I am somewhat confused here. When we wish to create a biased transistor circuit, what are the parameters that WE decide and what are the ones that are already fixed or become dependant on our other choices.
For example, we have beta (current gain), Ic, Ib, Ie, Vc, Vbe, Vce among some others.
I have seen a circuit where Vce is chosen (and thus Vc for the given supply voltage), and Ic is chosen. But the problem is we can't just get that Ic since we need to get enough Ib as well, and use beta here. So at the end we Choose Rc, Rb. Fair enough,
Vbe and beta are fixed almost always for a transistor. Other things are chosen by us right? But how can we choose a Collector current value when in fact the value of beta is never constant as the one used by us in calcuations. Thus when we make the acutal circuit we will NOT get the same value of Ic (that we wanted and used to Rc to get) and Ib (which we found by using the required Ic) since even though Rc and Rb is same, the beta is different in the real circuit.
What I am confused about is whats the point of all the calculations when the real transistor is not going to have the beta value that we have used in calculation and therefore not going to produce the required Vce and Ic in practice? Why not take a transistor and use trial and error instead to get the required Ic and Vce??
For example, we have beta (current gain), Ic, Ib, Ie, Vc, Vbe, Vce among some others.
I have seen a circuit where Vce is chosen (and thus Vc for the given supply voltage), and Ic is chosen. But the problem is we can't just get that Ic since we need to get enough Ib as well, and use beta here. So at the end we Choose Rc, Rb. Fair enough,
Vbe and beta are fixed almost always for a transistor. Other things are chosen by us right? But how can we choose a Collector current value when in fact the value of beta is never constant as the one used by us in calcuations. Thus when we make the acutal circuit we will NOT get the same value of Ic (that we wanted and used to Rc to get) and Ib (which we found by using the required Ic) since even though Rc and Rb is same, the beta is different in the real circuit.
What I am confused about is whats the point of all the calculations when the real transistor is not going to have the beta value that we have used in calculation and therefore not going to produce the required Vce and Ic in practice? Why not take a transistor and use trial and error instead to get the required Ic and Vce??