[rescue] argh, what did I do? (Onyx)

Jochen Kunz jkunz at unixag-kl.fh-kl.de
Wed Jan 15 13:19:47 CST 2003

On 2003.01.15 08:23 Bjorn Ramqvist wrote:

> The only exception I can think of is perhaps (BIG) old VAXen.
Hmm. Isn't there a VAX that uses three phase motors for the blowers?
Thinking of that big CDC Cyber supercomputer I saw at the VCFe that is
driven by a motor-generator as it needs 400 Hz AC. The motor-generator
can convert 80 kW...

> (However, someone did rewire a VAX6k to singlephase 230V I think)
Yes, that is possible. The VAX 6k has a 320 V DC power rail that is feed
from a three phase rectifier. This makes a rather smooth DC voltage from
AC even without smothing capacitors. The actual PSUs are feed from this
DC rail. It is easy to rewire the machine to work with 230 V single
phase. You loose the nice three phase rectifier factor, but it still
works. AFAIK you have to do a litle bit to fool the AC-OK detection.


Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/

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