This is why 4-20 mA is a common signaling standard in industrial automation. 4 mA means zero and 20 mA means one. 0 mA means broken transmitter !
Interesting. That makes sense, but what’s the reason for using current instead of voltage as the variable?
Never trust a system that seems to be working
91–100 of 376 posts
Re: Never trust a system that seems to be working
#92Wow, Factorio is approaching Full Time Job levels of detail and work required to keep everything running. Incredible game that I will never play, I feel I’m back at my job!
Usually games or hobbies that feel like a job are much more fun because there's nothing wrong happening if you fail at it, or if one day you decide not to show up.
Re: Never trust a system that seems to be working
#93A bit of an off-topic: I only ever saw white traffic lights in the US and Canada (specifically, pedestrian traffic lights) and they confused me a lot at first - the rest of the world uses green. The icons displayed (hands) are confusing too: the rest of the world uses an icon of a man walking or standing.
Re: Never trust a system that seems to be working
#94Re: Never trust a system that seems to be working
#95This is why 4-20 mA is a common signaling standard in industrial automation. 4 mA means zero and 20 mA means one. 0 mA means broken transmitter !
Interesting. That makes sense, but what’s the reason for using current instead of voltage as the variable?
Re: Never trust a system that seems to be working
#96if dinosaurs and nobody anticipated dinosaurs > expected
Re: Never trust a system that seems to be working
#97Re: Never trust a system that seems to be working
#98[flagged]
Re: Never trust a system that seems to be working
#99Just want to note that the novel noted in the first post, The Moon Is A Harsh Mistress , is a great read. I think I read it after seeing it recommended in Mary Robinette Kowal's Lady Astronaut series, but it's a nice balance of technical and science fiction with politics, almost like a condensed version of KSR's Mars Trilogy. It's mostly (not entirely) devoid of the more typical Heinlein sexism/objectification.
Re: Never trust a system that seems to be working
#100This is why 4-20 mA is a common signaling standard in industrial automation. 4 mA means zero and 20 mA means one. 0 mA means broken transmitter !
It is also why white traffic lights no longer mean "go". White means "the red glass lens in front of the incandescent bulb shattered again". Related, from train signals: > The invention of the track circuit in 1872 by William Robinson permitted automatic block signals. Most simply, a low voltage battery current runs up one rail and down the other. As long as current flows from the battery through one rail to the rela…