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Author Topic: Lasersaber strikes again. A joule thief king ?  (Read 412311 times)

conradelektro

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #225 on: June 13, 2014, 02:04:40 PM »
LTSpice screencapture

@Collapsingfield: thank you, I will try to add these caps. The aim is to bring the circuit to oscillation without the resistor between base (of transistor) and positive rail. So far I need a MPSA18 and a very special coil. I hope the caps will do the trick because I hate winding many different coils.

Greetings, Conrad

TinselKoala

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #226 on: June 13, 2014, 03:14:57 PM »
More on burst oscillations and using the DSO to examine the waveforms:

http://www.youtube.com/watch?v=9FDmkbCbKP0


@conrad: Yes, getting to the point where you can eliminate the resistor is a noble goal. Resistive elements just waste "light" power by I2R joule heating. If you insist on starting out with high voltages, the base current of the transistor needs to be limited somehow. The resistor is one wasteful way. Another way is to "tune" the spike or oscillation frequency so that the transistor is only on for a tiny time, and using no base resistor.  But that method isn't compatible with this circuit because you just can't get the spike frequency high enough or short enough, especially using "cliplead" construction. The RC trick instead of just R for the base drive helps.
Then when you are making really fast short spikes, you encounter the high voltage problem: the transistors we are using can't handle the inductive collapse voltage amplitude.

Try the NPN transistors found in some CFLs: I have one here marked "W6L 13003" that works really well for short, highfrequency spikes and it can take the voltage. (Many CFLs use mosfets instead of the NPNs ... I think I got these NPN transistors from a lower-wattage CFL).

MladenStijepic

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #227 on: June 13, 2014, 03:40:35 PM »
"W6L 13003" is mje13003, it is actualy whole range of mje13003 to 13009 ,they differ in volts and amps,mje13007 is common in atx power supply.

Had to say this, this is actualy my first post here, greets to all!

d3x0r

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #228 on: June 13, 2014, 04:10:44 PM »
More on burst oscillations and using the DSO to examine the waveforms:

http://www.youtube.com/watch?v=9FDmkbCbKP0


@conrad: Yes, getting to the point where you can eliminate the resistor is a noble goal. Resistive elements just waste "light" power by I2R joule heating. If you insist on starting out with high voltages, the base current of the transistor needs to be limited somehow. The resistor is one wasteful way. Another way is to "tune" the spike or oscillation frequency so that the transistor is only on for a tiny time, and using no base resistor.  But that method isn't compatible with this circuit because you just can't get the spike frequency high enough or short enough, especially using "cliplead" construction. The RC trick instead of just R for the base drive helps.
Then when you are making really fast short spikes, you encounter the high voltage problem: the transistors we are using can't handle the inductive collapse voltage amplitude.

Try the NPN transistors found in some CFLs: I have one here marked "W6L 13003" that works really well for short, highfrequency spikes and it can take the voltage. (Many CFLs use mosfets instead of the NPNs ... I think I got these NPN transistors from a lower-wattage CFL).


The resistor I find is useful to start it sometimes ... some coils are better than others; the one with the foils starts almost every time (capacitance of foils) ...
I find that putting a diode from the base to the negative (so when the base is extra-low it gates to ground) helps it start up more reliably, and run at slightly higher output


I don't get a sharp high pulse on the gate(err base), it's always a low pulse...
one coil I have is like 2mH and 20mH, and can get out very high voltage on the collector side but the runtime isn't notable.

conradelektro

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #229 on: June 13, 2014, 04:11:06 PM »
@Tinselkoala: thanks for the scope lesson, I had a vague idea about the "single shot" feature but your video brought it to the point of understanding.

I am not insisting on higher Voltage, the JSR Looper circuit I showed last also works down to about 1.5 Volt (scope shots are similar to what I showed at 9 Volt) but the two LEDs are then just glowing (which can be remedied by a 1M resistor instead of the 20M resistor between base of transistor and positive rail).

A reason for higher Voltages (9V or 12V) might be the step down arrangement in Lasersaber's JSR Looper V3.0 which I could not yet replicate in a consistent way.

Also a "magnet shaker" might produce spikes up to 20 Volt which could be collected in an electrolytic cap to drive the JSR Looper circuit.

But still, it will be easier to produce low Voltage (0.5V to 1.5V) with alternative means, therefore a low Voltage circuit has an advantage.

So far, by all these Joule Thief variants, I was most impressed by the 2SK170 circuit that works down to 50 mV
http://www.overunity.com/13175/25mv-joule-thief-powered-by-peltier-merely-using-our-body-heat-free-energy-247/msg382567/#msg382567 (from magpwr).

Greetings, Conrad

d3x0r

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #230 on: June 13, 2014, 04:20:00 PM »
I did have a setup that had a mode that was a touch-sensor... very reliably; used a tiny inductance coil (24 turns 1" mobius) , and touching the coil on the low side of the LEDs (opposite the base) would make it turn on very brightly.  very very reproducably.  Often I end up using my body as the Megohm resistor for starting (toughing power and other points on the circuit) but this was just me touching it; and I was fairly not grounded.... thought about filming it; but I doubt it's reproducable effect

MarkE

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #231 on: June 13, 2014, 05:05:13 PM »
I did have a setup that had a mode that was a touch-sensor... very reliably; used a tiny inductance coil (24 turns 1" mobius) , and touching the coil on the low side of the LEDs (opposite the base) would make it turn on very brightly.  very very reproducably.  Often I end up using my body as the Megohm resistor for starting (toughing power and other points on the circuit) but this was just me touching it; and I was fairly not grounded.... thought about filming it; but I doubt it's reproducable effect
Sounds like capacitance.

TinselKoala

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #232 on: June 13, 2014, 11:03:44 PM »
Yes, capacitance. I've got them that do this too. Even this present circuit will do it when properly tuned.

I can't find 2sk170 locally and I keep forgetting to order them.



Meanwhile, more on burst oscillations, or rather oscillation bursts. There are at least three different oscillations happening here.



Preva

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #233 on: June 16, 2014, 07:09:19 PM »
И снова ЗДРАВСТВУЙТЕ!
Сделал схему не на броневом сердечнике, а на феррите от строчного трансформатора. Вот, что получилось


http://youtu.be/iTVlVBkm_CA


Интересно, что трансформатор работает как с ферритом, так и без него.


И до сих пор не могу добиться работы схемы Lasersaber более 10 минут с конденсатором 4700 мФ







And again HELLO!
I made the scheme not on the armored core, and on ferrite from the lower case transformer. Here that turned out


http://youtu.be/iTVlVBkm_CA


It is interesting that the transformer works both with ferriy, and without it.


Also I can't still achieve work of the scheme of Lasersaber more than 10 min. with 4700 mF

a.king21

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #234 on: June 17, 2014, 05:07:45 AM »
Preva:  you need to use exactly the same transistor. Other transistors won't work.

TheCell

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #235 on: June 17, 2014, 01:17:20 PM »
Гт 402 А германиевые (Germanium Transistor)
http://lampilich.narod.ru/tr/small/gt402.html
Any western equivalent?


TinselKoala

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #236 on: June 17, 2014, 08:12:18 PM »
perhaps
NTE101
NTE103
?


broandrew

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The joule thief "the cell" is now in jail!
« Reply #237 on: June 18, 2014, 03:44:09 AM »
This guy Robert Potchen, thecell.com crook, is now in jail.

Go see for yourself :

http://www.wftv.com/news/news/local/good-samaritan-rescues-woman-being-beaten-husband-/ngMYY/

He ripped a bunch of us off and many more with his hydrogen cells that DO NOT WORK, he produces tons of para-hydrogen and leans the trucks with EFIE electronics, no gains from the hydrogen. Para hydrogen only pre detonates the engine and fights the combustion. You get worse mileage. He offers a warranty and you never will get your money back, ever.

TinselKoala

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #238 on: June 20, 2014, 07:17:20 AM »
Here's an interesting effect I just discovered using my SooperLooper variant of the LaserSaber circuit. I think this is the lowest supply voltage I myself have attained with bright LEDs: at 0.2 volts the three series LEDs are still bright and they don't go out until 0.11 volts or so.

http://www.youtube.com/watch?v=yjgemF5zpeE

I'm using 2sc3198 in the video. With MPSA18 the LEDs are dimmer, the discharge rate a little slower (longer running) but the cutoff is up around 0.12 volts on the supply capacitor.

I made a couple of mistakes on the schematic. The transistor is 2sc3198, not "2sk", and the stock loopstick Litz winding is the one with the LEDs across it, not the one shown on the left of the schematic. Sorry about the confusion... it's all mine.

havuhung

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Re: Lasersaber strikes again. A joule thief king ?
« Reply #239 on: June 20, 2014, 08:03:32 AM »
Hi TinselKoala,
In your video clip, I saw had a ferrite core horizontal oscillations-holding television old. . .
Difficult I found, that can replace the coil with others? . . .

Thanks