Joule Thief Circuit - Driving CFLs with 1.5v

In the "Big Joule Theif" thread of the Energetic Forum some wizards are producing light from CFLs using only 1.5 volts. There are hand-wound coils, and clever circuits being experimented with. This is all great fun and may lead to a very inexpensive, low power lighting system.
Here is my attempt, which utilized many ideas I've seen from others from the Forum. What a thrill to participate in this "shocking" research. I am so amazed that you can light CFLs using a 1.5V battery. It seems impossible ... but resonance is a science we have yet to tap effectively.
My contributions to this effort are to try to use off-the-shelf parts -- so that people don't have to wind their own coils -- and to keep part count and complexity low.
Those electronically inclined might take a stab at replication. Search for Jeanna's Light too and check that out. We want to start a nice friendly competition to see who can light the lights the brightest with the least power. Hint ... go BIG on inductance!!!

Category:

Science & Technology

Tags:

• Resonance
• Joule
• Thief
• Inductor
• Low
• Power

[nicetarig]

thanks. can we use earth battery????

[morpher44]

@nicetarig

Sure. Some folks are doing that. See energetic forum.

[xxDarkGregxx]

@nicetarig I'm planning on using recycled solar panels from broken garden lights to charge the battery

[morpher44]

@xxDarkGregxx

Battery choice is tricky. NiCads don't do well with heat. Led acid works great, but is environmentally not very friendly and can dry up. NiMh .. expensive. Some folks are using super capacitors instead...

[xxDarkGregxx]

@morpher44 What specs would you suggest for super capacitors?

[morpher44]

@xxDarkGregxx

Largest capacitance you can get within your budget. Be careful with these. Be sure to discharge them before grabbing them.

[Davetech23]

Opps, sorry. I now see that you have already answered that you don't recall the current measurement.

[Davetech23]

Very nice work! I thought the music was cool also.

I too am interested in lighting from an earth battery system. How much current were you drawing in order to light the cfl to a point which would be "usable" room light? I fear that it might take a very sizable earth battery system to reach my goal, but I hope to be otherwise surprised.

[morpher44]

@RightQuiteNot

Typical D cell is 12000mAh. Depending upon the current you drain, the hours you get varies on a curve .. with lower current being more ideal. Let say you are 25mA. That is approx. 480 hours or 20 days. Some folks have made these joule thief run real low current 5mA .. To be honest, I don't recall what current I was pulling that day .. but it was pretty low. The trick here is to make it as low as possible... and a bigger coil helps... but you also have to TUNE for CFL resonance.

[RightQuiteNot]

Two questions: How long do the lights go on the D cell? What is the voltage of the battery once the lights go out?