I know a lot of supporters of FETs (Field Effect Transistor), especially MOSFETs. But BJTs (Bipolar Junction Transistor) have there use too.

I used BJTs all over the place already: as amplifier, as constant current source, as switching transistor and so on. The “run-off-the-mill” transistors are cheap an universally usable. But if you have to drive a little more power they are dissipating a lot of it, are becoming slower and slower or are really expensive in the bigger packages. But I already used from the common BC546 (who knew!) up to the bigger 25W transistors (e.g. BD249C) pretty much the whole spectrum. I like them because they are intuitive. Only if the base has it’s current, then the transistor is turning on. Pretty good for prototyping.

FETs, either J- or MOS_ or VMOS- or SIPMOS- or who-the-hell-knows-what-FETs, I usually only use them if I have to drive bigger currents and don’t want to use like a dozen of relais. I’m not using FETs a lot since BJTs are more familiar to me, but I have them on hand, too. Turns out in bigger power classes they are quite cheap. Also they don#t neet a base current, just a voltage on their gate which is easier for microcontrollers. But you always have to make sure the Gate has its right level at all times. Otherwise they act as antenna and then there’s a problem. But in contrast to the BJTs, FETs have way too many different categories (e.g. N-channel, P-channel, both channels are either enhancement type or depletion type, MISFET, MOSFET, SIPMOSFET, VMOSFET etc etc….). I’m just confused when to use which type….

Even though I always try to stay neutral, I personally like BJTs more, since they are analog and not digital only, but I’ll use MOSFETs too from time to time, if I need more power or have to switch it fast. But if you like FETs more, have fun with them! Both are essential to modern electronics.