Joule Thief-- with tunable coil.ASF

This is a standard Joule Thief circuit with a tunable inductor coil. The simple one transistor circuit is powered off one 1.5 volt AA battery and is driving multiple LEDs in two locations. The coil is hollow and a ferrite slug is used to adjust it's three windings into resonance. A potentiometer at the transistor base is also used to fine tune the circuit. The 27 LEDs are on a Dr. Stiffler SEC tower and are-- IN SERIES! The one LED on the board is in the standard location off the collector. All of the LEDs can be made to light at the same time.

Category:

Science & Technology

Tags:

• Joule Thief
• Energy
• Electronics
• Led lighting

[powermaks]

wold this make a good florescent driver?

[Lidmotor]

@powermaks ------If you had enough winding on the secondary it probably would.  The nice thing is that the coil is tuneable and other FL drivers are not.

[powermaks]

what is the amp draw, and i see thousands of videos about the sec circuit. can you explain?

[Lidmotor]

@powermaks ------The amp draw is hard to measure on this because the "excited" energy field messes with the meters. I don't remember what this was drawing but the transistor was not hot so it must have been under a few hundred mA . Probably less than a hundred.

[EastcoastTinker]

Hi. Wond the coil and have the JT working. I could use a hand on the tower. Been having a problem finding the info on the EF. Could you give a run down of the construction and connection of the tower, or make a vid. More so on the constution. That would help so much.

[winn1971]

@Lidmotor thanks Lid for the prompt heads up. will pwm make a difference so extend the life of the 1.5V source? this is d nxt plan anyway as what u did in ur other iterations of d jt circuit. also, why is it the mor exprerimenters prefer toroid vs d rod? any specific reason? i find d rod easier to wind & is actually more available from wer i am. toroids r hard to come by, except d really small ones from pc psu. thanks again.

[Lidmotor]

@winn1971 ---I don't remember how many turns I put on that. This is really a study in transformer design. There is lots and lots of info on how these work and the "turns ratio" formulas to get the voltage that you want. Just Google "transformer designs". You will need to add many more turns to get the higher voltage. Remember that you trade amperage for the voltage though. It is going to take the jucie out of that AA pretty fast to light up a CFL. I found that out the hard way.

[winn1971]

@Lidmotor - exactly what's the no. of turns for the trigger/pri & sec. (how many hundreds) ur coils are? i tried this but with a fixed ferrite rod (antenna rod) with 500 turns for the secondary & the trigger/pri. coil on the side just like yours but could only lite a LED dimly of the secondary. when i transferred the trigger/primary on top of the secondary, i managed to get 120VAC off the secondary with a 1.5V AA input. i want to step the Vout to at least 375V to use for CFL. Any suggestions?

[Lidmotor]

@jaesungauzakim -----YES

[jaesungauzakim]

so... more turns in toroid the more LEDs you can light up with good brightness?