How Colpitts Oscillators Work - DC To Daylight

[@castlecodersltd]

A really good video. The explanations with the calculations raise the game. Very helpful. Thank you

[@AmRadPodcast]

Thanks, much appreciated! -Derek

[@jstro-hobbytech]

I agree. I'm doing math as a hobby. I love it

[@7alfatech860]

Thanks for using the tiny connecting wires on the breadboard: makes everything so much easier to see.

[@AmRadPodcast]

Thanks. I usually lay things out with presentation following functionality. However, since I started using the overhead camera/breadboard, I'm trying to lay things out so it's easier for folks to replicate. Thanks for the feedback! -Derek

[@Judsonator]

Thank you! I loved the explanation. It really solidified previous attempts to understand oscillator feedback

[@albumalbum68]

The first and the only explanation I've understood

[@abubalo]

That background text later the left had me laughed for a second. Perhaps it is my first time on the channel and it is a good way to show off without trying. Haha 🙌

[@agnelomascarenhas8990]

Great start. Using the same baseline circuit more exploration is desirable. Loop gain can perhaps be tested by perturbing the oscillator. What sets the amplitude is worth discussing. Temperature tolerance/drift is another aspect, even with crystals. Since oscillator output is used as reference signal, its clock jitter, noise are worth discussing.

[@ammarahmed5981]

Very nicely explained component by component.

[@Unfinished80]

Thanks for another great video! You explained it very well.

[@AmRadPodcast]

Thanks James. -Derek

[@mxcollin95]

Great video! This is exactly what I was looking for. 👍

[@EricEschenbach]

What a great video! I'm looking forward to more!

[@Enigma758]

Good presentation, thank you!

[@AmRadPodcast]

Anytime! -Derek

[@L2.Lagrange]

Fantastic video, sir. I seem to have all the components on hand to build and measure this circuit, I believe I will be trying this later!

[@manuelmarquezsr8884]

Very good explanation.

[@philldonn705]

One of the reasons for the distortion might be the fact that the amplifier gain depends on re' which depends on emitter current. Considering that collector current is not constant this means the voltage is not constant too. This means the gain is higher for for higher emitter currents and lower otherwise. You should get lower distortion if you use Re without bypassing, large enough to overshadow the influence of re' but small enough to get high enough gain.

[@masterchain3335]

Fantastic explanation! This really helped me.

[@raphaelcardoso7927]

Being off by 10 kHz from 77kHz is totally justifiable by the component's tolerance. Caps and Inductors in those ranges have solid 10% tolerance, and their errors combined can easily cause this ~15% jump in f0. The frequency does not seem high enough for the pF-range capacitances in the breadboard to influence that much. Cheers and thanks for the great video

[@harikamalakarreddydarapu7410]

Excellent tutorial

[@omarosama854]

Thank you soo much for such a great explanation it really helped me out a lot!!❤❤

[@TheDefpom]

Attaching the scope probes to the oscillator directly would have affected the oscillator frequency, the best way is to use a near field probe or if that’s not possible couple in through a 1pF ceramic cap.

[@AmRadPodcast]

Good tip. Thanks Defpom.

[@AlexanderPatrakov]

I think it would have brought the frequency down, but in the video we see that the frequency is higher than expected. So it must be something else.

[@twin1q]

I built this circuit a few years ago. The transitor is going in and out of saturation so you are getting a lot of distortion from that. notice that the output of the LC is very clean sign wave. I ended up amplifying the signal at the tank. It was way better distortion.

[@SDX2000]

This makes sense. Great work!

[@justovision]

Great introduction to the key factors. I noticed your scope channel 1 was at 1x and channel 2 was as 10x. Was this intentional? Wouldn't the 1x probe further load down the tank circuit?

[@AmRadPodcast]

Justin, you are correct.. when I was shooting I didn't realize I left the probe at 1x. Doh! This is a good point, which I should have noted in the video - 1x which is useful for low frequency probing (and those that can withstand moderate loading ), should not have been used for this measurement. 10x is better for higher frequency measurements, and presents a much lighter resistive load, as well as a lower value of capacitance which could cause frequency shift. As DefPom pointed out in another comment, a simple inductive pickup coil could be fashioned from wire and used to sample the frequency - but note that mutual inductance can also load down the circuit. Nothing is simple is it?! -Derek

[@xl1803]

Super video 😄

[@amirmohammad3213]

Good luck and God the Almighty blessed you with eemaan and Divine happiness,thanks for educating us.

[@farvezfarook3422]

the output is distorted because you have set the gain with respect to re(which is a function of Ic) there is another form of bypassing where two resistors are used and one of them is bypassed with a capacitor

[@shourovpal2168]

thank you for sharing .

[@marinleguennec6848]

Question : why can we consider that the 2 capacitors are in series even if there is a connection at the base between

[@bobroberts374]

Excellent video,. Great presentation, nice job!

[@larssjodahl7660]

Great basic tutorial! Bookmarking this to rewatch next time I start building an oscillator.

[@wafiullah-shafia]

Amazing

[@JohnUsp]

Great lesson. Thanks.

[@LydellAaron]

Thank you.

[@MrSlackrick]

Great stuff. Teeny little error: the 3rd resistance in the overlay text at 12:30 should read r'e*β, not RE*β (i.e. R1 || R2 || r'e*β). This is for the same reason that the emitter-bypass changes the (open loop) gain of the common emitter to Rc/r'e from Rc/Re.

[@PhG1961]

Awesome video !

[@martindowney7915]

I enjoyed that video thank you my friend,.

[@ColossusEternum]

I'm having a hard time with being able to classify oscillators. I do understand how this one works, but occasionally I'll run across a topology in an antique radio that I fail to understand. Namely, when I find that the tank circuit is in a parallel configuration. My understanding is that with phasor analysis, at its resonant frequency the impedance of a parallel LC combination would approach infinity. Thus I would imagine that no current at the desired frequency should flow through the oscillator tube that should be providing feedback

[@johndoe-bq1xt]

I love this video, thank you !

[@surakeneni1310]

When you started the video and said a little bit about math i taught you are going to include the calculation regarding amplitude of oscillation...so say something about amplitude of the oscillator

[@michaelschweizer2115]

Good explanation! Thanks!

[@AmRadPodcast]

Thanks Michael! -Derek

[@steffanjansenvanvuuren3257]

when Q1 and R4 is not there, then you will have 1.86V over R2. But as soon as you put Q1 and R4 in parallel with R2. The total overall resistance below R1 changes, it becomes less. That means you will not have 1.86V as Vb.

[@신국헌-r6n]

선생님 전 선생님 무시하는 말이 아니니 그저 선생님 의견이 보편저 전기 전자 킷트의 확대에. 도움 되라는 말합니다.저는 기본의 전기전자는 제 남동새 어깨너머 배웠지요, 그래서 모르는 부분이 더 많으나 고등학교에서 기본의 전기전자는 다 배우더라고요 그래서 거기에 약간의 선생님의 조언과 부연 설명 매우도움 됩니다,그러나 창작자는 자기의 새로움 더 추구함 그게 더욱 진화입니다. THANK YOU.

[@maneeshyadav4936]

Thank you sir

[@jstro-hobbytech]

that was cool. building a test jig out of veroboard with everything super close would be better ehh. use sockets for the different components?

[@endaleabebekumsa7271]

Wow...Thanks!!!!

[@kamleshchavan7451]

Part 2 video is there on this topic

[@jugaltalks195]

Why should how do u consider those resistors values? Could you explain me the reason for particular values.

[@jimcrowjoe451]

How did you calculated the value for C5?

[@AmRadPodcast]

A rule I generally follow is to make the Xc = 1/10th the value of Re at the upper desired frequency. So if desired Xc ~= 120 Ohms, C = 1 / (2pi * f * Xc) ~= 1.3uF. I grabbed what I had on the bench... 1uF. in reality, it would probably be better to use 10uF, and keep Xc fairly low for the design frequency of 1kHz. -Derek

[@OussamaAbuUmar]

Hello everyone I want to make a little project so I can wirelessly (just a few centimeters) power an LED strip (just a short section) using a transmitter and reciever coil. I have a 6V 4Ah lead acid battery. I want to use this as the input. I want to convert this to an AC signal around 100kHz and connect the transmitter coil to it. On the other side I will have the reciever coil that goed to a rectifier and then to the LED strip (5V 1.9W). What is the best (and most simple) way to do this? I was thinking about using a Colpitts Oscillator. Can this work? Also is the battery ok or should I just start with a 12V voltage from a bench psu to make my life easier?

[@Dreher38911]

Barkhausen says that the loop gain must be equal to 1, and not greater than 1.

[@SuperFredAZ]

The circuit would be a little better if you put the 1 K collector resistor to the gnd side of the tank. Remove the 2uf cap and connect top of the tank with a wire and place that cap on bottom of the tank to gnd, and if course remove direct gnd from the bottom of the tank.

[@LittleGhostPro]

Isn't base voltage at the emitter only equal to VBE -0.7 when the voltage divider bias is stiff? Otherwise you need to solve Base Emitter Loop for base current and use beta values to calculate current? It works fine in this particular example because the resistor values are handpicked to avoid this calculation

[@agnelomascarenhas8990]

The oscillator operates at 77 KHz, but the amplitude regulation path has roughly 1.5KΩ and 1μF and thus approx. 100Hz loop bandwidth. Can that be the reason for the distortion.

[@smartups1]

Does anyone know the Derek KZbin channel

[@qzorn4440]

this is a wonderful Saturday afternoon cup of coffee video ☕ 🍩 would something like LTspice free stuff simulate this circuit, then PCB software to have some made? 😎 thanks a lot

[@diyfamily6848]

I like your title "DC TO DAYLIGHT", I wonder how many people actually get it ?

[@PatrickSimons79]

Would you not be better off using a real inductor in your circuit as opposed to relying on a side effect of a resistor?

[@subramaniamchandrasekar1397]

I know you are from the past. From which year are you from. How much you paid for the flux capacitor?

[@radoslavradoslavov3528]

I am 100% - you

[@ajingolk7716]

With an opamp is better

[@IftikharAhmed-up1rw]

Why not element 14 ship and accept orders from Pakistan

[@kaosthecosmicreviewer1055]

looking at the flux capacitor in the back, I guess this means that you were near the railway when the Delorean got wrecked.

[@AmRadPodcast]

You are correct! Ended up with a nice souvenir however.

[@brothertheo2677]

DC to daylight? I don't think so.

[@AmRadPodcast]

Can you clarify?

[@brothertheo2677]

@@AmRadPodcast oscillators cannot go down to dc by definition

[@AmRadPodcast]

@@brothertheo2677 I suppose the title could be misleading if you are unfamiliar... The show, or segment is called DC to Daylight - I cover subjects that span the range of DC, to optical stuff.

[@brothertheo2677]

@@AmRadPodcast Ah, Assumed it was clickbait. My bad.

[@AmRadPodcast]

@@brothertheo2677 no worries. I checked out your channel. Pretty cool stuff!

[@NIKOLAWIRELESS]

u geesed not roiginak

[@عبدالعفوهقي]

I want to oscilloscope, I don't have one.

[@JohnUsp]

There are some cheap chinese models.

[@عبدالعفوهقي]

@@JohnUsp I am from Algeria, and the prices of the cathode oscilloscope device in Algeria are approximately astronomical 11,000 Algerian dinars, and Algeria is a consumer country, not a producer, such as America, Canada, Japan, China, South Korea, Europe and others. I studied industrial electronics, I graduated in 2019 and to this day I do not have a cathode oscilloscope. Poor countries like Algeria have to suffer a lot to get simple things, even if used. Now second-hand products are coming from Europe, it is likely that their owners have abandoned them and are sold at astronomical prices while they are used. Few times you will find things that you might say are affordable and yet still be expensive. The minimum monthly salary for an employee in Algeria is $90 per month. The average salary we have in Algeria is between $200/300 per month. Poverty is very high in Algeria.

[@JohnUsp]

@@عبدالعفوهقي You can do a simple oscillocope using your Cellphone. I guess works well up to 100kHz

[@JohnUsp]

or using your PC/Laptop, search for: "diy oscilloscope"

[@عبدالعفوهقي]

@@JohnUsp To be honest, this is the first time I've heard of this information. I will try it out. Also my mobile phone is not very good Samsung A7 2017, and the computer is much weaker AMD E1, from 2015. I have another computer, very old Pentium from 2009. And I hope that the connecting wires and other requirements are not expensive. The United States of America is wide open in terms of electronics, design and development. I wish I learned a considerable period in the United States of America. Albeit short term, especially the basics.

[@ourtechwriter]

excellent×