P.S: I have the same circuit as this now:
http://www.overunity.com/6123/jule-thief/dlattach/attach/117923/

but I have a 25 K linear Pot instead of the 10 K Pot and instead of the power supply
I have a 15.000 uF cap and I also have a 5.6 K resistor going from the mid tap of the pot to
the base.

Instead of the 2N2222 I have a BD 139 and instead of the 2N3055 I have a MJE1100.

I also have a transformer with Metglas or iron tape core ( don´t know, bought cheaply
from an electronics store...)
with the primary having about 15 turns and the secondary having 100 turns.
I have a 230 Volts AC 3 Watts LED bulb.

Hope this helps.

Regards, Stefan.

Hi GL,
is the upper left picture a top view or a bottom view ?

Yes, that was the problem with the MJE1100 datasheet !

Now I have got a MJE1100 and a BD139 connected as a new
Darlington pair and got my LED bulb running on the cap,
but I don´t get this blinking effect.

I can only get it to light up , when I permantly connect the 12 Volts supply via my 15000 uF cap.

Still have a 25 K pot across this cap and a 5.6 KOhm resistor going to the base of the new darlington
to tune the base potential....

ALso I don´t know, where Laserhacker put his graetz bridge to...


Have to leave the house now.... Will experiment tommorow further on,
when we know, where Laserhacker did connect his rectifier bridge...

Regards, Stefan.

Stefan,

Normally all data sheets display the transistor top view.

GL.

Wow.... I fell behind there, got a lot of catching up to do, I can tell..... but meanwhile....

@GL: If you want more output voltage you need more inductance I think. The total inductance of both coils (or coil segments) is the key, I think. The voltage spikes on the output come from the collapse of the field in the inductor(s), so you get more voltage in two ways: increase current for more field -- this is done by raising the input voltage, not what we want necessarily, or increase inductance for more field in the inductor, by adding windings or using different core materials.
If both coils are wound on a single core like most of us are using (but not Sohei Thoth, very nice work there) then changing the core will affect both coils, obviously, or the inductances can be varied separately by varying the number of turns.
My best HVJT uses a 10mH inductor from an old TV set, looks like about 300 turns on a cylinder of good ferrite, and I wound 30 turns of heavier wire on top of that for a "primary". It makes well over 600 volts no-load on a "dead" AAA input,  and can charge up external caps very quickly thru a diode rectifier.
I have not yet sorted whether or not it is the primary inductance or the secondary inductance separately that is more important for HV.

OK, back to catching up.....

TK,

I understand what you are saying. That was also my conclusion.
But there is more to this circuit. I recommend that you build it and test it.
It is a fun circuit to play with and probably a very useful circuit when we want
to power LED lamps from batteries. I did try some ceramic capacitors over
the output and the light in the LED bulb did increase. Also the LED brightness
goes down when I connect an antenna to the collector of the power NPN.
Need to test more on this later on.

GL.

RE mosfets: they switch by charge (voltage) not base-emitter current like bipolar transistors. Most mosfets need at least 4 volts (but negligible current) on the gate to begin to turn on and 6 or more for solid turnon (logic level can switch fully with 5 volts on gate), and are easily damaged by HV (read 20 volts over the Source pin voltage) spikes to the gate. This means that they are not going to work as the primary transistor in a JT, I think. However it might be possible to use a mosfet, with a little fiddling with resistors, as the second, driven transistor in the 2-transistor designs above. I am going to have to confirm both these results experimentally, but that's what I'm thinking now.
My LED ring oscillator uses 2n7000 mosfets and sometimes acts strangely when I drive it with the JT but I haven't failed any of its mosfets yet. The 2n7000 is a great little mini-mosfet, it's the "2n2222" of the mosfet world. Since these are so cheap (about a dollar or less each) I'd suggest trying one of them first in a hybrid design, driven by the 2n2222 or 2n3904.
The body diode is a result of the manufacturing process; not all mosfet  _symbols_ show it -- most 2n7000 symbols don't-- but it's there to some degree in all mosfets I know about including the 7000.

TK,

I understand what you are saying. That was also my conclusion.
But there is more to this circuit. I recommend that you build it and test it.
It is a fun circuit to play with and probably a very useful circuit when we want
to power LED lamps from batteries. I did try some ceramic capacitors over
the output and the light in the LED bulb did increase. Also the LED brightness
goes down when I connect an antenna to the collector of the power NPN.
Need to test more on this later on.

GL.

That is my plan for the evening, after dinner. I just discovered that I have a 2sd2539 that I pulled from an old TV set, also a 2sd870, plenty of 2n2222s and 3904s, even some 2n4234 and TIP42 PNPs,  and I have a box full of all kinds of mosfets. What I don't have is one of the 3 Watt, line-powered LED bulbs.

Does anyone know the power supply circuitry inside these mains-powered LED bulbs? Is there a schematic I could look at somewhere?

Thank you Wings!!

FWIW, here's my 10mH JT lighting 4 x 90 Volt NE-2 neons in series, running on one depleted AAA battery at 0.93 volts.

There was just posted a circuit diagramm here:

http://laserhacker.com/forum/index.php?topic=70.msg634#msg634


I copy it here also for all to see directly here:

Stephan i am up and running with the diagram posted and corrected by ground loop .The collectors are NOT connected together  and the above diagram looks wrong .. .. WOW . i don't think it can be measured correctly with digital meters . I am using his exact cap with a 5 volt lipo . I am lighting a 220 volt led bulb with just one wire . This circuit even untuned draws nothing and appears to charge up more than you start with ..

the reason i say it can't be measured is because with the meter across the cap with the circuit off i read 4.98 vdc with it on it increases to now 5.03 . also i am using his Ecore . it it brighter with the ferrite out of it . AIR CORE  Cool circuit .

Mine is wound with about 3000 turns secondary and 15 turns primary but i have not got it to resonate on the cap alone . I have got shocked with the battery disconnected and see the led bulb flickers when i move the ecore in and out .


Where is Tk he need to try this . This IS wILD

EDIT . Oh . pay to refresh TK NICE !!!! . hey if you get a chance try the circuit ground loop posted of laster sabers . it is VERY Interesting . Why would a battery go up in voltage on his circuit . Im scared  one wire too ...

dare i say it >1 .. I am uploading my experiment . Please excuse the mess and whittlings on the bench . i need to cleaan it . I think this is a very nice low power circuit .Also it will run from a 1.5 volts . I need to wind the primary until it starts everytime..


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