- #1
tamtam402
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I succesfully did this example from my book without checking the solution, but I came up with a question that I cannot answer on my own. What would happen if Re was set lower?
The base is grounded and Vbe is independant of the current Ie, so by choosing a resistance smaller than 7070ohm for Re, it seems like the equation Ie = Ib + Ic wouldn't hold anymore, which is impossible. So, what would happen if I were to set a Re too small?
Basically, I have a problem where the book says the emitter current should be 2.02mA. Yes, that's what I calculated, but what would happen if I were to set a value for Re that makes would give a 3mA current, for example?Since the scan didn't work properly (the book is huge and I couldn't make the whole page fit flat), here's the first paragraph:
The transistor in the circuit of Fig. 6.14(a) has B=100 and exhibits a Vbe of 0.7V at Ic=1mA. Design the circuit so that a current of 2Ma flows through the collector and a voltage of +5V appears at the collector.Edit: I didn't scan the second page. It's simply the last equation of the first page with the values replaced for Ve (-0.717V) and Ie (2.02mA).
The base is grounded and Vbe is independant of the current Ie, so by choosing a resistance smaller than 7070ohm for Re, it seems like the equation Ie = Ib + Ic wouldn't hold anymore, which is impossible. So, what would happen if I were to set a Re too small?
Basically, I have a problem where the book says the emitter current should be 2.02mA. Yes, that's what I calculated, but what would happen if I were to set a value for Re that makes would give a 3mA current, for example?Since the scan didn't work properly (the book is huge and I couldn't make the whole page fit flat), here's the first paragraph:
The transistor in the circuit of Fig. 6.14(a) has B=100 and exhibits a Vbe of 0.7V at Ic=1mA. Design the circuit so that a current of 2Ma flows through the collector and a voltage of +5V appears at the collector.Edit: I didn't scan the second page. It's simply the last equation of the first page with the values replaced for Ve (-0.717V) and Ie (2.02mA).