My word, in just a few months on KZread watching videos (part time) like these I've learned more than I did at college. It's barmy how much better teachers do it for the love. Thank you!

@TheOffsetVolt

2 жыл бұрын

Wow, thanks!

Best desciption of a colpitts oscillator I have ever seen .. Brilliant!!

Great! Thanks for taking the time to do these videos.

You bought a lot of clarity to the subject for me. I'm semi-retired so learning is slower than in my 20s, but your style and pace are really helpful to me. Thank-you! A great thing about KZread is you can pause, rewind and watch again...something I couldn't do in a 1960s class room!

@TheOffsetVolt

3 жыл бұрын

Glad it was helpful!

Yes thanks for your great video presentation, and you covered the important practical aspects very well I thought, nice work..

Excellent lesson. Best on the web. Thanks much.

Great presentation. You earned my subscription after only 1 minute into the video. Great job!

Great explanation, build and demonstration of the results. Thanks for sharing.

That's an interesting way of looking at two caps in series - the two outer plates will have their distance doubled compared to a single cap since the two middle plates are connected. It seems so natural when explained like that, but I would never have thought of it myself. Nice.

excellent explanation, greetings from Colombia

I haven't finished with your video but I calculate Xc to be 23.5701 ohms for 90 nF and not 11.785 ohms which it would be if C were 180 nF. Please correct me if I am wrong. I love your videos.

This video is so informative everything is well explained

This was great. thank you!

04:50 In Germany I've only heard people refering to them as tubes (Röhren), valves (Ventile) are reserved for diodes. I really enjoy your calm and comprehensive style of presenting.

@gregorydaniel9068

2 жыл бұрын

you all probably dont give a damn but does anybody know of a tool to get back into an instagram account..? I was dumb forgot my login password. I would appreciate any tricks you can give me.

@averydonald6129

2 жыл бұрын

@Gregory Daniel Instablaster =)

This was really good. I wish I had found it earlier.

Hello! thank you for the video, that great theoretical and practical material) Tell me please, will it work well on frequency up to 30MHz if take high frequency OPAMP(for example 8009 or something like that)?

great explanation, thank you for sharing.

@TheOffsetVolt

5 жыл бұрын

Thanks you, glad it was a useful video to you.

@kolinevans9127

5 жыл бұрын

yes inspired me to check out 'multisim live' i just found it so want to play with some NPN set ups - thanks again.

Very nice we need remind ourselves how to do it : old school, 1964

You aren't good on explaining things in fact you are Excellent. Thanx a lot. Keep posting.

Very well done! I first tried this with an LM358, it has a bandwidth of around 1MHz, wouldn’t oscillate. Changed to a higher BW op amp and wala oscillations! The tank circuit would also produce a freq around 80KHz, thought the LM358 would be sufficient.?

Where do you connect the pos and neg of battery?

Mostly for experimentation... would it be possible to vary frequency through use of a (albeit unusual) variable inductor in the tank circuit? Thx.

@TheOffsetVolt

6 жыл бұрын

Absolutely. You could also make one of the caps variable but that would change the feedback fraction and you would need to adjust R1. Thanks for watching!

Thank you for a great and clear video. I have learnt so much, coming from a digital to Analogue electronics education. Is it possible to 'buffer' the output by using another Op Amp at the output of the first?

@TheOffsetVolt

6 жыл бұрын

Hello Ian, You bet, using another op amp would definitely do the trick. Thanks for watching.

*Hello good job, I like*

Great vídeo!!!! Could you do Hartley oscillator?

What is the highest frequency you could use the SA5532 op amp for in your colpitts oscillator?

@ohmslaw6856

3 жыл бұрын

Infinite Hz

Kind sir, thank you for the video and explanation. I need to ask you some fundamental questions: Does the output oscillate above and below ground or above and below some d.c voltage? I don't have an oscilloscope and am trying to read frequency off of a Klein MM700 multi-meter. I have constructed some BJT Colpitts circuits that my meter doesn't seem to read. I am thinking that because the Op -amp has a dual power supply it's output would oscillate around the ground potential? I intend to build a 10 Mhz circuit and will change caps and inductors as required, do you think a 741 op-amp is ok for this? Thanks for any help!

@TheOffsetVolt

5 жыл бұрын

Hello, It oscillates around ground. A 741 wouldn't good at 10MHz. It only has a bandwidth to about 1.5M if memory serves. Thanks for watching.

@robertschoenberg3972

5 жыл бұрын

I checked the 741 data sheet. Minimum bandwidth is .437 Mhz with typical at 1.5 Mhz. I will design for a frequency somewhere in the am band and check for oscillation on my radio. Need to buy a 'scope. Thanks for your help! I am going to watch more of your vids.

Cool

how can you find total c with the inductor between them?

Hi, nice video I really enjoyed it, can i use this circuit with an inductor load like a coil ?

@TheOffsetVolt

6 жыл бұрын

Hello and thank you for watching. It is possible to drive a coil but the op amp isn't designed to output much current - you may need a BJT , Fet, etc.

Can you scale this design to 5GHz, also can you dither the frequency by say by 100 MHz? I am considering a design with those specs.

What type of caps are those?

Sir how can we connect it on audio transmitter? Where can we put the input signal. Im just a beginner learning about electronics online😃.

How can you find the bandwidth?

could this design and op amp operate up to 850 kHz?

Hi The Offeset Volt, I simulated your circuit, however changing the gain and the R1 resistor as you have to 40k and 120 Ohm does not result in a change in the output voltage. I have also build a similar circuit and I still could not get a larger waveform, do you have any insight as to why this might be?

@koekie7003

2 жыл бұрын

After a while of using my 1 braincell I have deduced that the issue might in fact be the slew rate

The amplitude of the oscillations keeps on increasing in my circuit. What do I do?

@TheOffsetVolt

5 жыл бұрын

Hello, Try adjusting R1 up or RF down. Sounds like the feedback is a little too high.

Great teacher. I think Germans call tubes, valves.

Where vcc is attached?

why 90 ohms?

@jacquelineurena5860

3 жыл бұрын

I am wondering the same question, how do you choose the value for Rg?

where would R1 be in a single transistor version? where would it be in a single transistor Hartley oscillator (I cannot make them oscillate!)

How did you find your value for Rg?

@koekie7003

2 жыл бұрын

3x impedance of tank circuit

I doubt about the calculation on beta, it should be -1 if we include phase instead of 1/3.

@Notilix

5 жыл бұрын

Actually, I agree with you. And I can't say why it's not saturating as hell when he tries with real components

To me the capacitors are in parallel because the outside plates are both grounded. Are you using a dual polarity ps or single?

@TheOffsetVolt

6 жыл бұрын

Hello, I am using dual polarity. The ground between the two caps is the secret.

@kolinevans9127

5 жыл бұрын

so just to be clear {because there is some confusion} - when you say 'ground' you are talking about equalizing the polarity of the 'DC' input or 'earth ground' ? {i'm specifically talking about the NPN setup} - so you are sourcing that with 'standard' two polarity 'DC' so 'positive' and 'negative' which equalizes etc. ?

@arrano7087

5 жыл бұрын

The inductor discharges towards both the capacitors, therefore from the point of view of the inductor, so to speak, they are in paralell. The response of the whole RLC net formed by R1,L1,C1 and C2 can be calculated separating the net in two filters. The first one, a low pass formed by R1, C1 and C2. From the point of view of R1, C1 and C2 are indeed in parallel and the -3dB point should be calculated taking that into consideration. The second one is a resonant circuit formed by C1,L1 and C2, and here is where the capacitors are in series. This is my interpretation at least.

I think there is an error in the Xc formula if i put it in excel i get 23.57 ohm if i use 90nf value

@alhenriq

5 жыл бұрын

You’re right, he calculated the individual reactance of C1 and C2, both at 180nf. Possibly got ahead of himself.

Tried a 7mH coil... nothing..

@TheOffsetVolt

3 жыл бұрын

Sorry to hear that. I assume you were trying for a particularly low frequency. What were you shooting for?

Colpitts vs twin t opamp

pspice don't want to work _-_