Astoundingly, Thierry Excoffier’s Zero-Memory Widgets #IMGUI library from 02003 still exists and has been updated regularly including up to 02020!
#video by #Akio showing his Arduino-driven #switched-reluctance motor #electronics control board and working motor #hardware
#video on very simple single-coil #switched-reluctance motor #hardware. Not optimized; a low efficiency mild steel design, science-fair style. Requires manual start!
lecture #video from 02012 (? or 02019?) by JR Hendershot about #switched-reluctance motors (“reluctance synchronous motors”) mentioning ABB’s new #SynRM product line (17–350kW), mentioning higher torque density than induction motors (which use the exact same stator design) and lower cost than permanent-magnet electrical machines as key advantages. Cites a price spike in neodymium as a key reason for interest in the area, which makes me think it’s from 02012 rather than 02019, when it was uploaded to YouTube. It actually says that “reluctance synchronous” motors are different from “switched reluctance” motors. Shows little webs in the stamping to hold the flux carriers together in the transversely laminated anisotropy rotor. Shows ABB’s plot of efficiency over its product line, ranging from 88% at 1kW rated power up to 97.5% at 700kW, because of the missing ohmic losses in the rotor relative to an induction motor. Boglietti and Pastorelli’s paper from 02008 reports 17% higher torque for an SRM (RSM) version of an existing induction motor. Shows some asterisk-shaped switched-reluctance rotors (using higher frequencies) and contrasts with RSMs’ trippy rotor design (using the same inverters as for an induction motor). Also has some nice electronics schematics. “The key to the improvements in efficiency and power factor lies in the inductance ratio or the saliency ratio in the d [direct] & q [quadrature] axes.”
#video by #Murray-Smith about “game changer?” linear (or rather reciprocating) #switched-reluctance motors (or rather generators). Lots of talking-head filler, but at least a third actual information. But this isn’t actually a switched-reluctance design; it’s a permanent-magnet design! But with both the coil and the ring magnet fixed, coupled by a moving core. He said it took him two hours to make it from scratch, including the wood base I guess, which is sort of a game changer. He gets 600mV open-circuit voltage spinning it by hand and 40mA short-circuit current, so ≤24mW, which makes it less of a game changer since he’s exerting several watts of power to spin the crank. (He claims “It’s generating quite a lot of energy from something so trivial!” but according to his measurements it isn’t.)
#video about air-core axial-flux DIY motor-generators
#video about "SynRM" #switched-reluctance motors made out of sheets with slots punched out to follow field lines. Low-quality AI voiceover from #Lesics. #hardware
#video taking apart some #Tesla motors and discussing how their #manufacturing is done. The motors have a lot of electromagnetic poles, like hundreds of poles, on the three-phase stator, although they do gear the motor down to the wheel. There are cooling channels through the stator. The rotors seem to be permanent-magnet type with laminates (electrical steel?) and carbon fiber wound around them presumably to keep them from coming apart. The laminates give you almost no flux outside the rotor except at 12 spots around the circumference where there’s a gap comparable to the size of the poles on the stator. The magnets are actually quite small compared to the whole rotor.
"Janet" is an embedded Clojure-inspired #Lisp programming language written in C, adding about a megabyte to your binary, with PEG support, a REPL, an interactive debugger, threads, networking, an event loop, macros, TCO, prototype-based OO, and a wasm playground in this web page.