3 ms·

A Symbolic Analysis of Relay and Switching Circuits (1937) [pdf]

45 points by jcgr 8y ago

olodus 8y ago
Awesome. Was looking for this after reading that other awesome blog post about Boole. Once again HN to the rescue, saving me from a Google search.
- hypeibole 8y ago
  Do you have a link to the post about Boole?
  - tacon 8y ago
    This appears to be the referenced post: https://news.ycombinator.com/item?id=19091398 https://news.ycombinator.com/item?id=19091398
codewritinfool 8y ago
This is great
jesuslop 8y ago
Very nice. The current rendering of this would be to formulate with relay/resistors the 2 gate NOR as universal gate giving arbirary boolean functions and the 2 NOR crossed feedback setup as RS-flip/flop or elementary memory bit. All this can be done with hobyist materials.
cabalamat 8y ago
Is this where ladder logic comes from?
- qntty 8y ago
  I believe this paper is the first time that anyone thought to analyze electronics using logic at all. Nobody thought that techniques used to analyze philosophical and mathematical arguments could be used to understand electronic signals before Shannon.
  - deleted 8y ago
    [deleted]
kens 8y ago
Interestingly, up until the early 1950s it was still controversial if Boolean algebra was useful for computer design. The argument was that buildable circuits were simple enough to analyze without Boolean algebra so it was pointless mathematical formalism.
jhallenworld 8y ago
Relay logic was certainly used prior to this. For example elevator call logic goes back to the 20s: http://elevation.wikia.com/wiki/Elevator_control_system http://elevation.wikia.com/wiki/Elevator_control_system Clearly the engineers involved had some way to think about it, but I suspect were not scholarly enough to write a paper about it. (not that I've researched this.. perhaps there were earlier papers). Edit: Well here is a patent: https://patentimages.storage.googleapis.com/82/ae/57/d431cf0f65e923/US1904647.pdf https://patentimages.storage.googleapis.com/82/ae/57/d431cf0... David Lindquist was Otis's lead engineer..

45 points by jcgr 8y ago

Awesome. Was looking for this after reading that other awesome blog post about Boole. Once again HN to the rescue, saving me from a Google search.

hypeibole 8y ago
Do you have a link to the post about Boole?
- tacon 8y ago
  This appears to be the referenced post: https://news.ycombinator.com/item?id=19091398 https://news.ycombinator.com/item?id=19091398

codewritinfool 8y ago

This is great

jesuslop 8y ago

Very nice. The current rendering of this would be to formulate with relay/resistors the 2 gate NOR as universal gate giving arbirary boolean functions and the 2 NOR crossed feedback setup as RS-flip/flop or elementary memory bit. All this can be done with hobyist materials.

cabalamat 8y ago

Is this where ladder logic comes from?

qntty 8y ago
I believe this paper is the first time that anyone thought to analyze electronics using logic at all. Nobody thought that techniques used to analyze philosophical and mathematical arguments could be used to understand electronic signals before Shannon.
- deleted 8y ago
  [deleted]

kens 8y ago

Interestingly, up until the early 1950s it was still controversial if Boolean algebra was useful for computer design. The argument was that buildable circuits were simple enough to analyze without Boolean algebra so it was pointless mathematical formalism.

jhallenworld 8y ago

Relay logic was certainly used prior to this. For example elevator call logic goes back to the 20s: http://elevation.wikia.com/wiki/Elevator_control_system http://elevation.wikia.com/wiki/Elevator_control_system Clearly the engineers involved had some way to think about it, but I suspect were not scholarly enough to write a paper about it. (not that I've researched this.. perhaps there were earlier papers). Edit: Well here is a patent: https://patentimages.storage.googleapis.com/82/ae/57/d431cf0f65e923/US1904647.pdf https://patentimages.storage.googleapis.com/82/ae/57/d431cf0... David Lindquist was Otis's lead engineer..