ok, i will see more deeply!!

 

Here i design voltage divider bias transistor, pls check!!

 

Your transistor is missing an input coupling capacitor so the generator is shorting the base of the transistor to 0V most of the time so its output is high most of the time.

Also, the input signal has a peak of 1V which is much too high since the transistor has a voltage gain of about 180 if it has an input coupling capacitor. With a supply of only 10v then the output cannot be 180V.

The resistor values of the biasing potential divider are much too low so I have wasted my time explaining transistor biasing to you.

 

no sir, i have checked the current in voltage divider bias and base current it was higher than base current.

 

no sir, i have checked the current in voltage divider bias and base current it was higher than base current.

But you have the base voltage of the transistor DC-shorted to ground through the generator because your circuit is missing an input coupling capacitor. Then the transistor is cutoff most of the time.
But your transistor is biased wrong anyway so it will be saturated most of the time if you add an input coupling capacitor.

You need to learn about, not simply copy electronic circuits.

 

But this is obviously so simple. Just some electronic LEGO's that you 'snap' together, and viola, instant working circuit! What means 'resistive' solder joint? The bigger the blob the better the job, ey what!

pls reply

 

What means 'resistive' solder joint? The bigger the blob the better the job, ey what!

It takes years of experience to learn from what height to drip the solder onto a solder joint.

 

But you have the base voltage of the transistor DC-shorted to ground through the generator because your circuit is missing an input coupling capacitor. Then the transistor is cutoff most of the time.
But your transistor is biased wrong anyway so it will be saturated most of the time if you add an input coupling capacitor.
[/QUOTE
My teacher said the coupling capacitors used is for blocking dc and passing ac, how to find transistor biased is in saturated mode not in active region ??

 

But you have the base voltage of the transistor DC-shorted to ground through the generator because your circuit is missing an input coupling capacitor. Then the transistor is cutoff most of the time.
But your transistor is biased wrong anyway so it will be saturated most of the time if you add an input coupling capacitor.

My teacher said the coupling capacitors used is for blocking dc and passing ac, how to find transistor biased is in saturated mode not in active region ??

 

You need to learn about DC and AC.
You need to learn about how to bias a transistor.
You need to learn about how a transistor is cutoff and how it is saturated.

 

pls. tell can we use Boot strapping, other then in darling ton amplifier??
& give some more use of it then high input impedance.

 

Wikipedia is your friend, the resources are out there.

The word is Darlington, or Darlington Pair

While you are about it, look up Sziklai Pair.

 

Hello,

Here is a page with a lot of links and videos on transistors:
http://www.101science.com/transistor.htm

Bertus

 

the link is showing this images!!
what does it mean??

You need to scroll down to see the schematic and parts list.

 

here is the ckt. pls tell how resistance R3 is working, as the it is shorted by conductor.

 

here is the ckt. pls tell how resistance R3 is working, as the it is shorted by conductor.

Your schematic shows R3 shorted.

Bootstrapping can be used to increase the input impedance of your darlington transistor circuit.

At the top I show a two-transistors amplifier with a common-emitter transistor driving an emitter follower:
On the left side there is no bootstrapping. The collector resistor of the first transistor cannot drive the base of the second transistor to a voltage that is anywhere near the supply voltage because the resistor's current drops as its voltage gets higher until there is not enough current to supply base current to the second transistor. The first transistor has a fairly low collector resistance so its voltage gain is low and its distortion is fairly high.

On the right side the collector resistor of the first transistor is two resistors in series. The bootstrap capacitor has a constant voltage across it so the signal drives the base of the second transistor to a voltage swing above the supply voltage. The current in the lower collector resistor is constant so it becomes a very high impedance which allows the first transistor to have a very high voltage gain and have very low distortion.

On the bottom left side I show a single emitter-follower transistor similar to your darlington emitter-follower. Its input impedance is R1 and R2 in parallel and in parallel with the high input impedance of the transistor.

On the lower right side I added a bootstrap capacitor and R3. The bootstrap capacitor has a constant voltage across it so the input impedance of the circuit is R3 in parallel with the high impedance of the transistor. R1 and R2 are not affecting the input impedance.

 

the circuit i post is not correct??

 

the circuit i post is not correct??

Yes, the circuit you posted is not correct. Audioguru even elaborated on why is it not correct and how to fix it.

Serisously, are you making fun of us all?

 

sorry, sir the circuit i post is given by my teacher in notes. i asked him also he was saying it will work.

 

Sorry, sir the circuit i postED is given by my teacher in notes. I asked him also he was saying it will work.

Which one, exactly? This thread now has 6 pages and many circuits have been posed.