International Alternative Energy Center
International Alternative Energy Center
Home | Profile | Active Topics | Active Polls | Members | Private Messages | Search | FAQ
Save Password
Forgot your Password?

 All Forums
 Circuits and Diagrams
 40 Watt Joule Thief
 New Topic  Reply to Topic
 Printer Friendly
Author Previous Topic Topic Next Topic  

Average Member

418 Posts

Posted - December 25 2011 :  10:05:10  Show Profile Send Poppy a Private Message  Reply with Quote
Hi Everybody...

Here is a circuit I've tried a couple and never got it tuned properly, maybe someone can build it and make it work.

~~~Life's greatest FAILURE is not learning for our MISTAKES!~~~

Good Experimenting...

Google AdSense

Mountain View


1107 Posts

Posted - December 28 2011 :  07:41:59  Show Profile Send kcarring a Private Message  Reply with Quote
I have a video of me building this one.

You must be logged in to see this link.

I would have ran with it in the greenhouse but I got plasma in the bulbs, they blackened fast. Maybe I messed something out.. not sure, it's been a long while. Good learning experience though, teaches you all about feedback windings. There is a version with a tuning transistor. The low volt version (for me) worked out (OK). Quite possibly it would have run the curly-Q type CFL's fine. I may also have had too high of voltage, the guy who drew up the circuit was running 240V - who knows maybe 240V bulbs are actually meant to step up higher than 110V's. Its 110VAC here in Canada. Looking back at it now, that 13 turns feedback, that almost seems a little excessive.

Do you still have the transformer built?

if you didn't get it to oscillate try swapping the feedback windings around. Run the circuit with a rheostat at first, too. Try polyester or tantulum caps of high voltage as well instead of those *Nice*ty little ceramics like I used.

* There is a better circuit on Instructables that is from a guy who obviously built this, then improved it with a toroid, and added a tap on his run wind for element heating. Also see jeannas light. Or Lidmotors Jeannas Light. This is more of true inverter than a Joule Thief in that it gets a hard driven feedback going on.

Edited by - kcarring on December 28 2011 07:54:14
Go to Top of Page


4489 Posts

Posted - December 28 2011 :  09:36:06  Show Profile Send 49er a Private Message  Reply with Quote
Hi Poppy

I can't see the link help please

The sky is not the limit...There are footprints on the MOON.
Your only as DUMB as where your standing.
No matter where you go there you are.
You must be logged in to see this link.
Go to Top of Page


1107 Posts

Posted - December 28 2011 :  14:14:42  Show Profile Send kcarring a Private Message  Reply with Quote
Looks like the same one as in my video, which came from here:

You must be logged in to see this link. (click on 12V inverters on the left frame).

Here is an interesting variant:

You must be logged in to see this link.

This currently the circuit i want to build next, and seems like it has had the most work put into it (and seems to be) the only one that addresses the fact the longer tubes really need an element "heat up".. the spiral ones seems less dependant on this.

Here is the instructable, make sure you read the comments...
You must be logged in to see this link.

The author actually made improvements on the circuit and later posted a new circuit in the comments, and that one, I'll show here:

I might try this with mosfets.

If you plan on firing spiral bulbs with their guts removed, honestly I figure this is the by far simplest way to drive them hard:

XEE2's circuit.
You must be logged in to see this link.

It worked great for me, but after a few minutes I saw the dreaded plasma appearing, (using straight tubes) as I have always seen, in every circuit I have built, with the only exception being the Slayer, which needs to be driven with MOSFETs to truly get the current and brilliance up (for me, that was the 10 watt level). So I'm still at odds, which leads me to the first second, for my next attempt, as I have about 100 bulbs already, I need to light up... and on a side note, the standard new style circuits employ a SMPS circuit (instead of the old ballast) which, in my experience, require sine wave inversion, which can cost you almost double the watt requirement expected. This stuff has actually been a long haul for me. I do however, have some faith in the jonnydavro variants of Slayer/SEC, as not only do they have low input requirements, but the coils aren't large or expensive to build. Offgrid CFL isn't as simple as I thought it'd be, over a year ago, many experiments later... that is... if you want to use straight tubes! Also, a side note: In the past I have failed to use HV polyester caps, which also could be part of my lack of success.

(* see XEE2vids joule thief variant for HV with jonnydavro inductor above, for the circuit of this demo)
Here is my go at that circuit:
You must be logged in to see this link.

If you look carefully at 0:47 you can see that purple starting to form in the ends. That's what I am talking about... after a few hours that purple turns to black, as the plasma eats the coating off the bulb.

if CFL isn't a concern...

As far as straight out "best value" (lumens vs. watts in), I think the XEE2 JT driven off of 3.7V Lio-Ion gave me the best results I've seen, shown here: You must be logged in to see this link.

As far as usability, overall, when a room need be illuminated a bit more than what you see above, I think my PWM mod to the flip flop driven at 3-4 watts was the best, shown here: You must be logged in to see this link.

* side points:
The Magneticitist's newer demo of charging and creating lighting looks very promising.

The Slayer can do a LOT better than I've shown it too, but it takes some time, finding resonance (I haven't, truly, yet). A bit of luck perhaps doesn't hurt either. Mine hasn't been "the best". I really like where jonny is going with lending more toward the Stiffler circuit, smaller coils, because when it comes to CFL drivers, there is little point in spending $30 to drive a bulb. Especially if you want to drive 100 of them in a greenhouse, off grid.

Edited by - kcarring on December 28 2011 15:19:59
Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
International Alternative Energy Center © 2000-2009 Go To Top Of Page
This page was generated in 0.33 seconds. Snitz Forums 2000
RSS Feed 1 RSS Feed 2
Powered by ForumCo 2000-2008
TOS - AUP - URA - Privacy Policy
ForumCo Free Blogs and Galleries
Signup for a free forum or Go Banner Free