And that is want is happening to your 2222 transistors.įurthermore, you are trying to use NPN transistors in a circuit designed for PNP transistors. The bicycle would simply be crushed under the load before it even starts. Using a 2N2222 in a circuit designed for a 2N2955 is like using a bicycle to haul a ton of freight. A 2222 is a TINY, SMALL-SIGNAL transistor capable of 1/2 Amp and 1/2 Watt. The frequency depends on many characteristics of the transistors and even the wiring, so you shouldn't use something like this for anything other than a lamp, really.Ī 2955 is a LARGE, HIGH-POWER transistor capable of 15 Amps and 115 Watts. Also remember that a circuit as simple as the one you posted will never be giving you a 50Hz sine. If you pick a different transistor, there's a chance you'll have to user other resistors, too.Įdit: if you just want to build a simple AC-generator, there are other circuits that use NPN transistors. You do need the resistors in order to limit the base current and stabilize the circuit. So they're behaving very differently.įor this simple circuit you could use about any standard PNP transistor that can handle the 12v (+ margin because of inductive load) and the 1A current (you're probably going to need a heatsink if you want to run this for more than a few seconds). NPN is the other way around, it conducts if the base electrode is at a potential higher than the emitter. In simple terms, the PNP transistor will conduct if it's base electrode is at a lower potential than the emitter. The 2N2222A is NPN and the MJ2955 is PNP.
0 kommentar(er)
