Please help transistor amplifier

[michael1978]

lol
use google
https://www.google.pl/search?q=0.05...illa:pl:official&client=firefox-a&channel=rcs

haha i rely don't find i find one like min 0.050+10*0.050=0.55, joney were i make now mistake, with my calculator pfff i am shame

JONEY can you tell me please how to calculate in my calculator please

 

[michael1978]

Joney i know you know how to do it with calculator, can you tell me because i have in my hand calculator, i can find nothing in google the same result please...

 

[Jony130]

Simply use your brain instead of a calculator.
And if you still don't know how you should quit EE and start learn math.

 

[michael1978]

Simply use your brain instead of a calculator.
And if you still don't know how you should quit EE and start learn math.

JONEY i use me brain, why you don't tell me to calculate with my calculator, you just help me, i thank you for help, just tell me a little bit, and i use a calculator, you help so much, help also this one

 

[Jony130]

But I don't understand what is your problem?
I_R1 = 50uA + 10*50uA = 50 + 500 = 550uA = 0.55mA = 0.00055A

 

[michael1978]

But I don't understand what is your problem?
I_R1 = 50uA + 10*50uA = 50 + 500 = 550uA = 0.55mA = 0.00055A

joney i know this from begin to calculate this is easy, but my problem was other you forget,
i ask you for this

-------------------------------
o sorry joney i make you tired, i understand now, so if load current is 50μ we chose voltage divider current 10 larger then the load current, and we have

R2 = 1.7V/(10*Iload) = 1.7V/((this is 10 time larger)10*50μ(base current)) = 1.5V/500μA = 3.4K this i understand

but this i don't understand
I_R1 = 10*Iload + Iload = 11*Iload = 550μA

10*Iload(50μA)+Iload(50μA)=11(how we get 11 now)*Iload(50μA)=550μA

i don't understand that 11 how we get? 10*Iload(50μA)+Iload(50μA)=0.55 not 11 sorry i don't know where i make mistake, where come this 11, i don't know how to calculate, i know 11*Iload is 550μA
thnx for answer
----------------------------------
joney this 11 is my problem

 

[Jony130]

OMG
Look here
We have this equation
B = 10*A + A = 11*A
The first part tell as that we have a ten apples and we need add one more apple.
So we end-up with eleven apples .

 

[michael1978]

OMG
Look here
We have this equation
B = 10*A + A = 11*A
The first part tell as that we have a ten apples and we need add one more apple.
So we end-up with eleven apples .

ah you mean so
10*0.0.5+0.0.5=
10+0.5+0.5=11

you mean like this

 

[michael1978]

ooh joney boy, i make again mistake of is right, ooo thank you try a lot to explain me

 

[Jony130]

In our cases we have 11 apples
B = 10*A + A

And apples are equal to 50uA of load current.
So we substitute for A = 50uA
B = 10*50uA + 50uA = 550uA
And this is equal to 11*A = 11*50 = 550uA
the 11 tell as that the R1 current is 11 times large the load current.

 

[michael1978]

In our cases we have 11 apples
B = 10*A + A

And apples are equal to 50uA of load current.
So we substitute for A = 50uA
B = 10*50uA + 50uA = 550uA
And this is equal to 11*A = 11*50 = 550uA
the 11 tell as that the R1 current is 11 times large the load current.

thank you joney for losing time for me and help i go to sleep tomorow work have a nice sleep

 

[michael1978]

thank you ver much joney now i start to understand

 

[michael1978]

thank you ver much joney now i start to understand

hi joney, may i ask you something

if we take 10 large then load(50micro)this is all time formula
for i_R2=10*LOAD and I_R1 = 10*Iload + Iload = 11*Iload = 550μA
and
if we take 5 large then load(50micro)this is all time formula
for i_R2=5*LOAD and I_R1 = 5*Iload + Iload = 11*Iload =
is correct?

and can you tell me which book, do you know some book where i can learn good electronics?
advice
now i am reading electronics principles 7 by malvino

 

[Jony130]

if we take 5 large then load(50micro)this is all time formula
for i_R2=5*LOAD and I_R1 = 5*Iload + Iload = 11*Iload =
is correct?

Check your algebra skills because your answer is wrong.

B = 5A + A = ??

and can you tell me which book, do you know some book where i can learn good electronics?
advice
now i am reading electronics principles 7 by malvino

I don't know any good book. Try buy a book in your native language.

 

[michael1978]

Check your algebra skills because your answer is wrong.

B = 5A + A = ??



I don't know any good book. Try buy a book in your native language.

is 6 i know now,

but the best books are in engish

 

[michael1978]

CAN I KNOW, which electronic software you use

 

[michael1978]

joney my dear, are you here somewhere, i just wana say thank you for help, losing time for me...

 

[Jony130]

but the best books are in engish

I don't think so.

CAN I KNOW, which electronic software you use

I use LTspice, but circuit simulations are not good for beginners.
Circuit simulators are worthless, or worse, if you don't understand your circuit pretty well before you simulate it. Still, it won't hurt you to play with it, so long as you always keep in mind that garbage in = garbage out, or, in the case of simulators, garbage in=sophisticated garbage out.

 

[michael1978]

I don't think so.

I use LTspice, but circuit simulations are not good for beginners.
Circuit simulators are worthless, or worse, if you don't understand your circuit pretty well before you simulate it. Still, it won't hurt you to play with it, so long as you always keep in mind that garbage in = garbage out, or, in the case of simulators, garbage in=sophisticated garbage out.

but i don't understand, i have to do experiments, and i don't have all instruments, in electronics simulator you have all instruments, but me i try examples, but you know better i see you have experience.
thx for answer

 

[michael1978]

thank you very much

joney is correct this amplifier, he give voltage gain of 44mv not 50mv

 

[Jony130]

joney is correct this amplifier, he give voltage gain of 44mv not 50mv

I don't know. You need to tell me the bias point collector current and BJT model that you use.

 

[michael1978]

I don't know. You need to tell me the bias point collector current and BJT model that you use.

--------
this your example i just simulate (do you see the foto the value) in quote 69

Vb = Ve + Vbe = Ic*(Re1+Re2)+ Vbe = 5mA* (180 + 14) + 0.65V = 1.62V

If we assume Hfe = 150 I (I use transistor 2N3903 I don’t know other there are a lot of types)

Ib = Ic/hfe = 5mA/150 = 34μA

R1 = (Vcc - Vb)/( 11*Ib) = 22KΩ

R2 = Vb/(10*Ib) = 4.7KΩ
Re1 = Rc/Av - re = 1K/50 - 5.2Ω = 20 - 5.2Ω = 14Ω

 

[Jony130]

But your circuit is different than mine. Also you can read from simulation DC collector current.
And your circuit has a voltage gain equal to:

Av = Vout/Vin = 44.33mV/2mV = 22.165[V/V]

My example look like this:

And has a voltage gain Av = 45.8V/V But we can easily change the voltage gain by changing the Re1 resistance.

 

[michael1978]

But your circuit is different than mine. Also you can read from simulation DC collector current.
And your circuit has a voltage gain equal to:

Av = Vout/Vin = 44.33mV/2mV = 22.165[V/V]

My example look like this:

And has a voltage gain Av = 45.8V/V But we can easily change the voltage gain by changing the Re1 resistance.

---------
can you explain how you can change the voltage gain by changing Re1
------------------
Joney do you remember i ask you to make one amplifier with voltage gain of 50, only we Re1 Without Re2,

and you show me this example, look at quote 66, IF YOU HAVE TIME.
Re1 = Rc/Av - re = 1K/50 - 5.2Ω = 20 - 5.2Ω = 14Ω, and i think you did not show me complete example, becuse i am searchin here but i can't find,
do you remember now Re1 = Rc/Av - re = 1K/50 - 5.2Ω = 20 - 5.2Ω = 14Ω
for the rest value i think of maybe i misunderstand , are the same like this circuit the last one... if not ? PLEASE CAN YOU MAKE ONE EXAMPLE ONLY WITH Re1 PLEASE THNX

 

[yungman]

I did not read the whole thread. Remember when I left off, I showed you how to calculate the gain? It's the impedance seen at the collector divided be the impedance seen by the emitter? Adding C2 don't change this, the total emitter resistance is

r'e+ Re1+(Re2//Xc2) where X_{C2}=\frac 1 {j\omega C}

You change the Re2, you change the impedance on the emitter side and change the gain.

You need to get the solution manual of Malvino and work through the problems one by one. I thought I left you in good hands already. There comes a point of time you just work on the problems one by one and struggle through it. You are spending too much time writing posts here instead of working through the problem in the book. These questions are in the book.

 

[michael1978]

I did not read the whole thread. Remember when I left off, I showed you how to calculate the gain? It's the impedance seen at the collector divided be the impedance seen by the emitter? Adding C2 don't change this, the total emitter resistance is

r'e+ Re1+(Re2//Xc2) where X_{C2}=\frac 1 {j\omega C}

You change the Re2, you change the impedance on the emitter side and change the gain.

You need to get the solution manual of Malvino and work through the problems one by one. I thought I left you in good hands already. There comes a point of time you just work on the problems one by one and struggle through it. You are spending too much time writing posts here instead of working through the problem in the book. These questions are in the book.

thnx for reply, i don't know where to get solution manual by malvino, til now i am to transistor amplifier, but i don't get nothing what joney explain me til now

 

[yungman]

thnx for reply, i don't know where to get solution manual by malvino, til now i am to transistor amplifier, but i don't get nothing what joney explain me til now

Ha ha! I always gone on the internet and look for free download. You have to do some leg work. I yet to encounter a book that I had not manage to download the instructor or solution manual free yet. This is such a popular book. It is very important to have the solution manual to learn, they show you the steps to get the answer. Now put in your effort and try working out the answer before you peek into the solution manual!

Make sure you get the correct edition, if you manage to download a version you don't have, go on Amazon and find a used textbook of that version. They are very cheap used. I went on Amazon to look for one for you just now and can't find one cheap at the moment. In fact I just ordered a copy of Malvino a few minutes ago just to keep it in my library collection because it's that good. I only paid $US 8.00 including shipping! But you can go on Amazon later and see whether they have a copy cheap.

 

[michael1978]

Ha ha! I always gone on the internet and look for free download. You have to do some leg work. I yet to encounter a book that I had not manage to download the instructor or solution manual free yet. This is such a popular book. It is very important to have the solution manual to learn, they show you the steps to get the answer. Now put in your effort and try working out the answer before you peek into the solution manual!

Make sure you get the correct edition, if you manage to download a version you don't have, go on Amazon and find a used textbook of that version. They are very cheap used. I went on Amazon to look for one for you just now and can't find one cheap at the moment. In fact I just ordered a copy of Malvino a few minutes ago just to keep it in my library collection because it's that good. I only paid $US 8.00 including shipping! But you can go on Amazon later and see whether they have a copy cheap.

i can't find, but is safe amazone site? can you order it with facture? of only with card

 

[michael1978]

---------
can you explain how you can change the voltage gain by changing Re1
------------------
Joney do you remember i ask you to make one amplifier with voltage gain of 50, only we Re1 Without Re2,

and you show me this example, look at quote 66, IF YOU HAVE TIME.
Re1 = Rc/Av - re = 1K/50 - 5.2Ω = 20 - 5.2Ω = 14Ω, and i think you did not show me complete example, becuse i am searchin here but i can't find,
do you remember now Re1 = Rc/Av - re = 1K/50 - 5.2Ω = 20 - 5.2Ω = 14Ω
for the rest value i think of maybe i misunderstand , are the same like this circuit the last one... if not ? PLEASE CAN YOU MAKE ONE EXAMPLE ONLY WITH Re1 PLEASE THNX

hi joney, can you answer me please, because i learn it in serie with Re2, and also in parallel, just with one resistor no i did not learn it, can you take a little time to show me this example, voltage gain 50 with one reistor,like other examples

 

[yungman]

i can't find, but is safe amazone site? can you order it with facture? of only with card

I use Amazon ALL the time, The used books are so cheap. I buy so many textbooks, but I never bought them new. When they said the condition is good, it is good. I have two VISA/Mastercard, I use one for everyday, the other JUST for online order like Amazon. So I can track transaction clearly every month. I never have problem.