Joule Thief

[Pirate88179]

Well I am now up to page 200 in updating the other diagrams topic.  Whew!  Not even halfway done.

Bill

[jeanna]

Good job Cap'n,

Your work makes the job of researching the older posts much easier.

Thank you for all of it.

jeanna

[hazens1]

Added another pickup coil to the 7-7-70 that was getting ~250 volts. Now the first Pickup gets 230 volts and the new one gets 160 volts. When I run them through 2 seperate bridges then tie the bridges in series, I get 330 volts unloaded with a 1.2 volt 100ma input from a 1k ohm resistor. When I drop the resistor down to 500 ohm the dual bridge goes to 350 volts and the input goes to 120ma. Much better than the 250 volts at 125ma from the single Pickup coil. The second pickup coil doesn't get as many volts on it's own since part of the wind is not right next to the toroid. Pictures to come in the near future. Also since the 2 pickup coils are not equal in position relative to the toroid the circuit sings 2 seperate notes when it resonates. Dual tone for the win, maybe..  I'm going to wind a new one but wind the multiple pickups at the same time to even them out similar to the MK series. Will probably still end up with about 350 volts total for 2 pickups. Maybe I will drop the wire size to 30ga and squeeze in 4 pickup coils. I also plan on adding a third or forth pickup to this coil so I can see if it will resonate with 3 or more frequencies. Maybe I can make a whole orchestra from a single toroid 

[Pirate88179]

hazens1:

Excellent job man!  Did you say this was from a single AA battery on your JT coils?  350 volts, now that is well within the Fuji territory some of us had been working in earlier.  To my knowledge, no one has achieved this much output on hand wound toroids here thus far so.....very, very great job!  I know one of Jeanna's goals was to reproduce our Fuji results using the regular JT type circuit and it appears you have now done so.

I know you said photos were forthcoming but can you please post a step by step, or schematic of your circuit as I know, myself included, other will want to replicate it.  I am very excited by this so again, great job and thanks for posting.

Bill

[jadaro2600]

There seem to be a number of variations on the joule thief design...  insofar as I can tell, there is flyback on the coil-to-base.

Has anyone thought about the flyback pulse charging the battery?  ..this would require the resistor to be behind the coil and at the base of the transistor.

An initial idea.  Diagram Included.  Does anyone have the charging characteristics of a single AA rechargeable battery on hand?