Subject: Re: Digital divide by ten, 1949 style
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Date: Sun, 15 Sep 2002 18:24:01 GMT
NNTP-Posting-Date: Sun, 15 Sep 2002 14:24:01 EDT
Organization: Cox Communications
"Tim Shoppa" wrote in message
> In a recent thread on sci.electronics.design, we explored some approaches
> to divide-by-ten without using IC's. (Go to http://groups.google.com/ and
> search for "Decade counter without IC's"). Here's an approach I found
> in Vol. 19 of the Radiation Laboratory Series, _Waveforms_:
> They do it with just ten tubes, and the output is BCD on 4 neon bulbs.
> Comments on similar counters would lead me to believe that the design is
> good to a few MHz.
Potter, "A Four Tube Counter Decade," Electronics, June, 1944, p. 110.
Reprinted in Markus and Zeluff, "Handbook of Industrial Electronic
Circuits," McGraw Hill, New York, 1948.
They only use 4 tubes, but the tubes they leave out look like the neon bulb
drivers used in the circuit you point to. The latch circuits are basically
the same, using dual-triodes.
The previous circuit in Markus and Zeluff is a divide by 4 whose output
could be used as the input to a counter. It's a similar circuit, using two
triodes for each latch, and was said to run at 1.25kHz. Williams, "High
Speed Thyratron Automatic Counting," Proc. Roy. Soc., May, 1932, abstracted
in Electronics, July, 1932, p. 232.
At least one ring oscillator (called a ring counter) appears in Markus and
Zeluff, from a 1946 Electronics article about a different circuit. What's
the earliest ring oscillator anyone has heard of?
-- Mike --