Hi there,
I am having trouble getting my voltage drop values across each resistor to add up to the source voltage. I can't for the life of me see where I have gone wrong and its driving me nuts as I'm sure people on here will probably understand.. its driving me insane

If anyone can see the error in my ways I wold be so grateful !?!?

I have attached a 3 pics;
the original circuit diagram (its a trick question - and its working)
my table of values - where something has gone wrong, I've stopped before completing it because it wasn't adding up.
my redraw's in case that's the problem

I hope someone is out there who is up for it, please help?

Thanks

ps pls excuse my hand drawing, I am yet to figure out how to get eagle to put components in on an angle. One thing at a time I guess

 

What were you asked to find?

Once you get those 61,5 ohms, what are you suposed to do? Calculate current? You did, so...

 

I do not see any error:
Vsup = VR1 + VR3 or VR2 + VR4
Vsup = 10.5V + 13.5V = 24V ??
Vsup = 4.8V + VR4 = ??

 

maybe that 390 ma indication confuses you

 

Hi ! Yay.. it sounds like this is not going to be an mystery forever THANK YOU hopefully

To my understand thing , the 390mA is the Total current.

IT - VT/RT

IT = 24v / 61.5 ohms = 0.390A


I dont understand what I am missing.. Is there another step beforehand or ??? please?

 

Hi ! Yay.. it sounds like this is not going to be an mystery forever THANK YOU hopefully

To my understand thing , the 390mA is the Total current.

IT - VT/RT

IT = 24v / 61.5 ohms = 0.390A


I dont understand what I am missing.. Is there another step beforehand or ??? please?

I dont understand what you are missing either since you know what the current/voltage is in every element of your circuit

 

Oh.. Jony130, you're right. Whats happened is that I have gone and added up ALL the voltages as if ALL resistors were in series;

R1 + R2 + R3... and obviously ended up exceeding 24volts ,

The answer thanks to you guys for helping me see, is;

VT = Voltage Drop across R1 + R3 = 10.5v + 13.5v = 24v
VT = Voltage Drop across R2 + R4 = 4.8v + 19.2V = 24v

Thank you, well I've managed to be wrong even when I'm right ha, thats gotta be some kind of record heh. Thanks again