can any NPN transistor be used to make joule thief.....and 1kohm resistor is only necessry to make it???????????

iam making joule thief....................can i use any Npn transistor to make it and only 1kohm resistor be use??? it work on different value of resistor.............?????????

trubshac7 years ago
Yes almost any sort of NPN transistor should work. The value of the resistor is not critical either so long as it is relatively small (470R to 2k). The number of turns on the coil and the exact type of core that you wind it on is also not that critical (you can use a steel bolt!). The best thing to do is try it with whatever you have to hand - if it doesn't work, keep changing things (different resistor, different number of windings etc) until it does work - maybe you can come up with an ever better design just by experimentation!
mhkabir8 years ago
A NPN transistor with faster switching speed could get more juice out of the 'dead ' batteries.
mhkabir8 years ago
It will work,but in terms of efficiency it will waver.In an higher value of NPN transistor, It will will be more efficient,but you will need to change the winding of the toroid and make the winding thicker and the resistor shoul be 2k.No reason that any NPN transistor in the 2N3000 series will not work.