A genuinely surprising bit of circuitry
Added 2022-06-19 03:31:13 +0000 UTCI don't think it's the circuitry that is the special thing about this. It's the use of what may be standard zinc-air cells as used in hearing aids, but the cells are used in a very strange way.
https://www.youtube.com/watch?v=Be9RU3PU1bw
Do zinc air cells liberate gas when passing current, while not getting their oxygen supply? Or are these specialist versions?
Some suitable googling has discovered a patent:-
https://patents.google.com/patent/US5242565A/en
To quote from that patent:-
"U.S. Pat. Nos. 4,105,830 to Kordesch and 4,189,526 to Cretzmeyer both describe "air depolarized" oxygen consuming "zinc air cells" but do not describe cells for the "evolution" of gases. Due to the teaching of the present invention it would be hindsight from the description of these cells to conclude that these cells contrary to their disclosures may be used as "hydrogen evolving cells" by simultaneously excluding oxygen from their cathodes and forcing electric currents to flow through the cells."
So it's possible that these are standard zinc air cells with the labels used to cover the air holes left on, and the resistor providing the required current flow so they liberate hydrogen to pressurise the grease plunger.
