But if you set Vout = 5.5V and then allow the voltage to drop from 5.5V to 4.5V then the error will be bigger then ±10 ?
(5.5-4.5/5.5) x 100 = 18%
But it seems that I'm wrong

The original problem stated that the output voltage should be 5V ±10%, which is 5V ±0.5V.

 

Guys, thank you so much for your help. After all your posts and comments i understand how a problem such as this one can be approached. I had never done such a problem before and never seen any examples by my prof reguarding a variable load so had no idea how to approach it. I was stupid for not considering the +/- 0.5 volt tolerance in my initial attempt, but hey somewhere on that first post i did have r1=2r2, so im proud of that. Although i shouldnt post this because it could probably get me in trouble im going to do it anyway, below is how it was done with your guidance of course.

 

Also i could probably do this again, with the Vout being 5.5 volts under no load and 4.5 volts under load to see what happens. I may also try by using Kirchoff's laws.

 

Also i could probably do this again, with the Vout being 5.5 volts under no load and 4.5 volts under load to see what happens. I may also try by using Kirchoff's laws.

As I said, I think you'll get a better grade if you do.
What sort of academic program are you enrolled in?

 

As I said, I think you'll get a better grade if you do.
What sort of academic program are you enrolled in?

Hi Ron,

Im a first year electrical engineering student. I will work on the other possible solution later tonight and post back

 

Hi, i performed the calculation with 5.5 Volts being the unloaded voltage and get:

R1= 545.44 ohms
R2= 315.78 ohms

Since i will be connecting these circuits in a a lab what do you guys think i should use?
Resistors as 150 ohms and 300 ohms are easier to come by then connecting several in series.

 

From the standard values (E24) you should try 510/300 or 470/270.

 

From the standard values (E24) you should try 510/300 or 470/270.

I think I would go with 470/270. 510/300 will put the unloaded voltage at 5.56V, which is slightly out of spec.

 

you guys are great ran them in the simulator ill try both the 150 and 300 as well as the 470/270 for my lab.

Thank you for all the assistance you have provided!

matt.