Analog vs Digital devices, was Magnetics

From: ajp166 <ajp166_at_bellatlantic.net>
Date: Tue Nov 7 22:06:48 2000

From: John Lawson <jpl15_at_panix.com>


>meter, in real time. This may sound cumbersome today, but consider in
>that in the mid fifties, digital computers were very, very expensive,
>fairly rare, and every single problem required much analysis and coding,


It would be 1979 before there was DSP fast enough to do a FIR filter
digially for audio frequencies, Analog had been doing that for 30+ years.

> PS: Anyone *really* interested in getting into analog computing might
do
>well to consider scarfing up a Heathkit EC-1 when possible.. they are
>simple, small and portable, and have easily replaceable tubes, and
having
>(IIRC) 9 opamps, one can get quite elaborate with them.


One could duplicate it using modern analog opamps and still solve the
same problems. The best one I remember solved a bouncing ball, for
varying gravity and rebound rates and "drew it" on an O'scope face.
It was a Popular Electronics (maybe RE) design. Still very buildable.

It's often forgotten that there were different op-amp designs that
allowed
things like four quadrant multiplcation, LOG and ANTILOG amps, CLIPPING,
SUM, DIFFERNCE, ABSOLUTE VALUE when combined allow solutions
of great speed with good accuracy.


Allison
Received on Tue Nov 07 2000 - 22:06:48 GMT