I have tried this problem a number of times and I keep getting -177.78. This seems a bit crazy. Any advice?

 

I tried I(load) = I(I) = ( V(PS) - V(Z) )/Ri
using V(PS) = 14V and V(Z) = 9V
So I got 312.5 mA for no load I(L).

Not sure where I should go from here.

 

I tried I(load) = I(I) = ( V(PS) - V(Z) )/Ri
using V(PS) = 14V and V(Z) = 9V
So I got 312.5 mA for no load I(L).

Not sure where I should go from here.

Try starting with the first question, then do the second question.

 

The diode is reverse-biased, so Vz should remain approximately constant at 9V, right?

Do I just work with the average Vps = (14+12)/2 = 13?

So the Voltage drop across the resistor should be
Vs = Vps - Vz
= 13 - 9
= 4 V

And Ii = 4/16 = 250 mA

At no load, I(Z) = I(i) = 250mA because of the open circuit

Then at full load, I(Z) = Ii - IL = 250 - 100 = 150 mA

Then load regulation = (250-150)/250 = 40%

Does this make sense?

 

I edited a step up top now. Still feel weary about my answer though.

 

Do I just work with the average Vps = (14+12)/2 = 13?

Is that what you were taught to do?

I'd do the calculations once for each combination to determine the worst case conditions. Or you can think about it and only do the calculations that would give worst case results; which is what you want if you're going to calculate load regulation.

 

Is that what you were taught to do?

I'd do the calculations once for each combination to determine the worst case conditions. Or you can think about it and only do the calculations that would give worst case results; which is what you want if you're going to calculate load regulation.

Thanks! I think you're right.

 

The first thing you need to do before you can calculate load regulation is be sure that you understand what the definition of load regulation is. What does it tell you? What information do you need to calculate it? Given that information, what is the actual calculation that needs to be done?