Need help with a discrete semiconductor diagram!

[prymal]

Solved. Thankyou.

 

[SJD]

Looks like some kind of homework? At least I struggle to see the point of the circuit, plus it is quite badly drawn, why is the top 9V rail not just drawn as one straight line?

So Branch 2, current = (9.0 - 0.7) / 1.0k = 8.3mA, and power in R9 = 8.3 x 8.3 mW = 69mW
Branch 5, current = (9.0 - 1.4) / 560 = 13.5mA, etc. (assuming also 0.7V for the LEDs).

I'm sure you can repeat the calculations for the other branches.

 

[prymal]

Yeah your right, it is homework. I completely agree with you, the diagram just confused me with the way that it was drawn.

Thank you for your help, very much appreciated!

 

[telectrix]

don't LEDs drop 2V across them?

 

[davethsparky]

Think it depends on the colour, ive got a feeling red/green/yellow are one point something and blue/white two point something

 

[prymal]

I think red/green/yellow are 1.7V

 

[Guitarist]

Seriously, ask your college lecturer.

 

[prymal]

Don't you think i would have done that by now if i could?

 

[Guitarist]

I don't know, as I don't know you personally. My advice is to get your text books out and work through it, as we all had to before the internet came along.

 

[LED Lighting]

Thats an easy one - for all intensive purposes treat the LEDs as having 0v Drop as you dont have any information regarding them!
Like said above that drawing is beyond!

I will do the first 1 for you and you can do the rest!

R1 + R2 + R3 = Voltage drop of 9v
R1+R2+R3 = 13k ohms - 0.69k volts per kohm (rounded off!)
R1 = 6.92v drop (rounded off!)
R2 = 0.69v drop (rounded off!)
R3 = 1.38v drop (rounded off!)
v1 + v2 + v3 = 9v


Current Drop - ohms law!
V=IR
I = V/R
R1 = 9/10k
= 0.9mA

You can do the rest!

 

[VoltzElectrical]

my opinion is that there should NEVER be genuine questions like this from students (in an ideal world). However, being that I Told my useless lecturer to eff off once he did a half decent lecture whilst being observed, then returned to being a useless ****ttt, I can understand the enquiry.

Unfortunately, people like Alan Thomas at Neath College are letting people down by hiding behind sham assessments of their ability and relying on learner's own desire to accumulate knowledge for themselves.

Note to Alan - although I was forced to apologize to you, I didn't mean it. You are a complete joke of a lecturer, and everything I learned, i learned off my own back from reading the book.

 

[LED Lighting]

I had the same with my lecture who thought me my 17th Edition - he didn't even know the material himself so how on earth could he teach us it? - he was using the BRB not BGB!

He then thought us 2391 and again teaching us from the wrong book!

The number of times students corrected him was beyond a joke - he was made to take an early retirement @ 45 after several of us complained!


I also had an 3rd year student with me last summer - the useless t*** could not even wire up a flipping socket not long hang some trunking straight!

 

[SJD]

don't LEDs drop 2V across them?

Wikipedia seems to have quite a nice table of LED colours vs. voltage drop, I was surprised to see some are well over 2V, even over 3V (when I was at college, LEDs were red, or possibly yellow or green).

See Light-emitting diode - Wikipedia, the free encyclopedia

However, the original circuit has now morphed into some piece of "artwork".

 

[HandySparks]

However, the original circuit has now morphed into some piece of "artwork".

It has. I suggest that the OP puts the original diagram back so that this thread makes sense or never shows his face here again.