Joule Thief

[xee2]

@ electricme

Photos look great. My interpretation of photo 799 (I assume that has the capacitor across the base resistor) is that the capacitor is slowing down the turn off of the transistor. Since the magnitude of the voltage spike is less when the rate of change of current is less, then this would produce a lower voltage spike. And since the amount of voltage induced in the pickup coil is also less with a slower rate of change of current, there will also be less voltage across the pickup coil. However, I do not see anything that would indicate why adding the capacitor across the base resistor decreases the battery drain (which is the reason I put a capacitor across the base resistor).

[electricme]

@Altrez

A very interesting thing I just discovered is that I can run a small DC motor from a pickup coil that on the second toroid with a diode bridge. This si the first time I have been able to run anything other then LEDS / NEONS and I am very excited.
Altrez

Yep, ME TOOO, I wanna see a photo if this is possible, could you discribe the winding secondary please.

I have a small tiny inci wincy electric motor, smallest I have eva seen, its the tail rotor in a electric powered helicopter, I think I will raid it and connect it to my JT and see what happens, he he.

OK see if you can find it

jim

0808.jpg = tiny electric tail rotor motor close up
0806.jpg = small chopper, I hid it in plane sight
0807.jpg = Now where is the small chopper?

I been in the garden also today, I burried a chunk of aluminium, upon testing, it comes up with nothing, zero, zilch, hmmmmmmmmmmmm. This is where I have my earth battery, plates of iron, lead, copper and carbon, now 2 choppers are in the mix.

jim

[xee2]

@ electricme

Thanks for taking all of the photos. Photo 801 does not make sense since the collector has to turn on and off at the same rate as the base. I think this oscillation is not present in the normal opperation of the JT but rather is caused by the scope probe interacting with the base. I think more data will have to be taken before the function of the base resistor capacitor can be understood. Photo 802 seems to match what I would expect in that it looks like the turn on of the transistor is being delayed.

[altrez]

@ Altrez

I'm sure it wont be long before you will become an expert with the Velloman scope, I saw an identical one in Jaycar when I was in Brisbane just 2 days ago, I'm very sure Jeanna will be able to teach you well in it's usage, well done Jeanna.

Al, many many many (I lost count) moons ago I was powering a huge 5 inch torid in a similar fashion as you are doing.
I used the secondary of the Joule Thief to power up the second torids primary, which it's secondary was rectified, fed into a cap and I managed to get a 12v DC fan to spin up but it would stop after a few seconds.
It seems you been able to get more energy out of your setup, well done.

I made a TinyWeinyVideo, and posted it here on this forum, so I can understand you being "excited" at your success, Bill's a bit excited isn't he he he, don't think he will get quality sleep tonight as he has found out what his cro can do now.

I still have my original setup, I will post a photo of it so you can compare it to yours.

@ Gadget,
Thanks you for all the good references to my little gift to you, thats OK, no worries mate, if anyone wanted to avail themselves of one, see Gadget, he swares/raves by it ha ha, plus, you carn't have enough tools to do the job at hand.

jim


@Altrez
here are a couple of photos of my setups.
0793.jpg = My 5" toroid which I see you have almost replicated the winding positions to mine.
0794.jpg = This is the setup I used to drive a 12v DC fan motor, but I only could get to run a few seconds.
The toroid is a specially wound one, it has 12 "outs" or "taps", with this I can "select" any of the 12 energys avaliable to play with.
 
jim

Wow we have almost the exact same setup! I have been running all night and its still charging How did you set your cap up on your pickup coil?

What type of motor did you run? Did it have a load? It seems like the winding has a lot to do with how well the toroid will perform.

I will take some pics tonight. One thing I might also add is I am really stress testing the battery's lol. They have no time to rest between swaps. If I let them rest a few hours I am sure they would perform even better.

Take Care,

-Altrez

[electricme]

@Xee2,
Nice work with working out what is going on with the running of my JT, BTW, this was my very first JT, my first attempt ever, there is no secondary winding, just the Bifilar wires.

Just maybe the magnetic field within the toroid is influencing the turn "on" time lag, coupled with the cap. I wound every bit of wire I could fit on the toroid, ha ha, well in these early days we all were stabbing in the dark, and just to get the LED to light up was a real achievement.

This circuits History.
I decided to soup this one up by adding a switch on the power supply, added a adjustable resister in series with the 1.2v battery, put a switch at the LEDs so I could switch a Green LED or a Red LED and a switch to put a cap across the 1K ohm resistor.

jim