Log and Antilog Amplifiers Explained | Applications of Log and Antilog Amplifiers
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- Опубликовано: 29 сен 2024
- In this video, the log and antilog amplifier circuits using op-amp and their applications have been discussed.
The following topics have been covered in this video:
0:22 The applications of log and antilog amplifier
2:24 Log amplifier circuit using the diode
6:48 Antilog Amplifier circuit using the diode
9:50 Log Amplifier circuit using a transistor
13:26 Antilog amplifier circuit using a transistor
16:48 Practical Log amplifier circuit (Temprature compensated Log ampliifer Circuit)
Applications of log and antilog amplifier:
The log and antilog amplifiers are very useful in the analog computer. Using these amplifiers it is possible to perform the mathematical operations like multiplication, division, and finding roots and power.
These circuits are also useful in signal compression. (For enhancing or reducing the dynamic range of the signal)
This video will be helpful to all students of science and engineering in understanding the log and antilog amplifier circuits and its usefulness in various applications.
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The timestamps for the different topics covered in the video:
0:22 The applications of log and antilog amplifier
2:24 Log amplifier circuit using the diode
6:48 Antilog Amplifier circuit using the diode
9:50 Log Amplifier circuit using a transistor
13:26 Antilog amplifier circuit using a transistor
16:48 Practical Log amplifier circuit (Temprature compensated Log ampliifer Circuit)
The black screen gives less stress to eyes, your explanation is crystal clear. you are an exam saver.
Sir, what is being written in your video in English, it is covering your formula. Because of which I can not see and I am having problem.
Please turn off the subtitles in the video settings.
❤️❤️❤️❤️
I learned a lot. Thank you so much, sir. I have a request.
Upload the design of temperature compensated Antilog amplifier if you don't mind.
Thank you, sir, you saved my day before the exam
Why is the ideality factor for Transistor =1 ?
Upload the deisgn of temperature compensated Antilog amplifier?
In input amplifiers just flip resistor with BJT, and make them PNP transistors. :)
@@movax20h thanx bro
@@movax20h AND DO I HAVE TO CAHNGE THE BJTS TOO
AND WITH WHAT
@@movax20h tq soo much bruh...
Another excellent explaination. I do not see this circuit mentioned to much in the industry, maybe replaced by software?
It is still used in many applications requiring very high dynamic range and ratiometric measurements to reference, i.e. in spectrophotometry, densitometry, ultrasound measurements, RF power measurements for research and automatic gain control loops, some PID control applications, etc. It can also be used in audio and video applications (noise reduction, transmission, recording, effects, etc), where it is commonly called "compression". In some situations it is also used as a stage before low-bit ADC, as an alternative to costly high-bit ADCs.
Crystal clear explanation !Please upload the design of temperature compensated Antilog amplifier.Thank you.
Thank you soo much sir, this is what I was searching for
Ktu കാർ ഉണ്ടെങ്കിൽ ഇങ്ങോട്ട് വാ💪💪
But why you have not considered R2/R1 of Subtractor output?
If the resistors R1, R2, R3, and R4 are selected properly the output of the difference amplifier will be Vb- Va. I have already explained that in the earlier video of op-amp has difference amplifier. That's why I didn't mention it here explicitly. I hope, it will clear your doubt.
@@ALLABOUTELECTRONICS Yes sir, I understood. Thank u
good question
Great explanation. Please upload the design of temperature compensated Antilog amplifier. Thank you.
In the OP AMP LOG formula the reverse current appears. However, the reverse current is not a constant value and follows a curve, albeit with a small slope. Measuring the reverse current of a diode, I found values ranging from 1 microampére to about 10 microampére. If current is not fixed, how can I enter it into the formula?
Sir,plz provide ckt for temperature comensated antilog amplifier (as it cannt be constructed just by interchanging the position of resistor and transistor)
Can you please upload the vedio for temperature compensated antilog amplifier
Sir, please show us circuit and calculations for the Antilog Temperature Compensated Circuit, I need to cancel out the Reverse Saturation Current term
Sir , how temperature dependent resistor manage the thermal voltage ??????
Why in antilog amplifier a pnp transistor is used and in log amplifier a npn transistor is used??
Was there ever a video made about the anti log circuit that is not temperature dependent?
Sir, what happens if I short the base and collector of the transistors?
Osum video😊very good explanation 😍my doubt is clear sir!! 🙂
Nice video.
I am trying to understand a logamp example in LTspiceXVII. It is simple partially temperature compensated circuit, but it doesn't have third differencing opamp, and one of BJTs is in transdiode config, and another one is not (shorted B and C). Additionally there is reversed diode. (Plus some caps, probably for stability control). I did run it, and adapted, and well, it does' work, but I am not sure why :D
Hey how can I linearize GP2Y0A21YK0F Ir measuring sensor with log amplifier please help
Do you mean R5 is ptc resistor so when temperature increases VT value increases and R5 increases to adjust VT
This theory is ok, but it will be ok, if you took actual values of components and showed the output, it will be better.
very nice video - but so what of log amplifier - this more than just an academic exercise
are bhai ground ke place pr har baar common use kr rha h
Good video thank you, and a correction it is pronounced as 'Divishion' not 'Divison', it is 'shion' not 'son'. Hope you get it right next time thanks.
hey, that's just his accent. It's rude pointing it out like that -_-
@@kartikeyak3425 No it's called proper pronunciation, it is not something you should ignore by hiding behind an accent. When he speaks hindi let him speak it well and the same for english with proper pronuncation. It's not rude.
When we designing log amplifier,there would case of diode going into reverse bias as bcz pside is connected to zero and nside connected to vout then the diode will be in reverse bias na then there would be no forward current.then how can that ckt is used as log amplifier.plz clear my doubt
Upload practical and project based on electronics also, it will increase your subscribers and will be helpful.
I like to work with you sir
informative
What is reverse saturation current value for 1n4007...???
at 11:28 can someone please clarify how vout=-vbe plz
By applying the KVL, you can get that relation.
Theory you have explained is much better. Thanks.
Respected sir, At 13:26 what is the dynamic range of circuit and how it is depending on ñ value
Plz upload the temperature compensated antilog amplifier ckt
Thank-you for the lectures i have successfully cleared my backlogs
Sir explain compensating techniques to with stand for high transient currents for a basic op-amp using mosfet with equations?
how come V_out is equal to (-V_d) ?
kya padate ho sir
Can you explain the experiment practically.....and I want set of readins.
Did you created a video for compensated anti-log ?
Why is the ideality factor for transistor is 1?
Can u please show me the diagram of temperature compensated antilog amplifier
Temperature compensated Antilog amplifier
SImple and good explanation. Thank you.
nice sir
please make videos about BJT and MOSFET. my semester final is knocking at the door..
I am going to make series of videos on analog electronics. So it will be get covered in it.
Sir, jo circuit diagram 18:30 pe dikhaya jaa raha hai usme Right se 2nd circuit Differential Amplifier nahi hai.
Reason:-
Differentaial Amplifer mein ek capacitor inv.. Ya ek non-inv... Terminal mein series mein jarur hota hai.
What I meant to say is, it is the difference amplifier, which will amplify the differential input. (The difference between the two inputs). What you are saying is the differentiator, where the op-amp is used as the differentiator circuit. I hope, it will clear your doubt.
12:6 why we don't write eta
Please upload temperature compensated antilog amplifier.....please
Use the circuit at 16:50 but replace the input amplifiers with the circuit from 14:06.
(Swap resistor & transistor positions, and change transistor to PNP)
thats great... thanks a lot.
Nice videos. Helped a lot..!!
Thanks.
Sir can u plz provide relevant questions for better practice in pdf form...
I used to post the relevant question from the previous videos in the community post.
Please check the comminity tab section of the channel for more questions.
for anti log amp. our teacher has said Vo= -Is/R Ln^-1(Vi/nVt).Its really pleasure if u would explain this
There must have been some mistake while writing. Vo= -Is*R e^(Vin/nVt) is the correct way to represent the output of the anti-log amplifier. Please confirm with him/her once again.
@@ALLABOUTELECTRONICS sure
Thank you, I know this is an old video but I am very happy you have given us this resource for when it's needed. Will watch for the antilog version and also you difference amplifier videos now!!
Hello Sir, Its much informative for me but i am still confused regarding the selection of R5, please give some more explanation about R5.
it is a temperature dependent resistor which changes its value as you change the T. Just like Vt(tehrmal voltage). As Vt increases linearly with temparature from the realtion Vt=kT/q, R5 will also increase hence compensating Vt.
your welcome
12:00 y didn't mentioned ideality factor n in Ic formula
I didn't know about ideality factor
Very nice explanation sir
That was excellent. Well done, dude!
Which transistor is used
your great work helped me in my project work .thanks a lot
sir what will happen when we connect voltage at non inverting terminal
Definitely, it will not behave like a log amplifier but it will behave kind of precision half wave rectifier.
okay thanku sir
Is it same as Log Domain multiplier or not?
Yes it will work similarly.
Does this actually work? Every circuit I've seen has failed in several simulations and actual circuits, are there specific diodes or transistors that need to be used?
It works more perfectly when the op-amp and transistor or diode is integrated on a single chip. With external diodes and transistor, the circuit works approximately. (Accuracy of the result will be poor)
@@ALLABOUTELECTRONICS Weird, I used a LM358 and a 1N4148 diode but it didn't work, I also tried using a PN2222 transistor which didn't work either, it sort of worked when I added a resistor to power but that's it. do I need to bias the non-inverting input? If not what would you recommend I try?
Have you calculated the expected voltage ? And what voltage at the output you were getting ?
First, just calculate the expected output voltage based on your voltage, resistor. From the data sheet, you can approximately take the value of Is. For 1N4148, around 1 nA. And calculate the output voltage. And then in actual circuit, check what you are getting.
You can also use the multisim simulation.
@@ALLABOUTELECTRONICS I am using a 1Kohm resistor, so (If I did my math right) I should be getting an output voltage of about -0.36 +0.026ln(Vin) but I don't get any voltage on the output of the circuit. I get something resembling a logarithmic function when I use a transistor with a 10Kohm resistor at the base connected to power.
@@ALLABOUTELECTRONICS So I've been running a few experiments with the log amplifier circuits. The first was reversing the direction of the 1n4148 diode, this surprisingly worked, it output the logarithm of the input, however it only did it half of the cycle. The other thing that I tried was using the transistor design, this one worked but only when the base of the transistor was connected to V+
Thank you for your help sir
Some questions on this topic
I really liked the explanation ✨✨✨✨
Brilliant
when will upload the next topic of opamp
Many of you wanted the videos on analog electronics, particularly on the diode, transistor (BJT, MOSFET) and other topics so I am going to cover it first.
The video will be most probably uploaded today.
Will this work for sinusoidal inputs
Yes but only for positive side of sinus u can add some offset
Very well explained
aap sir ckt design bahut acche se batatte ho
aise hi batate raho sir
thanks sir
sir apka email id mil sakata hai
thoda designing ke bare me janana tha
@@nikhilsahu9039 bhai agar mail mili ho toh mujhe bhi send kar diyo
THANK U SO MUCH SIR
Very well explained
Sera sir....... I love it.....
thank you
antilog ka b daal dijiyena sir
Its same. U just have to replace resistors with bjts and bjts with resistors and make pnp npn and npn pnp correspondingly
Nice sir
How to find Is
The value of reverse saturation current is usually given in datasheet for the given diode. For silicon diode, it is typically in the range of nA.
@@ALLABOUTELECTRONICS I have seen some circuits use a reverse bias diode to discharge a capacitor. I takes a long time.
Ab to hogya paper😂
😂😂😂😂😂😂
@@anikettomar3153 lol you guys are such losers
bhai thoda lete ho gae video uplaod late kia exam toh mera 3 din pahele ho gya IC ka
Hindi me bhi samjha diya kro
Hindi medium wale kya kare.....😥
Gaand mara