On 2/10/19 10:16 AM, Richard (Rick) Karlquist wrote:
On 2/10/2019 4:35 AM, Rice, Hugh (IPH Writing Systems) wrote:
Somewhere over the years I picked up this line: “A good engineer is
a lazy engineer. They are always looking for the easiest way to do
things.” The designer of the 5061A battery charger was definitely
not a lazy engineer.
My contention is that ALL engineers are lazy to a certain extent -
rather than everyone wading across the river and getting wet, you build
a bridge - rather than dig in the soil of a field with a pointed stick,
you get an animal to drag it across the field for you - etc.
The idea of "do something with less work" or "do something that cannot
be done" is sort of fundamental to engineering.
2. The giant unobtainable mica capacitor has Len's fingerprints
all over it. On the 5071, Len wanted to use a tantalum capacitor
for the power supply filter. Imagine what that cap would now cost
in these days of "conflict minerals". The project team mutinied and Len
backed down. It was all moot anyway after we decided to use Vicor
modules. That seemed very avante garde at the time, but now seems
sensible. BTW, I heard the those giant WWII military mica capacitors
were made from large contiguous chunks of mica. A some point after
the war, the mica mines were played out, similar to the quartz mines,
and only small pieces of mica were available. The capacitor vendors
made "reconstituted" mica out of crumbs. The crystal vendors didn't
have that option so they had to invent synthetic quartz.
Yes, those brown roughly 1" square caps used intact sheets of mica as
dielectric. You can easily split the mineral into uniform, thin,
transparent sheets.
The reconstituted caps are still around - used in high power RF circuits
(mica has really low loss, but high epsilon) and in Tesla coils (a sort
of special case high power RF). Most of them are surplus Russian/Soviet.
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