From: "Poul-Henning Kamp" <[EMAIL PROTECTED]> Subject: Re: [time-nuts] LED reliability Date: Wed, 30 Apr 2008 17:12:56 +0000 Message-ID: <[EMAIL PROTECTED]>
> In message <[EMAIL PROTECTED]>, Hal Murr > ay writes: > > >> LEDs been viable since at least the early 70's? Talk about planned > >> obsolescence... > > > >How reliable were the early LEDs? When did they start to get used in high > >reliability applications? > > Many of them are still happily emitting their faint red or green light. If you do not drive your LEDs too hard, they will surely survive longer. > >The best reliability story I heard (many years ago) was about installing > >another trans-Atlantic telephone cable. They used tubes long after > >transistors were out. They knew how long the tubes would last. They didn't > >have much data on transistors yet. > > Actually, that's not entirely correct: They had reliability info > on transistors and they sucked. Konrad Zuse stayed with relays for quite some time, since it took time for the much faster tubes to become reliable enought. However, he used his relays wisely, since they always changed state with the contactors carrying no current. The commutator driven by a synchronous motor took that heat. One place to service. Cheers, Magnus _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
