I've always wanted a Shaper Origin, but the cost and subscription fee required for accessing some features always turned me off. I don't need it for anything other than fun hobby projects and couldn't justify it. Now I get double the fun: building a tool, and getting to use it! Nice work.
I spent a LOT of time on this website as a 90's kid. One of many that inspired me to get an EE degree. Projects like this always felt like some incredible magic, and came with an artistic aesthetic that I find inescapably captivating. We've instead got little bits of black epoxy everywhere these days and it's just not the same!
On your note about capacitor sizes — at my first EE job, my boss taught me about capacitance-voltage derating[0] for ceramic capacitors and it was quite the revelation. There is a significant inverse relationship between the two, which no one tells you about in college!
I'm now very careful to pick ceramic capacitors with enough headroom on their rated voltage as you lose a lot if you're close to the rated value. This curve is dependent on the different ceramic types as well (C0G, X7R, etc). Cheaper ceramics have a steeper rolloff.
For personal projects I am very careful to pick higher quality ceramics (X7R if I can) and use caps rated to 2-3x my operating voltage. Likely overkill, but I'm not optimizing for cost at volume.
It is not actually true that MLCC DC bias derating scales with voltage rating. The voltage rating itself actually has nothing to do with it. The correlation is with package size. (Package size and voltage rating are often loosely correlated (and were strongly correlated back in the day), which is where the misconception comes from.) The physical origin of the effect is electric field strength in the dielectric material; thicker dielectrics reduce the field strength, so you don't come as close to hitting the polarizability limit of the piezoelectric materials, at a given applied voltage. Voltage rating doesn't really show up in that analysis.
If you don't believe me, poke around a bit in SimSurfing or similar. You should also notice that most capacitors are actually binned by voltage rating these days: a 16V part and a 50V part might be identically specified, but one's curves just cut off at 16V. I don't know if that's strictly binning or just testing, but it's pretty clear they're the same parts under the hood.
> It is not actually true that MLCC DC bias derating scales with voltage rating. The voltage rating itself actually has nothing to do with it.
This statement used to be false (I used to design boards where I would bump the voltage rating to get better DC bias behavior), but it looks like the engineering behind these capacitors has changed "recently" (as in the last 10 years), and it is now mostly true.
Thank you (and the GP) for the correction! I'll admit this lesson came to me a decade ago and I am speaking to a rule of thumb I developed as a result. Time to update my knowledge banks.
The other thing worth mentioning is that there are multiple formulations, and they're not all equal. Just to pick on Murata, the last character of their part number is a reeling code (something so boring it's often omitted or wildcarded), and then the three characters before that represent the specific dielectric material in use. (Or something like that. It's a private use field and I'm reverse engineering it here.) For the examples above, that's "E01", "A01", or "A88". Each of those will behave differently in SimSurfing, but all parts with the same dielectric code will have the same DC bias behavior. (At least, they will if they have the same size and value, etc. When those change too, behavior still follows the usual trends.)
Parts with different codes can have vastly different behavior under DC bias. You'll find that one of them is the clear winner in most cases. Unfortunately, Murata knows this too, and that one is invariably more expensive in distribution.
But at least you can specify it!
Other vendors do this too, but it's easiest to see with Murata's setup and tools.
I live in Alameda and this place is such a local gem. The owners are really genuine people too. Great place to spend some time!
They also own a whole warehouse out at Alameda Point filled with machines. I know they have provided some form of access to the public in the past, but I'm not sure what that looks like today.
As a former Fit owner, I wish I had thought of this! The AC was really bad. We did a lot of road trips and it really struggled out on the long desert highway stretches.
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.
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.
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...
> 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?
That's really interesting. For me, I very much do NOT enjoy the taste of truffles in restaurant dishes because it's often so overbearing. I just don't find the flavor interesting, and it's very singular.
Perhaps I would enjoy the "real" experience more...
A lot of restaurants also just overdo how much they add in an attempt to make it seem like they put a lot of truffles into the dish and so there's a strong aroma from the dish. Whenever I use it, in something like my attempts at a mushroom truffle risotto, I will usually use a drop or two for a whole pan. Maybe a little more if I plan to cook the dish for a while after, such as if I am making a sauce that will simmer for a bit. Usually even a teaspoon is too much.
