Transistor........!

[koolguy]

The emitter resistor is part of the correct DC biasing of the transistor. The capacitor is added in parallel with the resistor to increase the gain of the transistor at frequencies higher than its calculated cutoff frequency.

Didn't your teacher teach you how to use a simulation program?
Here is a transistor that is properly biased. Without a emitter bypass capacitor its gain is 9 and its distortion is low. With an emitter bypass capacitor its gain is about 180 but since there is no negative feedback the distortion is extremely high.

Sorry, sir the software you have shown my teacher have not tell about it and I will download it from net, i don't have CRO so, pls tell how to watch wave in computer or other without it..!

 

[audioguru]

The simulation software I use is free from Linear Technology. Most of us use it. Download it from their website.
You can change parts values and see what happens to the waveform.

 

[koolguy]

Yes, sir i have LTspice 4 but i don't no how to use it like watching the o/p waveform so pls tell how to see waveform like transistor and rectifier circuit.

 

[audioguru]

Ask your teacher to teach you how to use LTspiceIV.
Maybe your teacher can read the HELP files to you.

 

[transistor495]

Here's a tutorial: **broken link removed**

Yet another Canadian excellence!

 

[koolguy]

thank's..!

 

[koolguy]

How to find resistance value will biasing transistor in amplifier mode, as in numerical the value are given for calculation but in actual how to calculate it resistance & capacitor in the circuit for making it ..?

 

[audioguru]

How to find resistance value will biasing transistor in amplifier mode, as in numerical the value are given for calculation but in actual how to calculate it resistance & capacitor in the circuit for making it ..?

You must learn about the basics of electronics to know how to design a simple transistor amplifier and how to calculate resistor values for biasing the transistor.
You must learn about the simple cutoff frequency calculation for selecting capacitor values for a simple transistor amplifier.
You also must learn how to speak in English.

 

[koolguy]

Pls tell how to learn this..?

 

[audioguru]

I learned about transistors in university then learned more in books. Now there are many tutorials on the internet.
You learn a lot by using a simulation program, changing parts values and seeing the results.

 

[koolguy]

ok, I will try it.

 

[koolguy]

In Multimeter Hfe option is given, teacher says it used for finding gain of transistor but when i connect transistor in it , meter shows no reading, why??

 

[koolguy]

pls, reply??

 

[audioguru]

In Multimeter Hfe option is given, teacher says it used for finding gain of transistor but when i connect transistor in it , meter shows no reading, why??

Maybe you connected the transistor wrong.
Maybe the meter is broken.
Maybe the transistor is burned out.

A multimeter measures a transistor's hFE (DC current gain), not its hfe (AC current gain).

 

[koolguy]

Maybe you connected the transistor wrong.
Maybe the meter is broken.
Maybe the transistor is burned out.

A multimeter measures a transistor's hFE (DC current gain), not its hfe (AC current gain).

I have post rating of 2N3055, pls tell how to use this rating as mark in image!!

 

[audioguru]

I have post rating of 2N3055, pls tell how to use this rating as mark in image!!

"As mark in image" does not mean anything in English. Maybe you are talking about the notes that you made on the datasheet?

The max allowed collector current of a 2N3055 power transistor is 15A. The max allowed base current is 7A. The gain is not 15/7 because the DC current gain is shown to be a minimum of 5 and typically 13 at only 10A and nothing is spec'd above 10A because then its performance is very poor.
The 2N3055 transistor will probably melt if it has 15A and 7A for longer than a short time. Then the emitter current is 22A! Its saturation voltage loss is as much as about 6V and then its dissipation is as much as about 108W.

 

[fixer72]

Hello friends , i have a problem with bu808dfx , i don't know what is this? It is like transistor

 

[audioguru]

Hello friends , i have a problem with bu808dfx , i don't know what is this? It is like transistor

Instead of barging into this thread as a hyjacker, please start your own thread and explain in details what problems you have.

 

[fixer72]

The bu808dfx is not working , i want to change it , but i don't see it in the shops ,so i want sustitute for bu808dfx ,& thank you

 

[audioguru]

MODERATOR, please get this hyjacker away from this thread.