Colpitts Oscillator Explained
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- เผยแพร่เมื่อ 7 ก.พ. 2025
- In this video, the design and working of Colpitts oscillator have been explained with derivation and example.
By watching this video, you will learn the following topics.
0:30 Introduction to LC Oscillator and working of LC tank circuit
5:13 Colpitts Oscillator using the transistor (BJT) and op-amp
7:04 Derivation of frequency for Colpitts Oscillator
14:39 Example on Colpitts Oscillator
16:52 Applications of Colpitts Oscillator
What is Colpitts Oscillator:
The Colpitts Oscillator is one type of LC oscillator, where the LC circuit is used in the feedback path of the oscillator for the frequency selectivity.
As it uses the LC circuit, this oscillator can be used in the RF frequency generation.
The Colpitts oscillator can be designed using either transistor (BJT or FET) or op-amp.
In this video, the design of Colpitts oscillator using BJT and op-amp has been discussed and the equation of the frequency oscillation has been derived.
Application of Colpitts Oscillator:
1) High-Frequency signal generations (20 kHz to 100s of MHz)
2) Radio and mobile communications
3) As Surface Acoustic Wave (SAW) resonator
This video will be helpful to all the students of science and engineering in understanding the design of
Colpitts Oscillator.
The link for the other useful videos on Oscillator and Multivibrators:
How Oscillator Works
• How Oscillator Works ?...
RC Phase Shift Oscillator
• Wien Bridge Oscillator...
Wien Bridge Oscillator
• Wien Bridge Oscillator...
What is Multivibrator?
• What is Multivibrator ...
#ColpittsOscillator
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Music Credit:
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The timestamps for the different topics covered in the video:
0:30 Introduction to LC Oscillator and working of LC tank circuit
5:13 Colpitts Oscillator using the transistor (BJT) and op-amp
7:04 Derivation of frequency for Colpitts Oscillator
14:39 Example on Colpitts Oscillator
16:52 Applications of Colpitts Oscillator
how to design output wave amplitude
Can u make a video on Hartley oscillator ?
Please make a video on Hartley oscillator
Sir pls make a video on Hartley oscillator.
@Davion Augustus No problem xD
Thanks sir and your way of teaching is awesome.dont bother the comments on your accent .english is just a language.Your knowledge is very good.keep it up
The best colpitts oscillator tutorial i ever came across! thanks
Thank god people like you exist!
thanks a lot friend you've helped me understand more than any of my teachers did.
How'd the rest of your studies go?
@@PunmasterSTP I passed all of this semesters exams!
@@slayvirgins2048 Congratulations; I'm glad to hear it!
@@PunmasterSTP thanks a lot!!
You rules.
I learned from this video more than in school.
So, thanks.
Thank you. It must take a lot of time to put this teaching aid together. Well done 👍 keep going on my friend 🙏
Sir please please make video on Clapp and Hartley oscillator also..
Super brother. You are teaching very well. Life is interesting. I am from Tamil Nadu, Chennai.
Great explanation and animations 10/10
Sir please make a video on HARTLEY OSCILLATOR
Thank you sir ... Made it so easy to understand....
Colpitts Oscillator? More like "Cool video; you're a great narrator!"
Thanks Now I understand why I shouldn't have chose electronic circuits and systems.
Awesome as usual
Thank you brother for sharing gud demonstrated thanks god bless you
Q1 ) To design a Colpitts Oscillator Oscillating frequency is 5KHz and capacitor equivalent is 30 nF and feedback fraction ( C1/C2 =1/20 ) or ( C2=20 C1), calculate:
I need an explanation of an Hartley Phase Shift Oscillator ? Have you made video on that. If you've done on that topic please share link regarding that.
Sir u made our electronics so easy.. Thank you so much .. Can u pls make a video on Hartley oscillator too it will help us to know about oscillators more.
You>>>>>My teacher
Use arrow Mark to show the path way of the flow of current and parts which your telling about for clarity
Awesome video. Thanks!
wel explained sir,thanks
بارك الله فيك
Design a FET colpitts oscillator with fixed frequency specification: Design an oscillator with components c1=750uF c2=2500pF and L=40uH
Elements tolerance values should also be considered
very well explained
Good presentation .
Thank you very much for your excellent lecture. One question I have is that I thought B = C1/(C1 + C2) since B = Z2/(Z1 + Z2). ?????
Excellent
Would be great if you could also cover non harmonic oscillators, square and triangular especially.
I have already made videos on how to design square wave.
You can check videos on astable multivibrator using op-amp and 555 timer.
Here are the links:
th-cam.com/video/T7T3At9N9dk/w-d-xo.html
th-cam.com/video/iJYm_BGqa1A/w-d-xo.html
Soon I will cover the videos on the triangular wave.
here A is open loop gain of opamp which is very high and feedback fraction beta is small compare to A
so how A×beta is 1 for satisfaction of proper oscillations
Please check the example at 14:44. You will understand it.
thanks sir
Thank you sir
Make a video about class B push pull amplifier . All sub topic
Make a video on Hartley oscillator
Please make video on hartley i have exam next week please thank you so much... You are doing great work for us
Arre yarr exam me hartly hi aagaya 😭😭😭
sir,can you explain the design using BJT because nobody explaining that,just using some standard values.
could you explain this oscillator with bjt including the bias explanation
Nice video. I got a question: for the oscillator to get started, you said the loop gain should be greater than 1. However, once the Rf/R1‘s value is fixed, the gain of OPA is fixed, so how is it to achieve loop gain being greater 1 during starting and loop gain being 1 during stable period?
Practically, you need to keep the gain slightly more than 1 to get the oscillation.
Using variable resistor in the feedback of the op-amp, the gain can be adjusted slightly more than 1. If it is too high, the output will get saturated.
Using variable resistor it is possible to set it to optimum value.
@@ALLABOUTELECTRONICS Thank you, sir.
Why is there no video on Hartley
thank you so much sir
Sir, please upload more engineering videos.
hello. I am a student majoring in electronic engineering in Korea. The waveforms of the Colpitts circuit implemented with pspice and the Colpitts circuit implemented with a breadboard are different. Do you know why? And the waveform of pspice is the same regardless of whether R1 and Rf are present. Do you know why?
The p spice model will not take into account all the effects, that you will encounter in the actual circuit. And that is why you are not seeing the change in the output even after changing the Rf and R1.
@@ALLABOUTELECTRONICS Thank you for answer. Can I ask one more thing? I looked at the pspice circuit diagram on the internet and implemented the same thing on my computer's pspice, but do you know why the waveforms are different?
Make a vedio for Hartley oscillator please
sir,can u explain transistor as a ampilfier video
Can you explain opamp internal working
Sir could you explain how z1 and z3 are series connection ? 8:48. Thank for your helping.
Since for ideal opamp as no current is flowing into opamp terminal, the same current will flow through z1 and z3. Hence, they are connected in the series. I hope it will clear your doubt.
Thank you Sir. Thank for lessons. You are very good teacher.
@@ALLABOUTELECTRONICS then shouldn't the same current be flowing through z2 as well.. since the current doesn't branch out to the op amp input terminal?
sir, if we choose the value of inductor is 2.2nh then what is the value of both capacitor.
ما آمدیم تو ی یوتوب یک چیزی یاد بگیریم عملی ولی شما از روی کتاب همینطور می خوانید. کمی عملی کار کن مدار را تحلیل کن ساده و عملی ...نمیخواد مدار رو حقیقی بسازی فقط آروم توضیح بده .ممنون
when constructing variable frequency oscillator which one is better colpits or clapp oscillator
The Colpitts oscillator is better.
@@ALLABOUTELECTRONICS can you please explain ?
I don't understand how the signal being fit into the amplifier have a phase of 0
sir i need designation of an oscillator of frequency range of 5 khz to 28 khz.. it may be any type of oscillator but should be with proper derivation for frequency..sir could you upload a video of the very oscillator ??????
thanks in advance
sir during derivation of frequency,we made sure no input current flows to amplifier,then how the feedback reaches the op amp??
the feedback signal is the voltage signal, the voltage across the two terminals of the op-amp. And as there is ground between the Z1 and Z2, so there is a path for current to flow.
I hope it will clear your doubt.
@@ALLABOUTELECTRONICS thanks a lot sir,it is clear.
Can I build an inductance meter with this circuit? I if use an op amp voltage follower, set c1, c2 = 1uF, I should get L = w^2/2. I can easily measure frequency with a multi meter and reverse calculate the inductance.
In principle yes. But for every new inductor, you need to measure the resonant frequency. And manually calculate the inductance.
@@ALLABOUTELECTRONICS Thanks for the kind reply. Do I need to adjust the gain every time for a new inductor? does keeping a high gain amplifier work across different inductors ?
I think you just don't need to adjust the gain everytime
what is chaos and hyperchaos in coupled colpitts oscillator? help please
Thank you engineer ...Is it possible to build this circuit transmitter in the test panel and the special telephone landlines
thanks
Why C2 Has an effect over the circuit? If Its in parallel with the output of the OpAmp.
C2 is not alone. C1 and L are also there in the feedback network. And effectively they all act as the frequency selective elements. (As I mentioned during the derivation through circuit analysis)
sir plzz tell using h parameters
where is hartley oscillator video?
Hey friends welcome to the TH-cam channel §|§§••§•§|∆
Why R1 & R2 vanished while deriving the resonance frequency?
Cuz in high frequency, these two resistance are basically ignored as well as contributing little to resonance frequency.
How to find the amplitude
Plz also make videos power amplifier.
Please I have a question.
What is the value of L usually!!!
please reply soon🙏🏻💙.
Typically in mH.
how to know value of L and C whrn u only know freq..
Another excellent presentation. One question, why is the feedback fraction C2/C1 when the total output is across C2 (vout to ground)? I would think since it is partial feed back it would be C1/C2
I have derived the expression of feedback fraction at the later part of the video. (7:04 to 14:30)
If you go through it you will get it that why feedback fraction is C2/C1.
The value of reactance of capacitor is 1/wC(w is omega). So you can simplify the expression that is Vo/Vf=(reactance of C1)/(reactance of C2).
u will find why it is the case
Where is Hartley oscillator
You have astonishing good explanations here. But your un-rhythmic English makes it extremely hard to follow and stay focussed.
sir here is Av the open loop gain of opamp ????
No, it is the closed loop gain of the op-amp.
@@ALLABOUTELECTRONICS sir why here closed loop gain is used ?
Make video Multisim software..
As there is no video on TH-cam regarding these kind of softwares.
Make asap
At least Be polite about it
Better say slow
Please sir, I would like to order a large pepperoni pizza, extra sauce. Thank you
whaaaatttt?????
That accent is hard
A decent microphone might help a lot!
Ceq = C1 + C2 not C1C2/(C1+C2)
Bcoz That two are in series
If you r wright .... Than your diagram is wrong
To much bass in the audio.... and unwanted room resonances, making the accent even harder to discern....
Why r u in a rush please explain in a decent pace , it is like that u have to go to toilet and for that u r in a rush.....don't do this
No way, I can't understand 5 out 6 words he's saying.. Click..
Tumi akti gan**
Try subtitles Einstein
Would be much more useful if you could speak English.
Unfortunately the accent is very thick with lots of strange inflections. Too bad you can't have user-submitted dubs. Just having the content repeated by someone with a neutral accent would be helpful.
Would be much better if you could stop complaining. Go to an English youtuber , if you are so concerned about his accent.
how to generate oscillations for smps ?
Thankyou very much sir.