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

[Legalizeshemp420]

Here is the video with the waveform and all and I am really impressed by this little bugger.

www.youtube.com/watch?v=FbwzAmO0998

[Legalizeshemp420]

I was very busy today with my car but I did manage to squeeze in about an hour to reverse engineer the circuit.  Rather odd at one point as it makes no sense to me so I will run it up in the simulator and see what I get in a day or so.

[TinselKoala]

Your scope is showing a frequency of about 1.7 MHz.

I've taken apart a few garden lights myself. There are two main variants that I've found. One uses a photoresistor CdS as the ambient light sensor, to switch from charging in daylight to lighting the LED at night. The other simply uses the photovoltaic cell itself, both for sensing and charging.

The first type uses a tiny chip marked ZE002 and the second type uses ANA608. These are both four-terminal devices. Here are the schematics of the two types I've analyzed:

[Legalizeshemp420]

This is neither of those and has no IC on it (probably why it is better).  I already can tell it has a darkness sensor via the solar panel since I reverse engineered it I just haven't laid it out yet.  Works extremely well and I will take my DFC-1000 out to be 100% sure what the frequency is but I can't remember if it is a high impedance load or not.  I would hope it would be.

Oh, here is the parts count: 11...1 Diode, 3 Resistors, 1 cap, 2 transistors, 2 inductors, 1 Solar Panel, and 1 white led that I have no idea what the specs are for it.

[TinselKoala]

That's a lot of parts. What are the transistors? I would like to see the schematic when you have a chance. The DFC-1000 counter has a 1Meg input impedance for low frequency signals (Below 100 MHz), the JT won't even know it's there probably.

ETA: It appears to be the same as the Elenco F-1000:
http://electronicsandbooks.com/eab1/manual/Hardware/D/Dynatek/DFC1000%20c20060821%20%5B9%5D.pdf