Tony Duell wrote:
Generally
still OT, but on-topic regarding the maintainability of
modern devices, did anyone perchance read the "A New Spin on White
Goods" article in the December 15, Electronic Design?
My clothes washer and dryer are going on 17 years and work just fine.
I see no reason that I won'd get 20-25 years of service out of them.
But reading about technology in the pipeline makes me wish they'd
last forever.
I made comments like this a couple of weeks ago and was roasted alive for
them. Oh well....
Motors controlled by DSPs with 10 A/D converters
on chip, GUI
displays, talk about inventorying the stuff in your refrigerator
Ouch. Those old cam timers were repairiable. I've never had a cam fail,
the motors are pretty much interchangeable, and switch contacts can be
repaired (either using bits of old relay contacts, or by using the burnt,
but still jsut about working contacts in the time to switch a relay). But
I wouldn't fancy having to repair a board with a single ASIC on it that
contains a programmed microcontroller amongst other stuff.
Te presense of an 'old fashioned' rotating program knob doesn't imply a
fully electromecahanical timer. I've seen at least one washing machine
where there was a motor-drivven cam stack, but the timer motor (and some
otehr bits of the machien) were controller by an ASIC (with feedback
contacts on the cam stack to tell said ASIC where it had got to).
And of course some eyars ago, 'electronic control' was reserved for the
high-end models, you could get a mechancial timer by buying a cheap
machine. Now, of coruse, microcontrolers are a lot cheaper than motors
and cams, so all machines have the electronic control
(the same sort of thing applies to car engines. 20 years ago, a 16 valve
(4 cylinder) twin overhard camshaft, fuel ingjected engine with an
ignition coil for each spark plug (no distributor) would have been
reserved for a high-performance car. My father's new car, a base model
Skoda, has such an engine)
As I said earlier, though, that's probably for emissions reasons more
than price or performance. A modern 2.2 litre 16-valve engine may
produce slightly more power at rather higher revs than the 8-valve
carburettor-fed PSA Douvrin in my CX, but at the expense of losing quite
a lot of torque. I still hate working on carburettors though. Fuel
injection is way simpler.
BTW, when I looked at replacement ovens over the
last few days, I
found that just about all of the new ones are loaded with features
that I'll never use, such as "Sabbath Mode" (no kidding).
What the heck is Sabbath Mode?
I'm guessing it's something where you can put food in the night before,
and it will cook and shut itself off the next day. Certain faiths
require that you do no work on the Sabbath, and that includes cooking.
I went to school with people whose mothers would prepare the Sunday meal
late on Saturday night, to be eaten cold after coming home from church.
Some of them wouldn't even use electric light on a Sunday, so in the
winter they'd be sitting in the dark from about 4pm onwards. And people
think Muslims are bad for crazy religious fundamentalism...
Gordon.