Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!columbia!rutgers!sri-spam!ames!ptsfa!ihnp4!inuxc!inuxh!rmrin From: rmrin@inuxh.UUCP (D Rickert) Newsgroups: sci.electronics,talk.bizarre Subject: Re: "Magic Eye" tubes Message-ID: <591@inuxh.UUCP> Date: Wed, 22-Jul-87 17:32:23 EDT Article-I.D.: inuxh.591 Posted: Wed Jul 22 17:32:23 1987 Date-Received: Sat, 25-Jul-87 01:47:11 EDT References: <1495@frog.UUCP> <35ffa63b.b8ab@apollo.uucp> <6@spar.SPAR.SLB.COM> <1841@kitty.UUCP> <10018@dual.UUCP> Organization: AT&T Consumer Products, Indianapolis Lines: 31 Xref: mnetor sci.electronics:1039 talk.bizarre:2604 > < The "Decatron" tube, which consisted of a round tube with ten > < anodes, equally spaced about a circle. It was nothing more than > < a multiple neon lamp, since it displayed no digits, but each anode > < was labeled on the panel. Example: a Baird-Atomic nuclear scaler > < that I once used. > > Actually the Decatron was quite ingenious. It not only indicated, but > also did the counting. A major plus in pre-IC days. They were not > particularly fast, I seem to recall a figure of a few hundred KHz. > They consumed little power, just a few mA at hundreds of volts. > > There was a whole range of rather odd neon type devices available at one > time, that could be used for counting and other logic. These typically > had a trigger electrode that "fired" the device and started conduction > between the main electrodes. Reducing the current through the main path > would turn the device off again. There must be some people on the net > who actually designed with these things. > > Paul Wilcox-Baker > Tel 415 549 3854 > Telex ITT 470844 > Dual Systems Corp > 2530 San Pablo Ave > Berkeley CA 94702 Yup, many years ago I did a lab project in which we used a Decatron for motor speed control! The idea was for the circuit to keep the same little dot continuously lit if the motor speed stayed constant at the set point. A wonderful mix of analog, digital, and power technology. I think we may have even had a mag amp somewhere in the circuit (you know, solid state Neanderthal style).