Lasersaber strikes again. A joule thief king ?

[d3x0r]

Lasersaber update:

(prototype for sale http://www.ebay.com/itm/321441926223?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649&autorefresh=true  only hours into it and already up from $25 base to $51)

https://www.youtube.com/watch?v=l5oh4y83mZU

https://www.youtube.com/watch?v=pDH4ahCBCAs  (almost 2 minutes per second charging with hand crank... 3 seconds = 5-6 minutes run )


LEDs
http://www.digikey.com/product-search/en?WT.z_header=search_go&lang=en&site=us&keywords=VAOL-10GWY4-ND&x=0&y=0&formaction=on
$0.373


pot core
http://www.mouser.com/Search/ProductDetail.aspx?R=5678181221virtualkey62300000virtualkey623-5678181221
$0.681
( 2 layers, power-collector, 4 layers power-base)


coil former
http://www.mouser.com/Search/ProductDetail.aspx?R=B65652B0000T001virtualkey59250000virtualkey871-B65652B0000T001
$0.61


mpsa18
aluminum electrolyte cap

[TinselKoala]

That's really cool! I hope he makes some money. The 3d printing is really nice.

Those pot cores are tiny!


Meanwhile, in my loopstick variant I have found a  "new low" transistor. It starts at 0.425 V and stops at 0.100 volts (LEDS just out, but still oscillating.) Finally stops completely at about 0.089 V.

I don't know what the transistor is, though! It is a TO-92 plastic case, marked

1802
N711
EBC

and has a tiny M in a circle on the back (rounded) surface.

Nice of them to give the pinout anyway. Does anyone know what this transistor is? I've done the usual googling and can't identify it.

[mscoffman]

That's really cool! I hope he makes some money. The 3d printing is really nice.

Those pot cores are tiny!


Meanwhile, in my loopstick variant I have found a  "new low" transistor. It starts at 0.425 V and stops at 0.100 volts (LEDS just out, but still oscillating.) Finally stops completely at about 0.089 V.

I don't know what the transistor is, though! It is a TO-92 plastic case, marked

1802
N711
EBC

and has a tiny M in a circle on the back (rounded) surface.

Nice of them to give the pinout anyway. Does anyone know what this transistor is? I've done the usual googling and can't identify it.

@TK

Try 2n711 -  Link;

http://alltransistors.com/transistor.php?transistor=6184

look at the small .pdf file   Small Signal   Germanium *PNP*   *min. ce = -0.5Volts*    Shows a metal TO-18 package
but that could change. They often left the "2N" just so they can mark the tiny package.

[TinselKoala]

@TK

Try 2n711 -  Link;

http://alltransistors.com/transistor.php?transistor=6184

look at the small .pdf file   Small Signal   Germanium *PNP*   *min. ce = -0.5Volts*    Shows a metal TO-18 package
but that could change. They often left the "2N" just so they can mark the tiny package.

No, I don't think that's it, but thanks for looking. The circuit won't work with a PNP, I think, and the behaviour with this transistor is just the same as with the others, it just has slightly different start and stop voltages. It must be NPN and I doubt if it is germanium.

I tried several FETs, just to see if they would work in the circuit without modification.
NTE451, MPF102, 2n5613, none worked.

Also tried 2n3704, which gave start at 0.434 V and stop at 0.109 V.

2n2369a allowed charging to over 0.5 V and needed to be tickled into oscillation, and stopped at around 0.230 V, so not a good performer in this circuit.

ECG123A didn't work at all, which puzzles me.

Another oddball marking: 9287 N710 EBC gives start 0.436 V and stop at 0.103 V.
Another: 200-32 F340 gave start 0.427 V and stop 0.127 V

2n2219 start 0.434 V stop 0.142 V
2n2219a start 0.417 V stop 0.134 V

The only germanium transistor I have in stock is 2n2635 / NTE160, which is PNP and doesn't work.

[conradelektro]

Extreme prototyping:

I kind of replicated Lasersaber's 3D-printed-torch (https://www.youtube.com/watch?v=pDH4ahCBCAs).

It is not 3D-printed, not portable, has a different coil and the three white LEDs give a fairly bright light for about 3 minutes for three turns of the hand crank.

I showed my SJRLooper circuit and the coil here:
http://www.overunity.com/14591/lasersaber-strikes-again-a-joule-thief-king/msg406322/#msg406322
http://www.overunity.com/14591/lasersaber-strikes-again-a-joule-thief-king/msg406424/#msg406424
(the resistor is 1 M instead of 20 M to make the three white LEDs shine brighter)

My hand cranked stepper motor charges the caps till the Voltage reaches about 15 Volt, then the red LED starts to light up and to syphon off the charge. The red LED indicates that one can stop cranking. Three turns of the crank are enough to charge 5700 µF to about 15 Volt. Then the three white LEDs shine nicely for about 3 to 4 minutes. It takes about 7 minutes till the three white LEDs are completely off.

My replication is just an experiment, not really useful.

Some time ago I made a video about my hand cranked stepper motor generator http://www.youtube.com/watch?v=qec_qsDseCY .

Greetings, Conrad