“You bag 'em, we tag 'em”

IIRC, the first model ate mosfets for breakfast because the photo resistor is way too slow going from illuminated to dark. That leaves the mosfet in a fairly high resistance state for an extended amount of time during which it dissipates a lot of power. You should add some kind of Schmitt trigger inverter that buffers the resistive divider and gives you a clean narrow edge to drive the mosfet gate. A 74HC14 together with a 7805 voltage regulator should give you enough output voltage to drive the mosfet. These chips cost less than a single replacement mosfet and you can drive 6 coils with them.

Sets of measure zero are unfair. But you’re right, the second line in the image is basically an eigenvector equation for Int and eigenvalue 1, where the whole point is that there is a subspace that is mapped to zero by the operator.

I’m still curious if one could make this work. This looks similar to problems encountered in perturbation theory, when you look for eigenvectors of an operator related to one where you have the spectrum.

What is meant here, I believe, is (1 - Int)^-1. Writing 1/(1 - Int) is an abuse of notation, especially when the numerator isn’t just 1 but another operator, which loses the distinction between a left and a right inverse. But for a bounded linear operator on a normed vector space, and I think Int over an appropriately chosen space of functions qualifies, (1 - Int)^-1 equals the Neumann series \sum_k=0^∞ Int^k, exactly as in the derivation.

Int is injective: Take Int f = Int g, apply the derivative, and the fundamental theorem gives you f = g. I think you can make it bijective by working with equivalence classes of functions that differ only by a constant.

It’s reverse: you get a board that has a floppy interface on one side and a USB socket on the other. You plug in a USB drive and the board uses a file on the drive as the floppy disk, pretending to be a floppy Drive connected to the interface. It’s a little less convenient because you have to deal with disk images but it works without moving parts.

It’s probably not a good idea for actual use, but if you’d like to experiment: looks like the 3-pin devices U4 and U5 on the upper right provide feedback through the optocouplers next to the class Y cap north of the transformer. I bet those are LM431 voltage references (or similar). The passives around them provide filtering, but two of the resistors should form a resistor divider for the Ref pin (lower right pin if the single pin is on top). That divider sets the voltage.

Getting the order right is not an exact science. It’s more of an UART.

Isn’t that the same for Reddit or Lemmy? The content creators and mods don’t see a penny either. Operationally, a social network probably requires a lot more compute power and somewhat more bandwidth compared to a site that serves mostly static content. But I don’t see why small donations shouldn’t cover that. The cost per user seems moderate, otherwise few people could afford to run an instance with 1000s of users without charging them.

I hope they will. My guess is that a nonprofit like Signal will pull out. They have nothing to gain and a reputation to lose. The others will probably comply by implementing some form of client-side scanning.

If they force messengers to implement backdoors into the protocol, I doubt they will limit it to UK users. Also, conversations with UK users won’t be private anymore even if the other party is from another country.

Client-side scanning might not be enforced for other accounts but when the infrastructure is there other governments will want to use it, too.