Smoothest, and best, store purchased Joule Thief I have seen yet.

[TinselKoala]

And... here's the data sheet for it. Up there, I mean.

[Legalizeshemp420]

And... here's the data sheet for it. Up there, I mean.

Yep, I knew it was Schottky barrier diode but all parts listed in the parts list are what is on this board (Q1/Q2 were changed in the simulator because S9013 is not available).

[Pirate88179]

The black blob covers the chip.
There are more than two connections to the chip, I believe, two traces visible on the foil side connecting components and two solder blobs connecting wires.
The green resistor-like thing on the component side is an inductor.

I think this is essentially the same circuit as the one posted above with the ANA608 chip, which is tiny, barely room for the four leads. A smd version would easily fit under the blob.

Thanks TK.  I had no idea there was an IC that would run on 1/2 volt, which is about what these run down to before the lights go out.  If this chip will do this I should make a JT with one of my own coils.  I have stayed away from using chips because most of them need like 5 volts to run.  (555's, etc)  Why did they enclose the chip in that blob?

Bill

***EDIT***

LH  Thank you for pointing out the same thing.  I had no idea that green resistor looking thing was an inductor.  I have several of those in my resistor collection box from electronics that I have salvaged parts from.  I guess I need to place them in another bin.

[Legalizeshemp420]

Over the last 30 years whenever I opened up a China, or Japanese, cheap electronics item I almost always found that blob.  Back in the day (circa early to mid 80's) if it had a piezo speaker it always had that blob.  That blob always ended my exploration because there is nothing we can do with it.

What is ironic is that these chips can be ran on such a low voltage.  Look at my video where I show a square wave that makes the solar powered figures dance.  That is no battery and at less than half a volt.  Only discrete part on it is a 10v 470uf 105c Electrolytic capacitor.  The black blob has 4 connections.  2 for the solar panel (.5v) that has the cap in parallel with it and two going to the pancake coil.  It makes a wonderful square wave pulse that the time, and amplitude, is dependent upon the voltage it receives but it is always a clean square wave.

[TinselKoala]

Yep, the chip is a little low-power square-wave oscillator.
Which gives me an idea. A friend of mine gave me a bunch of these:
http://www.surplus-electronics-sales.com/index.php?main_page=product_info&cPath=38&products_id=589
They need a 5v supply but make a very nice accurate and clean square wave output.