mark@intek01.uucp (Mark McWiggins) (01/05/91)
shwake@raysnec.UUCP (Ray Shwake) writes: > 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. The >units will fit nicely onto our computer room shelves, but now what do we >do with the transformers??? I can see your problem, but I'm glad I had the power cube. A rogue UPS fried mine, and I was able to order another from Telebit for the grand total of $41.25 and be off to the races. Something in the case is no doubt harder to get to and harder/more expensive to repair. -- Mark McWiggins Integration Technologies, Inc. (Intek) +1 206 455 9935 DISCLAIMER: I could be wrong ... 1400 112th Ave SE #202 Bellevue WA 98004 mark@intek.com Ask me about C++!
larry@kitty.UUCP (Larry Lippman) (01/05/91)
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?" VOICE: 716/688-1231 {boulder, rutgers, watmath}!ub!kitty!larry FAX: 716/741-9635 {utzoo, uunet}!/ \aerion!larry
billd@fps.com (Bill Davidson) (01/05/91)
In article <191@raysnec.UUCP> shwake@raysnec.UUCP (Ray Shwake) writes: >manufacturers of external modems like Hayes moved their power supplies >to external power cubes which fit directly into the power line. A small >power lead then fed the small, stylish modem. [...] >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 [...] >with long, heavy cables out both ends. At least Telebit, and some others have quit putting the plug prongs directly on the power supply making it possible to now use all the outlets on a power strip instead of rendering every other outlet unusable due to being covered by a damned modem power supply (this is one of my pet peeves with all Hayes external modems I've seen and Microcom AX/2400c's). I have a large power distribution box but I can't plug all my damned Hayes modems into it because those stupid cubes block half the outlets. __ modem---------------|__| BAD || __ modem---------------|__|------------------|= GOOD I admit that I find it annoying trying to find a reasonable place for the external power supplies to live but at least I can plug the things in now. --Bill
dave@westmark.WESTMARK.COM (Dave Levenson) (01/06/91)
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. A small > power lead then fed the small, stylish modem. While some (like Prometheus) > kept to the internal power supply, most others followed the move to power > cubes. The first modem to have its power transformer mounted externally was the AT&T DataPhone 1200, also called the model 212 modem. This was the first full-duplex dial-up 1200 bps modem, and was also one of the first to be packaged in the new smaller size. Putting the transformer out side accomplished two purposes: It reduced the internal temperature of the modem enclosure. This is because the transformer tends to radiate more heat than most of the rest of the circuit. It allows a group of modems to be plugged into a rack, rather than being mounted in individual enclosures. A common power supply for the whole rack is less expensive than a bunch of individual transformers. Also, it keeps the high voltage contained close to the outlet or other power source. With no line voltage present on the modem circuit pack, less human-sheilding is required to meed safety requirements. The rack-mount strategy is expensive if you have 117 volts running around inside the rack! -- Dave Levenson Internet: dave@westmark.com Westmark, Inc. UUCP: {uunet | rutgers | att}!westmark!dave Warren, NJ, USA AT&T Mail: !westmark!dave [The Man in the Mooney] Voice: 908 647 0900 Fax: 908 647 6857
larry@kitty.UUCP (Larry Lippman) (01/06/91)
In article <139957@pyramid.pyramid.com>, lstowell@pyrnova.pyramid.com (Lon Stowell) writes: > Most vendors provide a rack mount type option which uses single > supply for a group of modems.... > > Although it is not rocket science to scrap the glob of power > cubes and just wire in a single commercial supply, I have a > hunch the FCC would cast a jaundiced eye...both from an > emissions/conduction view as well as (dial modems) protection of > the Public Switched Network.... I would not be overly concerned about an RFI emission problem (from a *practical* and not regulatory standpoint, however) provided that a powerline filter were installed on any common power supply. I have replaced power cubes with common power supplies and transformers, but a few words of caution are in order for reasons other than the above: 1. Many modems depend upon electrical isolation of their power cube, and tying more than one modem into a common DC power supply or AC transformer can result in serious impairment of the modem. As an example, some AT&T modem racks use a common transformer having independent *isolated* secondary windings. 2. Some modems have an internal rectifier and DC power supply, with the power cube being just a transformer. It may be a reasonable temptation to replace such a power cube with a DC power supply (say 12 volts, which is pretty common). While this will work in some cases (I have done it successfully), in others the modem rectifier arrangement is such that AC is *necessary* in order to obtain both a positive and negative internal DC supply. Larry Lippman @ Recognition Research Corp. "Have you hugged your cat today?" VOICE: 716/688-1231 {boulder, rutgers, watmath}!ub!kitty!larry FAX: 716/741-9635 {utzoo, uunet}!/ \aerion!larry
wb8foz@mthvax.cs.miami.edu (David Lesher) (01/06/91)
In <4299@kitty.UUCP> larry@kitty.UUCP (Larry Lippman) writes: > I have replaced power cubes with common power supplies and >transformers, but a few words of caution are in order for reasons other >than the above: >1. Many modems depend upon electrical isolation of their power cube, > and tying more than one modem into a common DC power supply or > AC transformer can result in serious impairment of the modem. > As an example, some AT&T modem racks use a common transformer > having independent *isolated* secondary windings. Anyone got any idea why my Microcom 2400's seem to want a center-tapped 19.6 volt xfmr, with the centertap connected to the ground pin of the power line. To my mind, that sacrifices the transformer isolation. -- A host is a host from coast to coast.....wb8foz@mthvax.cs.miami.edu & no one will talk to a host that's close............(305) 255-RTFM Unless the host (that isn't close)......................pob 570-335 is busy, hung or dead....................................33257-0335
jeffj@synsys.UUCP (Jeff Jonas) (01/06/91)
[] In article <14510@celit.fps.com> billd@fps.com (Bill Davidson) writes: >In article <191@raysnec.UUCP> shwake@raysnec.UUCP (Ray Shwake) writes: >>manufacturers of external modems like Hayes moved their power supplies >>to external power cubes which fit directly into the power line. A small >>power lead then fed the small, stylish modem. >At least Telebit, and some others have quit putting the plug prongs >directly on the power supply making it possible to now use all the >outlets on a power strip I recall a similar discussion with a friend who was busy getting a robotic toy ready for FCC certification. Some contries won't allow transformers hanging off the outlet. I agree - it places the weight of the power supply on the outlet and the prongs. These tend to fall out under their own weight if the outlet's well worn. Bad. Very bad. The power supply's weight should never bear on the electrical connection or the outlet box. My Racal Vadic modem power cube has a wire for the plug, so add one vender to the "good" list. A clever way to handle small power cubes is the Black and Decker Outlet Extender. It has three outlets spaced far enough apart for small transformers (as used by the Dustbuster) and it's covered. jeffj
jeffj@synsys.UUCP (Jeff Jonas) (01/06/91)
[] In article <139957@pyramid.pyramid.com> lstowell@pyrnova.pyramid.com (Lon Stowell) writes: >Most vendors provide a rack mount type option which uses single >supply for a group of modems.... My Penril rack holds 8 modems. The power supply is simply a card with 8 cubes. The cubes weren't modified at all. The card has an outlet for each, and standoffs are used for the output connection. The Micom rack holds 16 and used one power supply as you said. jeffj
root@zswamp.fidonet.org (Geoffrey Welsh) (01/07/91)
Larry Lippman (larry@kitty.UUCP ) wrote: >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. I'm sure it makes it much easier to engineer a reliable modem. Many moons ago, I owned a Prometheus Promodem 1200G (don't laugh - it was state of the art at the time!) and I was very pleased with the modem except that it had an internal power supply and tended to overheat and malfunction if left on all the time. -- UUCP: watmath!xenitec!zswamp!root | 602-66 Mooregate Crescent Internet: root@zswamp.fidonet.org | Kitchener, Ontario FidoNet: SYSOP, 1:221/171 | N2M 5E6 CANADA Data: (519) 742-8939 | (519) 741-9553 MC Hammer, n. Device used to ensure firm seating of MicroChannel boards Try our new Molson 'C' compiler... it specializes in 'case' statements!
neal@mnopltd.UUCP (01/07/91)
->> 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. A small
->> power lead then fed the small, stylish modem. While some (like Prometheus)
->> kept to the internal power supply, most others followed the move to power
->> cubes.
->
->
->The first modem to have its power transformer mounted externally was
->the AT&T DataPhone 1200, also called the model 212 modem. This was
->the first full-duplex dial-up 1200 bps modem, and was also one of
->the first to be packaged in the new smaller size.
->
->Putting the transformer out side accomplished two purposes:
->
->It reduced the internal temperature of the modem enclosure. This is
....
->
->It allows a group of modems to be plugged into a rack, rather than
->being mounted in individual enclosures. A common power supply for
....
It also leaves the vendor with one less detail when going international.
They can contract the little bricks from a supplier in each country. (of
course, they are still left with the phone line differences.)
------------------------------------------------------------------------------
Neal Rhodes MNOP Ltd (404)- 972-5430
President Lilburn (atlanta) GA 30247 Fax: 978-4741
emory!mnopltd!neal
gatech!emory!mnopltd!neal
------------------------------------------------------------------------------barefoot@hobbes.ncsu.edu (Heath Roberts) (01/08/91)
Most devices that connect to the public telephone network and are powered use this arrangement. The idea is that you don't want 120V AC in the same box with the telephone line, so you have a much less likely chance of frying a friendly telco employee, which they get very upset about. I doubt the FCC would approve any device using direct AC to connect to the PSTN unless it were very well built. Even most key telephone systems have separate power supplies (they may be in the same enclosure, but they are surrounded by metal). So the issue is basically one of safety to the telephone network and its minions... -- Heath Roberts NCSU Computer and Technologies Theme Program barefoot@catt.ncsu.edu
vernon@hpcvaac.cv.hp.com (Vernon King) (01/09/91)
Another reason for the proliferation (sp?) of external power supplies is the
fact that if you buy a power supply from an external vender it makes fcc cert-
ification much easier. The vendor must certify the power supply with the fcc.
I personally hate them but I do understand why people use them.
Vernonpaulg@frith.uucp (Gregory R Paul) (01/11/91)
In article <6597.2788009C@zswamp.fidonet.org> root@zswamp.fidonet.org (Geoffrey Welsh) writes: >Larry Lippman (larry@kitty.UUCP ) wrote: > > >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. > > I'm sure it makes it much easier to engineer a reliable modem. Many moons >ago, I owned a Prometheus Promodem 1200G (don't laugh - it was state of the art >at the time!) and I was very pleased with the modem except that it had an >internal power supply and tended to overheat and malfunction if left on all the >time. > I'm surprised that no one has mentioned that silly modem that Apple made a while back (I at least hope it was a while back now..) that had the actual prongs on the modem itself and was basically designed to dangle from a wall outlet. > >-- >UUCP: watmath!xenitec!zswamp!root | 602-66 Mooregate Crescent >Internet: root@zswamp.fidonet.org | Kitchener, Ontario >FidoNet: SYSOP, 1:221/171 | N2M 5E6 CANADA >Data: (519) 742-8939 | (519) 741-9553 >MC Hammer, n. Device used to ensure firm seating of MicroChannel boards >Try our new Molson 'C' compiler... it specializes in 'case' statements! -- Greg Paul | Electrical/Computer Engineer in search of a job.. paulg@frith.egr.msu.edu | Case Center Consultant | "and she never had dreams... sysop: Sietch Tabr | so they never came true.."
necka@motcid.UUCP (William J. Necka) (01/16/91)
In article <1991Jan11.012923.814@msuinfo.cl.msu.edu> paulg@frith.uucp (Gregory R Paul) writes: > I'm surprised that no one has mentioned that silly modem that Apple made ^^^^^ ^^^^^ >a while back (I at least hope it was a while back now..) that had the actual >prongs on the modem itself and was basically designed to dangle from a wall >outlet. > Just when you thought it was safe, tha thum, tha thum.... silly modem 2. Have you seen the little hayes modem they are selling thru Service Merchindise, a popular catalog wholesaler here in the US? They must have gotten the idea from apple. I heard it works fine from a friend who got one when he signed up for PRODIGY, but they are a little pricey. ______________________________________________________________________________ ------------------------------------------------------------------------------ -- x || William Necka - __/ \__/\/\/\/ \____ Motorola Cellular || uunet!motcid!necka / \__/ \ _/ [][\_ Arligton Heights Il. || Opinions expressed are not \__/ \__/ (________) 708-632-4435 || necessarily my employer's. _____\__/__________()__()________________________||____________________________ -------------------------------------------------------------------------------
tnixon@hayes.uucp (01/17/91)
In article <6189@khaki8.UUCP>, necka@motcid.UUCP (William J. Necka) writes: > Just when you thought it was safe, tha thum, tha thum.... > silly modem 2. Have you seen the little hayes modem they are selling > thru Service Merchindise, a popular catalog wholesaler here in the > US? They must have gotten the idea from apple. I heard it works fine > from a friend who got one when he signed up for PRODIGY, but they > are a little pricey. Those modems were designed precisely to Prodigy's specifications. They were looking for something that would fit the profile of the targetted Prodigy audience -- in other words, has to absolutely as simple as possible, with _zero_ telecom/datacom knowledge needed in order to make it work. Perhaps they did get the idea from Apple, but I suspect it was more based on extensive market research and focus groups (like everything else that Prodigy has done). -- Toby Nixon, Principal Engineer | Voice +1-404-449-8791 Telex 151243420 Hayes Microcomputer Products Inc. | Fax +1-404-447-0178 CIS 70271,404 P.O. Box 105203 | UUCP uunet!hayes!tnixon AT&T !tnixon Atlanta, Georgia 30348 USA | Internet hayes!tnixon@uunet.uu.net
tech@mich-ns.UUCP (Mich. Network Sys. TECH SUPPORT) (02/28/91)
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. A small
"power lead then fed the small, stylish modem. While some (like Prometheus)
"kept to the internal power supply, most others followed the move to power
"cubes.
"
" 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. The
"units will fit nicely onto our computer room shelves, but now what do we
"do with the transformers???
"
" 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!
"
The Telebit power supplies are made by a separate company. Yes, I agree
that they should have some sort of device with ONE of these "bricks"
and a "power strip" into which you can plug, say, 8 or 10 modems. In
the mean time, you could always buy the Rackmount units and pay an extra
$1k for the rack unit. ;-> (The modems themselves are cheaper in rackmount
than the standalone's are).
John
--
Michigan Network Systems Technical Support Division
Telebit/SCO/Digiboard Reseller BBS: +1 313 343 0800
1-800-736-5984pda@Dixie.Com (Paul D. Anderson) (03/01/91)
>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. A small
] power lead then fed the small, stylish modem. While some (like Prometheus)
] kept to the internal power supply, most others followed the move to power
] cubes.
] [...]
] 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!
It is actually more likely due to getting UL approval: a long,
complicated, expensive, political process.
You see, if I am a manufacturer of computer peripherals, and I
run AC into a unit, then I really need to get UL approval on
that unit. If I buy a brick that is already UL approved, then
it is one less nightmare that I have to go thru before getting
to market. And it costs me a hell of a lot less.
Frankly, it probably has more to do with going to court than anything.
Imagine the following scenario, where a modem caused a building fire:
The prosecution attorney: "Mr. Manufacturer, you're
product was not UL approved. Why is that?"
"We needed to save costs."
"Oh, and as such you skimped on engineering, causing
a building fire..."
Versus using a wall cube:
The defense attorney: "Mr. Manufacturer, your modem
power supply caused a building fire. Why is that?"
"The power supply, supplied by another vendor did.
But it was a well designed power supply."
"Why do you say that?"
"It was an Underwriters Labratory approved device. They have
*National* standards established to guarantee the safety of
people and property. The manufacturer spent many thousands of
dollars to guarantee that that device was safe, rigourously tested
the device and submitted it for additional testing and approval.
UL has done this for years and is recognized as *the* authority
on such matters."
"So..."
"So if this device failed, it is probably due to misuse by the
client. OR a manufacturing defect. But we sought out the best
engineering possible, backed by a National Laboratory
Certification, to guarantee our clients safety. We went the
full ten yards to make sure he was safe..."
In other words, buying and reselling power cubes is a form of
insurance. And a darn good one. Unfortunately, it results in
messes of cables, inefficient use of power, etc. But, in
today's litigious society, for a business to stay in business,
it means knowing *exactly* where you will get intro trouble
with the courts. And for a startup or small to medium size
business, one good lawsuit, while it may or may not be
financially crippling, will encumber the principle players
enough that the business may flounder.
-paul
--
* Paul Anderson * Dixie Communications * (404) 578-9547 * pda@dixie.com *james@netcom.COM (James Paul) (03/01/91)
In article <14@mich-ns.UUCP> tech@.UUCP (Mich. Network Sys. TECH SUPPORT) writes: >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. A small >"power lead then fed the small, stylish modem. While some (like Prometheus) >"kept to the internal power supply, most others followed the move to power >"cubes. >" >" 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. The >"units will fit nicely onto our computer room shelves, but now what do we >"do with the transformers??? >" >" 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! >" > >The Telebit power supplies are made by a separate company. Yes, I agree >that they should have some sort of device with ONE of these "bricks" >and a "power strip" into which you can plug, say, 8 or 10 modems. In >the mean time, you could always buy the Rackmount units and pay an extra >$1k for the rack unit. ;-> (The modems themselves are cheaper in rackmount >than the standalone's are). > >John > Or, you could simply use another power supply. These "power cubes" are more commonly known as wall transformers or AC adapters. They usually consist of a single step-down transformer in the 9 to 12 volt range. Some rectify the AC to DC, filtering with a single capacitor. If you have 10 0.2amp modems that run on 12vdc for example, just wire up a harness with 10 connectors and run the modems off any supply. You can get power supplies in that range rated at 5 amps or more for $10. (Or a few $ more at Radio Shack :-) Also, you can pay a few more $ to get a good regulated supply. Most wall transformers are cheaply made and don't live long. Many of them are rated for less power than the device needs. (I have bought lots of things that draw 600-900ma, but come with a 500ma cube.) I usually hack off the connector and use another supply. (I have lots of stuff that's on continously.) -- James L. Paul UUCP: james@netcom.COM | AppleLink: D1231 | America Online: JLPaul Packet: N6SIW@N6EEG.CA.USA.NA | GEnie: J.PAUL | CompuServe: 72767,3436 Voice: 415 377 1981 w/machine | Delphi: JLPaul | Home Fax: 415 377 0381
enger@seka.scc.com (Robert M. Enger) (03/03/91)
An all around nicer approach is to use rack-mount card-cage modems. This makes for a very small installation, consolodated wiring, and often redundanct power supplies. I'm sure many folks have considered this, but I have not seen it mentioned in the thread so far. I realize that this is not a solution for folks already loaded down with lots of desk top units. Bob -- Robert M. Enger CONTEL Federal Systems enger@seka.scc.com (Internet)
bill@bilver.uucp (Bill Vermillion) (03/04/91)
In article <26284@netcom.COM> james@netcom.COM (James Paul) writes: >In article <14@mich-ns.UUCP> tech@.UUCP (Mich. Network Sys. TECH SUPPORT) writes: >>The Telebit power supplies are made by a separate company. Yes, I agree >>that they should have some sort of device with ONE of these "bricks" >>and a "power strip" into which you can plug, say, 8 or 10 modems. >Or, you could simply use another power supply. These "power cubes" are >more commonly known as wall transformers or AC adapters. They usually >consist of a single step-down transformer in the 9 to 12 volt range. >Some rectify the AC to DC, filtering with a single capacitor. T'bit's ouputs are 18 vac with a 25va rating. Not quite the same as some of the "el cheapo" modem power supplies - and they even used grounded plugs! >If you have 10 0.2amp modems that run on 12vdc for example, just wire >up a harness with 10 connectors and run the modems off any supply. You >can get power supplies in that range rated at 5 amps or more for $10. >(Or a few $ more at Radio Shack :-) Also, you can pay a few more $ to >get a good regulated supply. But be sure you put protection on each individual modem connection. All you need is a catastrophic power supply failure and you have 10 dead modems. -- Bill Vermillion - UUCP: uunet!tarpit!bilver!bill : bill@bilver.UUCP