Low-Cost Alternative to a Function Generator: The Bubba Oscillator by Phillip Johnston. 4 March Introduction. When testing the functionality of a circuit or . Bubba Oscillator. 0. Favorite. 4. Copy. Views. Open Circuit. Bubba Oscillator. Social Share. Circuit Description. Graph image for Bubba Oscillator. Solved: Hi there. I’m trying to make a sine wave inverter based on “Bubba Oscillator”. The output of the bubba oscillator is a nice sine.

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Set more time for the simulation. Just to add yet another post on this. Home Questions Tags Users Unanswered.

Bimpelrekkie – that is not the case. By real op-ampsdo you mean finite gain op-amp? Sign up using Facebook. But oscillatr will probably result in a distorted sinewave. What is needed is a limitation on the output voltage. And this below is my result Simulated for 10sec: Insert that limiting circuit in parallel with one of the capacitors.

Trevor Yeah, strangely enough this oscillator relies on the non-ideal properties of the opamps. In the article about the Bubba oscillator the author uses real opamps. It needs a voltage contolled component which has oscilllator gain, attenuation or resistance.

I suggest reading about the Barkhausen stability criterion. And that means the loopgain becomes smaller. The simulation will be stopped. That would be gr Email Required, but never shown. Here’s the output from LTSpice: Your misconception comes from the fact that you first have to understand the theory of operation of oscillators.


Here’s a circuit that should actually work, using a quad LT and a single power supply rail: This is what is causing an exception And that will result in a stable amplitude. So the solution to your problem is: Sign up or log in Sign up using Google. Oscillayor is not that easy to model I know, I have tried.

The controller searches the right gain continuously but has osciplator inertia which prevents the distortion of the sine pulses.

Better would be to ozcillator a tanh x like function so that it limits but in a continous way. It has started to oscillate.

bubba oscillator

However when the loopgain remains higher than 1 the amplitude of the oscillation will increase and keep increasing. That’s what your plot shows.

Sine generator – Bubba Oscillator Ask Question. Unfortunately I havent Matlab nor Simulink, only washy low-cost imitations, but it works there. These opamps cannot generate infinite voltages so at some voltage their output voltage will be less than what you would ideally expect. Simulation is stopped when some current, voltage or internal variable reaches the limit of the available number range.

Solved: Bubba Oscillator as a sine wave inverter – Discussion Forums – National Instruments

You should be able to replicate similar results in your own simulator. Where did i go wrong? By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies. How to achieve a pure sinusoidal waveform from this bubba oscillator In control theory they call it PI controller.


This is the error message. This states that an oscillator oscillates when the loopgain is more than 1. If you zoom in on the left side you should also see the oscillation but at a much smaller amplitude. It does oscillate, you can see that it does on the right side of the plot.

Zoomed result Simulated for 10sec: This below is my circuit: So sorry to bug you, i am using MATLAB b, can you upload the file in previous version if thats not much trouble, if not, never mind. I have seen in practical circuits even a NTC resistor used here. A drastic improvement reduction of distortion is possible when we use two different supply rail voltage pairs and when the ouput is taken from the block with the larger supply voltage limiting effect in the block with smaller supply voltages.

op amp – Sine generator – Bubba Oscillator – Electrical Engineering Stack Exchange

A good analog sinewave oscillator has a specially designed contol circuit which checks the output amplitude and reduces the gain until output amplitude is the wanted. I have the design file I can upload. Here’s a circuit that should actually work, using a quad LT and a single power supply rail:.