Joule Thief

[dllabarre]

Currently my JT is down to 277.6mV and the 3 red LEDs are very dim but still visible.  When they do go out the battery will enter its "bounce back" cycle.  Then if it bouces back enough the LEDs will light and start dropping the battery down again.

Here is the range for my JT.
When the battery gets to 276.7mV the LEDs are not visible.
If I disconnect the battery for 5 seconds, upon reconnecting the battery, it goes into its "bounce back" cycle. 
When (IF) the battery gets up to 346.7mV then the LEDs will light up and the battery starts to go down again.

I have let the battery go down to 272.6mV before disconnecting the battery to initiate the bounce back.
I wanted to determine if it would automatically go into the "bounce back" cycle but it didn't even at 272.6mV.

DonL

[xee2]

@ dllabarre

Here is the range for my JT.
When the battery gets to 276.7mV the LEDs are not visible.
If I disconnect the battery for 5 seconds, upon reconnecting the battery, it goes into its "bounce back" cycle. 
When (IF) the battery gets up to 346.7mV then the LEDs will light up and the battery starts to go down again.

I have let the battery go down to 272.6mV before disconnecting the battery to initiate the bounce back.
I wanted to determine if it would automatically go into the "bounce back" cycle but it didn't even at 272.6mV.

DonL

Thanks for the info. I do not know if anyone else finds this interesting, but I do. I always thought transistors would not work at such a low base voltage.

[stprue]

Deleted

[stprue]

Ok it's still being processed but it's up and running.


http://www.youtube.com/watch?v=IsslTUxX-VE

[jeanna]

Well stprue,

That is pretty interesting.
Some of the hook up details were unfortunately off screen, as I am sure you are aware.
I will try to make a drawing for myself out of what information is there.

It must all be in the way you made the connections, because you are only using -was it- 4 turns per secondary.

One end of each secondary (was it going around the toroid the same way?) goes to each side of the bridge.

Your pot is not connecting to the base but instead to the emitter?
It was kind of off the screen there so remains a mystery.

The next thing you show is another wire from the second pickup that "goes to the base, of course".
NOT

You would seem to be skipping the resistor to the base?
The pot connections would be helpful to see since that is the oddest part of this arrangement.

How many turns were on your  MK1 primary?

Did you ever try this withOUT the bridge?

thank you,

jeanna