Help On Another Transistor Question

[sundin13]

Well it didn't take me long to get stumped again.  The only formulas I have for ICQ & VCEQ need a VBB.  With this circuit there is no VBB, am I right?  Any help would be great.  We're not using any curve charts or data sheets, just formulas, which are not in my text book.  Q is queiscent. ???


Determine:

a.)  ICQ (in mA)  (Without using Vb= VccxR2/(R1+R2)) <---voltage divider

b.)  VCEQ (in Volts)

Regards....

View attachment 38506

 

[audioguru2]

1) R1 and R2 make a voltage divider. You don't need the formula to determine their divided vol tage, just use Ohm's Law.
2) Subtract the Vbe voltage to determine the emitter voltage and its current.
3) Use Ohm's Law to determine the collector voltage from the emitter current.
4) If you want to get extremely accurate, correct the calculations using the value of beta that is given.

 

[sundin13]

I've got it figure out.  The Q was throwing me off. 
As far as I know the Q-point is on the dc load line if I'm not mistaken. 
This stuff doesn't get any easier thats for sure. 

 

[audioguru2]

By 'quiescent', do you mean DC?
Is it always Synonymous to DC?

Its quiescent-point is when it rests without signal. Its DC conditions.

 

[ante1]

I call it idling!  ;D

 

[bhargava]

Hi Sundin,
I've worked the problem out for verification these are the answers
IcQ =1.64mA
VCEQ= 6.68V
The equtions used the logic ,theory  almost every thing is lucidly explained in 
Electronic Devices and circuits by MILLMAN & HALKIAS from TMH

ok then Bye...
Bhargava