Upon the date 05:06 PM 8/15/99 -0400, CLASSICCMP(a)trailing-edge.com said
something like:
Eric Smith wrote:
>William Donzelli <aw288(a)osfn.org> wrote:
>> The lights ("blinkenlights") on some early machines (and even a few not
>> so early machines) were tiny tubes, as well. A bit more simple than a
CRT...
Yes, but those weren't particularly "bizarre". They were just common
incandescent bulbs.
I've seen scientific and computer equipment from the 60's and 70's using
a variety of "tubes" as indicator devices, everything from simple neon
bulbs to decatron counters and storage CRT's.
One might argue that a neon bulb or a decatron isn't properly a "tube"
(they certainly aren't "valves" because they don't have a control grid
like a triode), but they are non-linear devices that are capable of
storing (and displaying) state information and performing simple logic
functions.
Question for the UKer's: is a tube rectifier (no control grid, just
an anode and a cathode) called a "valve"? Is a voltage regulator tube (like
the venerable OA2) called a "valve"?
Well, I'm not a 'UKer' but just a humble electronic communications
historian (like Bill Donzelli, who also knows this answer) who has a strong
interest in tube (valve) history. Back in 1908, Sir John Ambrose Fleming,
an English electrical engineer, patented the Thermionic Valve. It was based
on work he began in 1904 investigating the "Edison Effect", of which he and
Edison had discovered earlier in 1889 in USA, in order to make a rectifying
valve. This valve is a two element diode. On the other hand, Lee deForest
patented the Audion which is a three element valve, or "tube" in USA terms,
in 1906. Controversy had always surrounded DeForest, however he held fast
to his contention that he had developed the Audion *independantly* with
regard to Fleming's work begun earlier.
Yes, a two element vacuum thermionic diode can therefore be called a "valve".
Ya got a good question about the 0A2 and its kindred though Tim. I would
imagine by conventional wisdom it also would also be called a valve in the
UK. Tony? Know the usual expression for VR tubes? (VR valves?)
Regards, Chris
-- --
Christian Fandt, Electronic/Electrical Historian
Jamestown, NY USA cfandt(a)netsync.net
Member of Antique Wireless Association
URL:
http://www.antiquewireless.org/