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Joule thief's....? Answered

Do all the components make a difference in the efficiency of the joule thief? i.e type of transistor, resistor, capacitor...



Best Answer 10 years ago

Yes they do in theory, although by how much I have not measured. The transistor is used as a switch in the circuit, either ON or OFF. A transistor that switches faster will waste less energy, as will one that gets to saturation at a lower current. (saturation : when the Base current is high enough that the Collector-Emitter resistance is lowest, ie transistor fully ON) A 'better' transistor leads to the Base drive needing a smaller current for the transistor to reach saturation. You can use a higher resistor value, which means less energy wasted.