8 May
2006
8 May
'06
12:25 p.m.
Tim Shoppa wrote:
The true value of analog computers comes in when you
stop dealing
with "static" math and start dealing with "dynamic" math.
Actually analogue computers are in daily active use, and were made right
up until at least the early '90s!
If you crack open the injection "computer" for a car fitted with Bosch
LE-Jetronic or its derivatives, all you'll find inside is opamps and
monostables. These do a sterling job of tweaking the injector pulse
length from a nominal value of 2ms, depending on airflow and RPM.
As an aside, most "limp-home" modes on injection ECUs that *do* use a
microprocessor simply squirt fuel for around 2ms every time the ignition
fires. It finds its way into the cylinder and burns the next time around...
Gordon.