Heathkit EC-1

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Fri May 2 18:54:01 2003

> > I don't think _my_ auto (1968 Beetle) is an example of that. :-)
>
>
> Well, now - not so fast! While your Bug may not have power steering, if
> it's got an automatic transmission - then I submit that:

Very few Beetles (at least in Europe) had automatic transmission....

>
> The automatic transmission as found in a good portion of the cars,
> trucks, and busses on the roads today, is a marvelous and complex analogue
> computer - solving for the match of the mechanical impedances of the

I've never worked on an automatic transmission, but I have read the shop
manual for the Borg-Warner model 35 (which was the standard unit fitted
on UK automatic cars in the 1970s).

The control valve block is a work of art. Slide valves operate on
differences in pressure between hydraulic lines (or between a single line
and a spring). The pressure in some lines increases as the engine runs
faster (thus rotating the pump faster), and so on. I am still amazed it
works!

And of course the torque converter is a rather neat little impedence
matching analogue computer...

-tony
Received on Fri May 02 2003 - 18:54:01 BST