My joule thief is not very bright?

My joule thief is not very bright? I've changed the windings, transistor and the resistor; and it is still pretty dim. Help please Parts: 2 different size toroids: Large and Small 3 Transistors: 2n2222, 2n3904, 2n5830 2 Resistors: 1k, 2.2ohm blue led white led with a heatsink Also I used a 20awg and 36awg to make the toroids

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I suspect you simply haven't got the energy available from the battery driving the Joule thief, nor have you got the current handling you need - close to 300mA. A Joule thief is a very neat thing, but it "cannae brek' the law's o' physics" to coin a phrase.....
daemonral (author)  steveastrouk8 years ago
Thank you, I think I understand.
Try feeding it with a good low voltage supply. A 'C' or 'D' cell should do it. Try using a thicker wire on your windings. The transistor can handle up to 800mA, but the gain will fall off as your collector current increases. Try and Change LED. Use a red one. Make some measurements with an oscilloscope. Steve
You SAID its very bright, how can very bright be very dim ?
daemonral (author)  steveastrouk8 years ago
I'm sorry I meant to type dim I must have blanked out
What's the LEDs rating ? Steve
daemonral (author)  steveastrouk8 years ago
1 W 3.7V 40 lumens
Joe Martin8 years ago
Have you tried a different battery?
daemonral (author)  Joe Martin8 years ago
yes, I have changed to a new battery.
lemonie8 years ago
Pictures, parts, specifications and a circuit diagram would really help here (otherwise people are just guessing). L