OK, not Z related, but Chinese crap related: Night before last, our security alarm kept going off in the middle of the night, until I finally had the sense not to re-arm it. The offending zone was a contact sensor on the garage door. The next day I went to diagnose it. It turns out that the reed switch had a resistance of 29 ohms when closed, and the circuitry to which it was wired couldn't decide whether that was open or closed.
A reed switch...
A Chinese reed switch...
I mean, how do you screw up making a reed switch? It's one of the simplest and most robust designs of switch there is.
Sadly, all reed switches seem to be made in China, so far as I'm aware. I replaced the offending Chinese reed switch with another Chinese reed switch whose contact resistance is of a fraction of an ohm. We can now set the alarm again without the system going off spontaneously at 4:00 AM. It was a $2 part that wasted one night's sleep and an hour of two of my time.
I wish we could start making stuff here in the US and Canada again. I'd buy it.
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