Article View: sci.space
Article #1952Re: space news from Oct 2 AW&ST
From: Henry Spencer
Date: Tue, 28 Nov 1989 06:09
Date: Tue, 28 Nov 1989 06:09
24 lines
1659 bytes
1659 bytes
In article <4300@helios.ee.lbl.gov> mikec@ux1.lbl.gov (Mike Chin) writes: >Why is 20 kHz bad? I vaguely remember an article in Powertecnics describing >this system, but I wasn't aware of any controversy. The 20kHz power system was bad because it was new technology for the sake of new technology, instead of new technology for the sake of a working space station. It did promise some modest improvements in weight. In return, it demanded that all power equipment be developed from scratch, specially for the space station. Not even the light bulbs would be standard. The obvious alternative -- use 400Hz aircraft systems -- would have been slightly heavier but vastly cheaper, because much of the hardware could be had off the shelf and all the design issues were fully understood. >I was involved in a Explorer sat project where all voltages were derived >from a 28V bus; designing the DC-DC converters was a major effort (luckily >not done by me). I agree that the switch to DC sounds dumb, although I haven't seen a detailed technical explanation of the tradeoffs. As I said, I suspect it's a face-saving maneuver for someone. -- That's not a joke, that's | Henry Spencer at U of Toronto Zoology NASA. -Nick Szabo | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
Technical Details
Message-ID:
<1989Nov28.060957.12226@utzoo.uucp>Path:
arc1-ca.pugleaf.net!utzoo!henryReferences:
<1989Nov26.223357.27453@utzoo.uucp> <4300@helios.ee.lbl.gov>Show Full Headers
Complete Article Headers
Newsgroups: sci.space,sci.space.shuttle Path: arc1-ca.pugleaf.net!utzoo!henry From: henry@utzoo.uucp (Henry Spencer) Subject: Re: space news from Oct 2 AW&ST Message-ID: <1989Nov28.060957.12226@utzoo.uucp> Organization: U of Toronto Zoology References: <1989Nov26.223357.27453@utzoo.uucp> <4300@helios.ee.lbl.gov> Date: Tue, 28 Nov 89 06:09:57 GMT