my name is Nick and i'm new here! a friend of mine from here helps me so i can learn electronics! but many things he says i dont understand them so here i am! i want to bias a transistor so i can light a simple led! i know ohms law and how transistors work but i cant do it! please tell me stepbystep what to do!!!!!!!!!!!!!!!!!!!!!
Vebo is when the base-emitter of a transistor is reverse-biased. Then the transistor is turned off very quickly. When the base-emitter voltage of a transistor is zero then it turns off pretty quickly but not as fast as when the base-emitter has a reverse voltage. Most silicon transistors have a max allowed reverse emitter-base voltage of only 5V to 7V.
Vbe is when the base-emitter of a transistor is forward bised and the transistor is turned on. The forward voltage is about 0.6V for a low current to 1.5V for a very high current. Most little transistors have a Vbe of about 0.7V at a reasonable current.
Depends how you wanted it biased, and what you're trying to do with it? - there seems to be a random mention of an LED there?, so what's that all about?. Post a circuit diagram of what you're doing.
what about the above calculations why i'm getting wrong results?
also the 385Ω resistor gets hot!!!!!!!!!!!!!!!! my friend cant explain whats going on with the Ib and we get such results and about the hot resistor he says that is smaller than the power dissipation about 0,1W and needs bigger than 1/4W is that correct?
The transistor is biased with a base current of 2.3mA and has a collector current of about 30.1mA. The transistor is turned on hard so its collector voltage is about 0.1V.
The transistor is biased with a base current of 2.3mA and has a collector current of about 30.1mA. The transistor is turned on hard so its collector voltage is about 0.1V.
how do we measure this 0.1V? our transistor it is supposed to be switched on "hard" so the collector is not 0.1V right?
when you say that the emitter is 0V probably you mean that the we got common emitter right?
Look at the curve of the saturation voltage in the datasheet. With a collector current of 30mA and a base current of 3mA the typical saturation voltage (Vce) is only 0.075V. Your base current is a little less so the saturation voltage is about 0.1V.
our transistor it is supposed to be switched on "hard" so the collector is not 0.1V right?