Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!ub!kitty!larry
From: larry@kitty.UUCP (Larry Lippman)
Newsgroups: comp.dcom.modems
Subject: Re: Why do they insist on power cubes???
Summary: An annoyance, indeed...
Message-ID: <4293@kitty.UUCP>
Date: 4 Jan 91 18:05:05 GMT
References: <191@raysnec.UUCP>
Distribution: usa
Organization: Recognition Research Corp., Clarence, NY
Lines: 46

In article <191@raysnec.UUCP>, shwake@raysnec.UUCP (Ray Shwake) writes:
> 	What began as an annoyance has become a logistic mess. Some years
> ago, manufacturers of external modems like Hayes moved their power supplies
> to external power cubes which fit directly into the power line.

	There is a rather attractive design reason for going to external
power cubes - it vastly simplifies obtaining UL, CSA and VDE approval on
the modem since there is no AC power line voltage in the modem enclosure.

> 	Lately we procured a slew of Telebit T1000's - a low cost PEP/MNP
> modem. The unit itself is modest in size, but the external cube is a heavy
> monster almost the size of the old six-volt batteries, with long, heavy
> cables out both ends. Specs show the unit only draws 0.2 amps max.

	That's 0.2 amperes at 120 volts AC, with the bottom line being
that some watts do get dissipated.  Feel the T1000 power unit - it is
quite warm, and would be warmer yet if there were less surface area for
heat dissipation.

> The 
> units will fit nicely onto our computer room shelves, but now what do we
> do with the transformers???

	You could consider what we do: mount vertical strips of 2000-series
Wiremold having outlets on 6-inch centers, or buy pre-wired power strips
made by SGL/Waber.

> 	Given advances in micro-miniaturization - hey, they can fit
> transformer, electronics, and battery in your rechargeable razor - why do
> modem users have to suffer so? Perhaps engineering should spend less time
> on creating yet another protocol and a little more time on product design!

	Most power cubes are linear power supplies.  I don't see why more
designs using encapsulated switchers could not be made available.

	The ever-increasing size of power cubes is also a personal pet peeve.
I swear that modem manufactures hold an annual competition to see how large
a power cube they can shove down the throat of a customer! :-)

	I will never forget the first AT&T 2224B modem that we got in late
1984; it had the largest power cube I had ever seen at that time.  After I
opened the box and saw it, I just stood in awe...

Larry Lippman @ Recognition Research Corp.  "Have you hugged your cat today?"
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