71. The Wien Bridge Oscillator

This video covers the theory of operation of the Wien Bridge Oscillator and testing of a circuit. It is the second in a series of videos on various oscillators.

[@ohmedarick1]

This weekend I'm doing this The Wien Bridge Oscillator. Keep the videos coming!!!! Thank you

[@franknielsen7597]

it is the best anlyse a WB I've heard! Thank you!

[@rpsproject5349]

Great explanation of the Wien Bridge Oscillator, just the right amount of math and good images. Been trying to understand this circuit for some time.

[@TheOffsetVolt]

I'm glad you liked it. Thanks for watching.

[@karretsusu]

love the way of your explaination, thanks!

[@TheOffsetVolt]

Thank you and above, thanks for watching.

[@fer_fdi]

Best Wien bridge explanation ever! : ) Thank you

[@electronicsexplained287]

Just what i was looking for... thanks a million

[@anubisngt2825]

Thank you so much with some microcorrections at Rf/Ri network it worked just fine. Great video and explanation

[@jj74qformerlyjailbreak3]

I love your style. A Gain of +1 Sub. I’ll be oscillating around here 😂 God Bless.

[@Mrsaudf]

Very Good explanation. A big help in understanding this topic Thankyou very much

[@andymouse]

Awesome tutorial ! for me this maths is to much but with an understanding of the basics and some online calculators (and your vid !) I have been looking for the perfect 1Khz sine wave for audio stuff but I have been using a light bulb in the feedback portion of the circuit, this is a fascinating story in itself and it felt great to be using thermionics (ish) in a design. Starting on breadboard then Vero Board and now PCBs I have some good results although I don't have a Spectrum Analyser (at the moment) I have a reasonable soundcard and I have both ARTA and REW and they agree with each other ! I am waiting for the last revision of PCB to arrive and some quite expensive parts too, 0.01% for the resistors at 15K and 1% 10nF caps, this gives me about 1.06Khz by calculation. My prototype is giving me 1.08Khz at 1v PK-PK and a THD of 0.004% a little worse with noise but I have a very noisy lab ! I also found out what you mean by "don't use ceramic caps !" lol once again I love your videos....cheers.

[@abhishekshah11]

Thanks for your clear explanation.

[@TheOffsetVolt]

Glad it was helpful. Thanks for watching.

[@user-nd1be9yr8w]

Good explanation ,,, really i have learned so many thing about wein bridge oscillators.........and i liked the note when BARKHAUSEN IS HAPPY .

[@TheOffsetVolt]

Glad you liked it

[@moatacemaskar7313]

Thank you for the great video. Just I have a question how can we calculate output voltage on the paper . You've got about 16.5 V peak to peak and how to calculate that.

[@berniken6511]

love your videos I look forward to them...Thank you..............................Berni

[@TheOffsetVolt]

And thank you for watching.

[@obtron]

best vid on youtube for wienbridge

[@TheOffsetVolt]

Don't know about it being "the best" but thanks for the compliment.

[@Jay-fp8iy]

Completely agree.

[@mohandastalari391]

Sir, what is the relation in bridge being balanced and the frequency selective network

[@terencekaye9948]

Hi wanted to say thank you for this very informative video,, I'm wondering how you would make the Oscillator variable?

[@TheOffsetVolt]

Gkad you liked the video. You have two options to make a variable oscillator. You can get a ganged potentiometer or ganged capacitor. I would use a pot. Place them in the frequency dependent part of the network and you will have some variability in the frequency.

[@saarike]

Great!

[@Maceta444]

Does it adjust automatically to a certain voltage or do you have to regulate it with a pot so that it doesn't spiral into saturation like the one in your last video?

[@emiliaolfelt6370]

in this configuration it will always saturate, but if your gain is only slightly above 1 the distortion will be minimal. Some implementations include a small incandescent bulb or a thermistor in the "gain side" of the feedback loop that can, with careful consideration and component selection, function as self-adjusting gain. The idea is to select supporting components such that, when driven at the desired level, the power dissipated in your bulb/thermistor will warm it to the point of unity. Too low or high of an output will cause its temperature and thus resistance to change, thus adjusting the gain as desired. This setup is however, quite delicate, and very sensitive to ambient temperature. One solution may be to thermally couple a higher power resistor to the temperature sensitive component, and drive it via a zener diode connected to the output of the oscillator.

[@memephd2052]

Thank you m8 !

[@MrWasim100100]

nice video please make a video on schmitt trigger inverter and oscillator if possible :) you explain very nicely man :) wish you live happy, healthy and safe :)

[@TheOffsetVolt]

Thank you Wasim. There are a lot of videos on tis topic already on KZbin. Still, I'll keep it in mind for a possible video.

[@mrdarbab]

I got one working in multisim but I need a split power supply high enough. Next purchase adjustable power supply with good features.

[@BM-jy6cb]

If it has a reasonably high Q, why is the upper gain limit so critical? Why aren't the harmonics filtered out by the +ve fb network?

[@pratwurschtgulasch6662]

don't you need a gain greater than 1 to start it? what maintains the gain at 1?

[@thaddeogarcia4608]

what type of op-amp did you use?

[@arm2644]

Everybody seems to give the same speech about the Wien Bridge oscillator but nobody shows how to calculate the values of the sinewave that will be generated like the Vpp and current giving a DC input voltage rail. HOW DO YOU CALCULATE V(t) and I(t) giving a voltage rail input of V+ and V- ?

[@byronwatkins2565]

At 13:00, your fifth relation has mismatched units. The left side is admittance and the right side is impedance.

[@rj-nj3uk]

You did a lot. You should have done the derivation of "fo" too.

[@TheOffsetVolt]

Hello, I did derive the frequency for Fo at about the 8 minute point although I admit I did not show how the equation was derived. Is this what you are referring to? Thanks for watching.

[@mrjohhhnnnyyy5797]

I am a bit disappointed that you didn't mention the use of a incandescent light bulb in feedback to make it stable. Great explanation anyhow :)

[@andymouse]

I have used a 12v bicycle lamp in mine and have great results !!

[@user-qu2oz2ut2h]

my feedback is positive)

[@Jay-fp8iy]

Finally a white guy speaking English explaining this! The Indian-English explanations for this were terrible. Thank you so much. Very helpful.