In my upper-division analog electronics class (the hard one), our lab project throughout the quarter was to build an analog computer that simulated the physics of a bouncing ball. Physical variables of the system were adjustable (gravity constant, coefficient of restitution, etc), and the ball was "released" by pressing a button. The output was viewed on an oscilloscope.
One of the hardest 10 weeks of my life, but also one of the most rewarding. Our team was one of the few that actually got it working in the end. I had to custom-make a gigantic breadboard to hold the entire circuit.
Today I still work in hardware, but mostly with digital circuits. While my analog knowledge has decayed over the last decade, that project and it's success gives me great confidence any time I have to deal with the domain.
If you want to take a look, here's a pretty similar project: https://www.analogmuseum.org/english/examples/bouncing_ball_...
Hey, I made something like this a couple months ago! (Except it's more like "Tennis for Two", so you also hit the ball in the X direction, and there's another button to hit it back in the other. I didn't have any space or potentiometers left to set the gravity, but it wouldn't be difficult.)
I also learned heaps! (Including after a few weeks when the circuit stopped working properly because one of the relays started to work just a little slower than another one, heh.) If anyone's interested, https://blog.qiqitori.com/2024/08/implementing-tennis-for-tw...
My version of this was a 10-week discrete RF circuits course in graduate school. We had to build a fully functional GHz transceiver out of small FR4 PCBs (< quarter wavelength) and throw-away leaded BJT transistors. Neither were suitable for GHz circuits, so the course was hard by design. I learned so much and developed an intuition for electromagnetics that I still carry 20 years later.
> Today I still work in hardware, but mostly with digital circuits. While my analog knowledge has decayed over the last decade, that project and it's success gives me great confidence any time I have to deal with the domain.
Do you think about the analog qualities of your traces when laying things out? If so then the course was well taken.
In my observations I've found that too many digital engineers assume a differential pair will save them without actually fixing the impedance and parasitic issues. Particularly as the timings of things become so much more precise analog is so important. People forget that a digital circuit is just an analog one under the covers.
Did the mathematical model being used have a differentiable heigh function? I’m imagining it would be the simplest if it didn’t but that could cause problems in the electronics.
Also what components did you have access to, just op amps?
Just op-amps and FETs for the active components. The design from my memory was:
- To get position, 2 integrators were applied to an adjustable voltage representing gravity.
- The FETs were used to set initial states of the integrators.
- A comparator used to detect the table (y=0), flip the velocity and apply a scaling factor for restitution
The math was actually quite simple given its just the standard velocity equations — the challenge was in handling state changes in the electronics.
I looked around a little more and this video is a very close replica of what we built: https://www.youtube.com/watch?v=qt6RVrmvh-o
There’s no better introduction to signals and systems than a modular synthesizer IMO - the combination of tactility and audibility for multi-sensory learning is so great at building intuition - and more importantly, excitement! - for signal processing.
This looks like a cool project in the same spirit!
I agree. I highly recommend [0] Moritz Klein's channel. amazing explanations and learning effect.
I was going to say the same - does this follow 1V/octave standard, and is this available in Eurorack format? ;-)
Cool, I was thinking about the other way around, using an analog computer to build synthesizers.
This fella is using it as part of his music making https://www.instagram.com/stephano.music/
As a different sort of analog computer, I have long been wondering about a “compiler” for fluidic logic that can output devices you could 3D print which would then operate on pneumatic or hydraulic signals. Probably entirely useless, but wouldn’t be affected by an EMP!
That idea was shamelessly inspired by the soft fluidic robot some years back.
> wouldn’t be affected by an EMP!
Even better, it would only be affected by relatively rare phenomena, such as vibration, temperature change, orientation and rotation.
> that can output devices you could 3D print
Make it analog all the way by hooking it up directly to a lathe or milling machine.
Something like that is inside some automatic transmissions.
Sperry UNIVAC once built a 4-bit fluidic ALU as a demo, but it was useless.
A built-in scope display would be nice. Like this $10 module.[1] Then you could use this standalone. They charge EUR 499 for the thing, after all.
The way you usually run an analog computer is to put it into fast repeat mode (which they call REPF), where it cycles between initial condition mode and run mode. Outputs go to a scope. Then you can twiddle the knobs and see the output respond immediately.
The other modes are used mostly during setup and debug.
Hours of fun. Ages 14 and up.
[1] https://www.alibaba.com/product-detail/YIXINTAI-DSO138-Digit...
Prior discussion:
It's a cute toy and a fun educational tool, but "computing for the future" seems like a bit of an overstatement.
I think they're saying analog computers could be the future of computing.
Veritasium explains it really well in general here (and demos the device) https://www.youtube.com/watch?v=GVsUOuSjvcg
I've ordered one last holidays and haven't had the time to use it yet. Unfortunately it doesn't fit in the famous dev board drawer.
is it possible to buy this thing in the USA (no vat)