Rescued retro scale

Rescued this thing in-box from a pile of scrap metal. Old enough that it was made specifically in West-Germany. Cheap enough that it's Not legal for trade. New enough that I can use it, considering I haven't previously bothered purchasing a bathroom scale for myself. As usual for appliances I come to own, this needed a little TLC before it worked properly

Opening it up is as simple as using pliers to unhook a couple of retaining springs keeping the top attached. Besides that it's the same cross-braced spring-tensioned mechanism as a traditional mechanical compact scale. You step on it, your weight pushes the metal bars down against a spring-loaded rod which drives a rack of teeth against a gear - usually driving the spinny display to scale your weight, but in this case driving a spinny encoder disk as input to an optical sensor! Magic! Repairing this unit was as simple as reattaching the return spring for the driving rod to it's home it fell off of. Probably happened when it was tossed :)

A little Hitachi microcontroller (ostensibly related to the lineup of 4470 character display controllers) ties all the magic together to give you a nice digital readout on a set of four 7-segment LED displays. Wonderfully retro.

2xAA powered! Single-toe activation for your domestic convenience!

You can "C" that it's ready to heft a load.

Excuse my fuzzy feets. So is that how much I weigh now? Only gained around 10lb since I last checked at the doctor's a decade ago - must be that trendy poverty diet routine I've stuck with. Or just a starvation background for fast metabolism :)