1. The problem statement, all variables and given/known data My question concerns MC7805, integral regulator, used as a high current voltage regulator. See figure attached. Now, I am told that Ry=7.5Ω and that Q2 is on the verge of conductance with VBE,on=0.5V. Using the Max. Quiescent Current from the manufacturer's data sheet (see attachment) I am asked for the maximal load resistance which could be attached so that Q2 would still not conduct. 2. Relevant equations 3. The attempt at a solution Based on the data sheet (unless I misread the info. there), the Max. Quiescent Current is 8.0mA. Should the calculation hence be 5V/8mA=625Ω? Am I given the value of Ry so that I may deduce that most of the current would be passing through it (as its value is quite small)? On the verge of conductance the current flowing through it would be 0.5V/7.5Ω but how does/should that affect my calculation?