Joule Thief

[Pirate88179]

Happy New Year Jeanna!!!  And Happy new year to all on this topic!  2009 WILL be a good year for all of us.

Bill

[electricme]

@Timmy1729
I went and had a look at the Fairchild web address you posted, the KA7905 in the TO220 is a fixed output voltage regulator, which is used in the negative rail of circuits. Its equilivent in Positave circuits would be KA7805

KA or LM denotes the manufacturer
The 79 denotes a negative device
The 78 denotes a positave device
The 05 denotes the set voltage OUT, it will only alow 5volts out, you could put 12v DC into it, but only 5volts comes out. (use a heatsink).

If you want to have a adjustable output with a knob to adj the voltage range from 2 - 28 volts, use a LM317 in a TO220 package.
I don't recommend you use this on your LED JT

Most PC power supplies use MOSFETS in their switchmode circuits, these are designed to switch voltages on and off rapidly and would not work with the JT.

@all
Darlington transistors
There are several avaliable BC517 or BD139 for starters.
Try the BC517 first, if it carnt handle the current, use a BD139 instead.
Read up on them here http://www.electronics-radio.com/articles/analogue_circuits/transistor/darlington-pair.php or here http://www.best-microcontroller-projects.com/schematic-symbols.html
or read the attatchments.

@bill
I love your photos of the extra LEDs on your last xmas tree posts, nice and steady, very clear and bright.
Wear a pair of surgical gloves, might stop some of the shocks 
Well done and happy new year.

jim 

[Pirate88179]

@ Jim:

Thank you!  Happy New Year to you also.  Yes, the gloves might be a good idea for me since I do not seem to learn very quickly.  Take care.

Bill

[markdansie]

Thanks Xee2 and Bill for the info.
I am looking at using it for camping as well.
Thanks everyone for the ideas and effort...it has been a great holiday read.
Kind Regards
Mark Dansie
Aussie

[WilbyInebriated]

happy new years all!

i found a way to run these circuits (well the kk05a6 anyways) on 3V without changing resistors or anything. 3V @ 250mA. it runs cooler than with 1.5V and the bulb has good (relatively speaking) brightness. it has been running for a half an hour now.
i just got set up to take some pictures and turned my camera on to find out my batteries were low and it shut off, grrr.
back with some pictures when the bedini sg finishes charging batteries.