Ok. I tried my tutorial and I got all the answers wrong (except 1a). Worse still I can't attend the tutorial session.I have posted my WRONG answers to show that I have done my work. Can anyone pls correct my conceptual problems.
Q1a. max current = 50mW/2V = 25mA
b. I(0.5Led) = 25mA * 0.5 = 12.5mA // half of LED max current
R(c2) = (Vcc - V Led - V cesat) / 12.5mA
= ( 12 - 2 - 0.75 ) / 12.5 = 0.74Ω WRONG!
c. Ic = βIb
for minimum Ib, β must be 50.
25*10^-3 = 50Ib
Ib = 0.5mA (WRONG!)
d. Value of R b2 = (Vbb - V besat)/Ib = (5-0.75)/598μA = 7107Ω (WRONG!)
e. ??
Q6a. It is to amplify current Ib????? (right or wrong?)
b. It is to prevent leakage current. (right or wrong?)
BTW are there similar problems on any website? I am totally lost.
Thanks for the help.
Q1a. max current = 50mW/2V = 25mA
b. I(0.5Led) = 25mA * 0.5 = 12.5mA // half of LED max current
R(c2) = (Vcc - V Led - V cesat) / 12.5mA
= ( 12 - 2 - 0.75 ) / 12.5 = 0.74Ω WRONG!
c. Ic = βIb
for minimum Ib, β must be 50.
25*10^-3 = 50Ib
Ib = 0.5mA (WRONG!)
d. Value of R b2 = (Vbb - V besat)/Ib = (5-0.75)/598μA = 7107Ω (WRONG!)
e. ??
Q6a. It is to amplify current Ib????? (right or wrong?)
b. It is to prevent leakage current. (right or wrong?)
BTW are there similar problems on any website? I am totally lost.
Thanks for the help.
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