Same! Plenty of systems still use relays today such as the ... MTA Subway [0], ha. And elevators [1]. And definitely pinball machines [2]. And old telephony systems [3] although I doubt those kinds are still in service?<p>As far as I understand, some/many? industrial PLC systems are programmed using "ladder logic" which encodes logic as a (virtual) circuit of relays.<p>They were here before Shannon (used in telephone, rail signaling, etc.), got infused with math and a new meaning (formalized computing!) in his incredible master's thesis, and are still with us today.<p>My personal faves on the topic: Tim Hunkin's beautiful machines [4] which you can see in London, and his series on components - including relays of course! [5].<p>Cheers :-)<p>[0] <a href="https://en.wikipedia.org/wiki/Signaling_of_the_New_York_City_Subway#Block_signaling" rel="nofollow">https://en.wikipedia.org/wiki/Signaling_of_the_New_York_City...</a><p>[1] <a href="https://www.youtube.com/watch?v=wS3CkGzbsOo" rel="nofollow">https://www.youtube.com/watch?v=wS3CkGzbsOo</a><p>[2] <a href="https://www.youtube.com/watch?v=uj8raZYHncQ" rel="nofollow">https://www.youtube.com/watch?v=uj8raZYHncQ</a><p>[3] <a href="https://www.youtube.com/watch?v=xZePwin92cI" rel="nofollow">https://www.youtube.com/watch?v=xZePwin92cI</a><p>[4] <a href="https://www.youtube.com/watch?v=dBbXkOY4oao" rel="nofollow">https://www.youtube.com/watch?v=dBbXkOY4oao</a><p>[5] <a href="https://www.youtube.com/watch?v=fdj_g_1tj4c" rel="nofollow">https://www.youtube.com/watch?v=fdj_g_1tj4c</a>