill

[jadaro2600]

A couple of days ago I was in Office Depot and went to buy a drink from the checkout area and noticed a Clearance box with some Energizer hearing aid batteries in it, ...two Zinc Air #10 dispensers with eight batteries in each of them.

Rated at 1.4Volts, these look like an interesting source for any up coming micro-sized compact or other JTC circuits.  Pretty nice deal at 25 cents per package of 8.

I've been finding a lot of interesting things in the clearance sections lately... the walmart clearance sections ( often in the back of the store in the arts and crafts area or near sporting goods ) is usually has some interesting stuff in it.

I found some foam pads and felt/velvet/suade there for cheap ( plenty enough to re-line an old jewelry box ).

[dasimpson]

im still strugling to understand what you mean by inducter

[conradelektro]

@ jadaro2600

Here my findings so far concerning sine waves on a secondary L3 in a Joule Thief type circuit:

- use an air core with a diameter between 100 and 300 mm (I know this is big, but you then do not need that many turns for L3, may be 150 to 400 turns); 0.2 or 0.3 mm diameter enamelled wire; thinner wire is very difficult to handle and thicker wire needs a lot of space and more turns

- start with winding the secondary L3 on the cardboard or plastic tube; I put a strip of double sided sticky tape on the tube to hold the windings while I wind (with a primitive hand winding station I built)

- on one end of the secondary L3 you wind L1 + L2 over L3; either bifilar or center tapped (I put a piece of paper on L3 to protect it when winding L1 + L2 over it)

- use very few turns for L1 + L3 (may be 6 to 9)

- use an adjustable base resitore (0 to 10 K with a safety 100 Ohm) and set it to 2 to 4 K Ohm, the sine wave will have several hundred Kilo Hertz (I have seen 700 KHz, easily 400 KHz)

- the voltage of the sine wave on L3 will be rather low (may be 60 to 120 Volt); when you decrease the base resistor, the voltage over L3 will go up, the frequency will go down rapidly and the sine wave becomes more like spikes ringing down

- when you see sine waves on L3 the consumed power will be rather low (may be 40 to 100 mA) because the base resistor will be high (2 to 4 KOhm)

- what I said is for a 1 to 2 Volt power supply, if you use higher supply voltages (e.g. 6 Volt to 12 Volt) frequency will go down, voltage on L3 goes up fast, the sine wave becomes spikes and transistor and base resistor overheat within seconds


An experimenter calling himself slayer007 has an interesting circuit which I will explore soon (when I get bored with my air cores on the basic Joule Thief circuit):

http://www.youtube.com/watch?v=uU_HeCr8BTM (Slayer explains his circuit at the beginning of the video, therefore it is a video as I like them, because I can understand what Slayer is doing in the video)

But may be you also follow the thread http://www.overunity.com/index.php?topic=8977.45 GBluer (Slayer) Exiter.

What I would like is a modification of the latest Slayer circuit to avoid radiation. I want 1500 Volt to go by two wires into a CFL or neon with high frequency (may be 200 to 500 KHz, or even Mega Hertz). The wireless transmission of power is interesting but not yet for the average home.

From what I have seen, the basic Joule Thief circuit is very good for a 1 Volt power supply (a single or two AAA or AA batteries in series) but becomes critical (concerning overheating of the components) when using a power supply with higher voltage (4 Volt and higher, definitely with 12 Volt). Slayer has found I nice way with his adjustable capacitor to make a 12 to 18 Volt power supply possible. May be one can adapt this idea to the basic Joule Thief circuit.

A 12 Volt Battery charged by a solar panel with a high frequency Joule Thief type circuit lighting a CFL brightly could be useful. Some sort of emergency lamp or free energy lamp. The 12 Volt battery and the air core coil would be rather big, but for a stationary lamp that would not matter much.

I know, one can turn 12 Volt into 110 or 220 Volt with a commercially available converter, but that converter wastes power and is no fun (and it also "screeches" or "sings").

Greetings, Conrad