31 Aug
2006
31 Aug
'06
4:14 p.m.
On Thursday 31 August 2006 02:25 pm, Jim Beacon wrote:
From: "Ethan Dicks" <ethan.dicks at
gmail.com>
Not necessary to use those, you can do pretty much the same sort of thing
with any relaxation oscillator. My shot at doing it in this gear would be to
use neon bulbs. I have an early 1970s "Chro-Bar" signal generator that uses
this principle for frequency dividers, only they use unijunction
transistors, three stages of them, and three trimpots in the back to tweak
because it's damn temperature sensitive.
Oh yeah, and it'd run off a "VS-133" _Mercury_ cell if I could find one.
:-)
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
On 8/31/06, woodelf <bfranchuk at
jetnet.ab.ca> wrote:
Thyratron divider circuits.
http://www.g1jbg.co.uk/thyratro.htm
Divide by any integer, using around 6 components (the practical division
limit is around 6, but I've made them work as a divide by ten). The ads list a 12au7 for about 65 cents in 1955.
In 2006 a generic
12au7 is about $8.00. I suspect a better deal now than 50 years ago.
Hmm... if I leave off seconds and just go with minutes/hours, I think
I have enough. Even with modern wages, a bag full of tubes costs
enough to make me want to simplify the design.
The real trick, now, I guess, is how to take 60Hz mains and clock it
down to 1/60Hz with 1955 technology.
-ethan