2 Jun
1998
2 Jun
'98
2:11 a.m.
It's generally 400 (plus or minus 50) hz for
aircraft and associated
equipment (missiles for instance). Our test equipment racks for Air Launched
Cruise Missiles had a HP 1000 computer tied to an IEEE 488 interface and all
of that ran from a motor-generator that took 3 phase 220 volt @ 60hz to
power an electric motor that turned a generator similar to an aircraft's
engine driven generator.
Quite a bit of military equipment actually is rated to 2400 Hz. The reason
for this is that some of the pre-1940 aircraft (namely U.S.Navy) used 800
Hz power. There were also probably a few applications that went a bit
further in line frequency, but I am not aware of them. Anyway, an amazing
amount of this pre-war "junk" stayed in service into the 1970s.
If anyone wants a BIG 400Hz convertor from an IBM 3090 installation, there
is one in a junkyard in Illinois. It looks to be in the 1500 pound
category.
Locomotives [...] also use 400hz equipment.
Maybe the new ones, but the old ones used 25 Hz.
William Donzelli
william(a)ans.net