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#relaylogic#elevatorcontroller

(1/4) PROBABLY THE BEST 'elevator relay logic vid' in the world! - Part 1 of 4

mrmattandmrchay

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YouTube
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Intermediate. Assumes working knowledge.

61K views14 years ago1 recommendation

HardwareHistory and cultureRetro computingElectronicsHistory of computing

An exploration of an original 1970s elevator motor room operating entirely on electromechanical relay logic.

VIDEOS: This is Part 1 - "into the motor room or not!?" - Exploring an original 'Express Lifts' lift motor room Part 2 - "how it works" (my favourite part!!) Part 3 - "EXPERIMENTS" - different lift, same design, more relays, MORE EXPERIMENTS! Part 4 - "EXPERIMENTS2" - more experiments and some motor room footage (and a fan!) ABOUT THE VIDEOS: Here is a month's worth of editing - not all at once though! All this was filmed with one camera over two seperate visits and painstakingly sychronised into split screen segments to give you an excellent view of everything that is happening in this original 'Express Lifts' installation. As per the introduction in Part 1 - this is pure relay logic from the 1970s where microprocessors in lifts did not exist. And even better - this 'Express Lifts' lift is almost completely original - only the photoelectric door edge sensor has been added. Love those floor display lamps inside the lift! This lift even has the mechanical floor selector that I've been wanting to film for years. A facinating piece of equipment for determining the lift position within the shaft. This has been clunking away since the 1970s - this kit was built to last! Enjoy the videos. I'm a perfectionist and have edited these to make them as interesting as possible, and of course as informative as possible as well! Check out the relay sequences in Part 2 in slow motion - all labeled and the text illuminates with the operation of each relay...do you know how long this took to do!!!?? :D A LITTLE INFO ABOUT RELAYS: A relay is a switch activated by an electromagnet. A relay can contain one or many switches which all move together. Using this, and other mechanical devices, this is how lift systems worked before microprocessors were introduced in the 1980s. It's called 'relay logic' because the switches are used to make decisions, such as which lift should go to which call (for larger building with more than one lift). Whereas a computer program can be programmed to make this decision quite easily, to connect wires to relays and switches to make the same thing happen can be complex. But if you know what you're doing, it works! I LOVE RELAYS by the way, and I've been working with them since I was about 12 years old! :) Hope you enjoy the videos! Matt

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What people say. Recommended to illustrate how complex control systems operated using physical relays before microprocessors.

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u/COMPUTER1313in r/programming • Recommends

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…all of them are gone. At my workplace, we had a 1950's or 1960's industrial control system with no transistors in it. All logic calculations and input/output operations were done with electromagnetic relays and mechanical cam timers. An elevator control system that used those hardware components, just to get an idea of how that machine operated: link to this video No one really knew how that machine worked anymore, and some of the electrical diagrams were missing or degraded. That beast ran until it had an electrical fire, which some of the remaining diagrams also got carbonized in the process. An entire production line was shut down from that ancient single point of failure burning down. The hila…
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