1. The problem statement, all variables and given/known data Determine V_{C} for the network in Fig. 7.24 (left-hand image). 2. Relevant equations Kirchhoff's Voltage Law: The algebraic sum of the potential rises and drops around a closed path (or closed loop) is zero. 3. The attempt at a solution This is an example problem in my book "Introductory Circuit Analysis" by Boylestad, 12th Ed., page 256. I understood KVL in the chapter on series dc circuits. There, closed loops were obvious. My hangup with this question is I don't see how Fig. 7.25 represents a closed loop. The book states: [tex]V_{C}+V_{R_C}-V_{CC}=0[/tex] Why are we subtracting V_{CC}? Can somebody post a Microsoft Paint drawing to show me how Fig. 7.25 is a closed loop?
People like you are what make this site among the best on the 'net. You responded within minutes of my OP. Thank you. So is there a rule of thumb that I can use when I run into this dilemma? What about the circuit told you that the battery was definitely hooked up as in your image? I mean, it would be feasible to draw the battery into the circuit a different way (as in below) and get a different result, right?
Your circuit is different from the original one. The emf of your battery is 2 V, Vcc =22 V can not be supplied with such an arrangement, without an additional battery. The potential must be 22 V at the point shown with respect to the ground, which is at zero potential. That is the maximum potential shown: there must be a battery with that emf. The real transistor circuits have some supply voltage, a battery. That is what I drew. The Base voltage is obtained by the voltage divider R1 and R2 in series. I know it because I have made a lot of such circuits... ehild
OK, now I see it... The branch you added to the left was there to begin with and it is the long-hand way of drawing in V_{CC}. Correct?
I do not know what long-hand way is, but the battery was there. Maybe, not really a battery, but some other appliance for power supply: transformer connected to 230 V ac, with rectifier and stabiliser and so on, with output 22 V dc. ehild