# Need Help in Electronics devices

Discussion in 'Homework Help' started by full, May 3, 2014.

1. ### full Thread Starter Member

May 3, 2014
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Jul 18, 2013
10,271
2,269
...............and the question is???
Max.

full likes this.

May 3, 2014
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4. ### shteii01 AAC Fanatic!

Feb 19, 2010
3,297
482
Seems simple enough. I think textbook should have example or two on how to solve this type of problem.

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5. ### full Thread Starter Member

May 3, 2014
225
2
http://postimg.org/image/74ghsdpul/

if simple for u !
can u explain how get answer i1 and i2?

thanks

6. ### SneakSZ New Member

Sep 19, 2012
10
1
Use Thévenin to create an equivalent schematic at the base of the transistor.

Rb= R1//R2
Vb= (Vcc*R2)/(R1+R2)
Now you can find Ib ==> Vb = -Ib*Rb -0.7 -Ie*Re with Ie=Ib(beta+1)
Ib= -(Vb+0.7)/(Re(beta+1)+Rb)

Go back the orignal schematic and now you know what current is flowing out of the base.

Vcc = (I2+Ib)*R1+I2*R2 ==> Find I2
I1 = I2+Ib

Mind the signs.

May 3, 2014
225
2
thanks bro