Question

I do not where to put this question: if vo= 10V at 30° C, in the circuit(please click/tap link) shown below, find it at 15° C and 65° C.

Answer 1

The current through the diode is a function of temperature:
$$
\large{
I=I_0\left (e^{qV\over kT}-1\right)
}
$$
see - http://www.pveducation.org/pvcdrom/pn-junction/diode-equation

Do you know the forward turn on voltage for diode 1N4148? If you do, then you should be able to calculate the voltage \(I_0\) and then find the current for any temperature T. Caution, T is in Kelvin.

Once you know \(I_0\) you can then determine \(V_0\)

Answer 2

please ignore the diode 1N4148...., and change vo= -8V at 30degC

my friend, and my prof did this:
\(\sf \large \frac{v_o'}{v_o}=\frac{I_R'}{I_R}\\65°\\I_R'=2^{\frac{65-30}{10}}I_R\\ \hspace{10pt}=11.3I_r\)

\(\sf \large \frac{ v _{o}-(-10) }{ { v '_{o}-(-10) }}=\frac{ 11.3 i _{R} }{ i _{R} }\\ \large \frac{v_o'+1c}{-8 + 10}=11.3\\v_o' + 10 =(11.3)(2)\\v_o' = 12.6V\)

Answer 3

I did not get how to do this...

Answer 4

So the diode is NOT in the circuit?

Answer 5

it is, but I it will be in reverse biased

Answer 6

@Hero

Answer 7

physics :)

Answer 8

lol... my math is physics right now, my electronic circuits course is like my math, adn physics.I do not know where to put it.

Answer 9

yep "find more subject" button is not working
http://openstudy.com/study#/groups/Physics here is aa link if you want to post it there or new question :)
thanks:)

Answer 10

Thanks