If you’ve ever fumbled through circuit simulation and ended up with a flatline instead of a sine wave, this video from [saisri] might just be the fix. In this walkthrough she demonstrates simulating a Colpitts oscillator using NI Multisim 14.3 – a deceptively simple analog circuit known for generating stable sine waves. Her video not only shows how to place and wire components, but it demonstrates why precision matters, even in virtual space.
You’ll notice the emphasis on wiring accuracy at multi-node junctions, something many tutorials skim over. [saisri] points out that a single misconnected node in Multisim can cause the circuit to output zilch. She guides viewers step-by-step, starting with component selection via the “Place > Components” dialog, through to running the simulation and interpreting the sine wave output on Channel A. The manual included at the end of the video is a neat bonus, bundling theory, waveform visuals, and circuit diagrams into one handy PDF.
If you’re into precision hacking, retro analogue joy, or just love watching a sine wave bloom onscreen, this is worth your time. You can watch the original video here.
Video seems lacking as an instructional video. It’s mostly a recording of her performing the exercise in Multisim, but she doesn’t actually walk you through it nor explain much as she does it.
She says nothing of the theory nor how the circuit works other than showing the manual at the end.
The part numbers of the capacitors placed in the sim don’t match up with the manual. It made the circuit theory in the manual confusing at first.
The video could do without the music. At least it wasn’t too annoying.
hmm. maybe consider a writing position at hackaday: “the sharp eye”. I would welcome such a refreshing view.
The only oscillator I have ever built in my life was an astable multi-vibrator. I would love to build a faster oscillator.
I should probably take some time out of my daily life and build all the basic circuits at least once.
you and me both. i even got ahold of a copy of a forest mims transistor book, sigh
Boy do I wish people would stop drawing Colpitts oscillators with the “center tapped” capacitor arrangement. It’s not a helpful depiction and makes it seem like something new when the reality is the feedback network is just a ladder filter. It’s an input series cap, a CLC pi network, and an output series cap. If you just think in terms of two-ports, it makes the whole concept generalize much better, and makes analysis easier, and puts the feedback network into a familiar format which is particularly useful for people learning the circuit for the first time. No idea why that particular drawing has stuck around so persistently.
When we were designing a simple 7 MHz direct conversion receiver, we used a Colpitts oscillator. We built it in LTSpice, really just to have a good printable document. I was astronished when the oscillator fired up in the simulator, and the whole receiver started to work IN THE SIMULATOR! We could put an RF signal at the input and watch an AF signal emerge at the output. It was really pretty neat. You can find the LTSpice file in this site: https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver. We recently asked people around the world to built the receiver. 56 of them have successfully did so: https://soldersmoke.blogspot.com/search/label/DC%20RX%20Hall%20of%20Fame Saisri’s Colpitts topology is a bit different from what we are used to, but her simulator shows that it works. I urge her to go into our Discord server and then build the receiver that used the same kind of oscillator that she has simulated. Bill
The connection is everything!