tomm@hpspdra.spd.HP.COM (Tom Menten) (05/06/91)
(With apologies, if this is an old question.) I would like to find take a laptop on a fishing boat; it needs to run from the 12v system on the boat, since there is no regular access to 120v AC. Surely, there must be many users running their laptops from car batteries, yes? Yet folks at the local computer warehouse type store seem to think this is an esoteric question. Are there standard solutions someone can tell me about? Regards, Tom Menten
gettys@yacht.enet.dec.com (Bob Gettys) (05/10/91)
A lot of laptop manufacturers sell car adaptor cords. For example, my Toshiba T1000LE has a cord available from Toshiba. The Laptop runs on 12v and the cord allows you to plug it into a cigarette lighter plug (cost - about $100). I questioned the cost, untill I looked at what I was buying - it's a full DC-DC converter designed to fully isolate you from the vagries of the car electrical system and charge the laptop battery (which is 12v) when the car output is below that of the ni-cad. If your laptop ac supply puts out less than about 10 volts, it would be fairly easy to build a 12v to "x"volt voltage regulator with appropriate filtering and overvoltage and spike protection. If you don't feel comfortable with that, I have seen advertised small dc to ac (115v output) converters designed just for this purpose. You plug it into the 12v source, the laptop ac adaptor into it, and the laptop into the normal power supply. /s/ Bob Gettys
andrew@frip.WV.TEK.COM (Andrew Klossner) (05/10/91)
"I would like to find take a laptop on a fishing boat; it needs
to run from the 12v system on the boat, since there is no
regular access to 120v AC."
If it's a Toshiba, you can get a car cigarette lighter power adapter
that takes 12VDC in and puts out whatever the laptop needs. Try a
local Toshiba dealer or Toshiba Accessories Direct, (800) 999-4823.
-=- Andrew Klossner (uunet!tektronix!frip.WV.TEK!andrew) [UUCP]
(andrew%frip.wv.tek.com@relay.cs.net) [ARPA]cpetterb@glacier.sim.es.com (Cary Petterborg) (05/16/91)
In article <18820001@hpspdra.spd.HP.COM> tomm@hpspdra.spd.HP.COM (Tom Menten) writes: > I would like to find take a laptop on a fishing boat; it needs to > run from the 12v system on the boat, since there is no regular > access to 120v AC. > > Surely, there must be many users running their laptops from car > batteries, yes? Yet folks at the local computer warehouse type store > seem to think this is an esoteric question. Are there standard > solutions someone can tell me about? I saw in a magazine (or catalog) a converter which you could plug into a car cigarette lighter and get 110V AC out. Anyone else know about one of these things? Do they work very well (low wattage output if I remember), or do they drain the car battery too much? Does anyone know where you can get one? Cary -- _______________ Cary Petterborg (801)582-5847 x6446 Evans & Sutherland Computer Corp. Simulation Division SLC, UT 84108 UUCP: ...!uunet!sim.es.com!cpetterb *NET: cpetterb@glacier.sim.es.com _______________ "A heart is not judged by how much you love, but by how much you are loved by others." -Wizard of Oz
dpbst3@unix.cis.pitt.edu (David P Brennan) (05/16/91)
In article <CPETTERB.91May15171332@mickey.glacier.sim.es.com> cpetterb@glacier.sim.es.com (Cary Petterborg) writes: >In article <18820001@hpspdra.spd.HP.COM> tomm@hpspdra.spd.HP.COM (Tom Menten) writes: > >I saw in a magazine (or catalog) a converter which you could plug into >a car cigarette lighter and get 110V AC out. Anyone else know about >one of these things? Do they work very well (low wattage output if >I remember), or do they drain the car battery too much? Does anyone >know where you can get one? > The thing you're talking about is a "voltage inverter" - Radio Shack has been selling these things for years, as have any electronics supply companies. All it is (basically) is a transformer that steps 12V to 110V with a few rectifiers and assorted filters. Not having used one, I can't say how well it would work for an extended period. I would assume (and I'm sure I'll be corrected if I'm wrong :-) ) that it would be most efficent if the alternator were running from whatever 12V source you're using. Tough on a boat in the middle of a lake, eh? :-) Dave Brennan UPitt SLIS dpbst3@unix.cis.pitt.edu +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Question: If you were locked in a room with Saddam, the Ayatollah, and a lawyer and your gun only had two bullets, who would you shoot? Answer: Shoot the lawyer twice. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
tomm@hpspdra.spd.HP.COM (Tom Menten) (05/20/91)
|In article <CPETTERB.91May15171332@mickey.glacier.sim.es.com> cpetterb@glacier.sim.es.com (Cary Petterborg) writes: |> |>I saw in a magazine (or catalog) a converter which you could plug into |>a car cigarette lighter and get 110V AC out. Anyone else know about |>... |> |The thing you're talking about is a "voltage inverter" - Radio Shack has |been selling these things for years, as have any electronics supply companies. |All it is (basically) is a transformer that steps 12V to 110V with a few |rectifiers and assorted filters. Well, this weekend, I heard the "voltage inverter" (12DC to 110AC) described as a preferred solution, allowing all sorts of things to be plugged in. Then I spoke with a technical support person for one of the mail order laptop companies who pointed out some problems: apparently the inverters (at least some of them, presumably including the less expensive variety most of us would consider purchasing) cause a radio frequency "hash" that could cause problems for some plugged in appliances, and also for nearby electronics (especially boat electronics!) He was much more comfortable with generating systems than inverters. The bay area doesn't seem to have much retail expertise in marine electronics; I'll probably call around in Seattle and post a followup note.
dpbst3@unix.cis.pitt.edu (David P Brennan) (05/20/91)
In article <18820003@hpspdra.spd.HP.COM> tomm@hpspdra.spd.HP.COM (Tom Menten) writes: > > Well, this weekend, I heard the "voltage inverter" (12DC to 110AC) > described as a preferred solution, allowing all sorts of things to > be plugged in. Then I spoke with a technical support person for one > of the mail order laptop companies who pointed out some problems: > apparently the inverters (at least some of them, presumably including > the less expensive variety most of us would consider purchasing) cause > a radio frequency "hash" that could cause problems for some plugged in > appliances, and also for nearby electronics (especially boat electronics!) > He was much more comfortable with generating systems than inverters. > I had posted the original description about the voltage inverter and after checking into it a bit further I would caution against trying to use one to power ANY computing equipment. The product listing in MCM Electronics' catalog (Dayton,OH) includes a warning to not use a voltage inverter with any microprocessor-based device, including computers. Apparently inverters do not put out a stable level of power. They are designed to provide site power for drills, saws, pumps etc. Things that don't particularly care what kind of power they get. Trying to run a laptop in a boat seems to be a unique and difficult problem to solve....I think it might be a good idea to just invest in 3-4 extra battery packs and charge them before going out. Dave Brennan UPitt SLIS dpbst3@unix.cis.pitt.edu
logier@cheops.qld.tne.oz.au (Rob Logie) (05/21/91)
I remember that with some of the early laptops that were released you could buy a adaptor that ran off the lighter in the car to power the laptop. Do any manfacturers still make such a thing ??. regards -- Rob Logie EMAIL: logier@cheops.qld.tne.oz.au Telecom Australia FAX: +61 7 837 4704 TNE Computer Support Services PH: +61 7 837 5174 Brisbane Office "These are my opinions alone"
ariel@seer.UUCP (Catherine Hampton) (05/21/91)
I have a car battery power unit for my Toshiba T-5100, and have used a similar unit with a Toshiba T-1000SE and T-1200HB. I find that I like to have an extension cord available, so that I can sit outside the car (at a picnic table, for example) and use the computer, but otherwise I haven't had any trouble with any of these set-ups. They work well. Cathy Hampton ariel@seer.mystic.com
stecz@hotwheel.dell.com (John Steczkowski) (05/22/91)
In article <1991May20.221402.24682@cheops.qld.tne.oz.au>, logier@cheops.qld.tne.oz.au (Rob Logie) writes: > I remember that with some of the early laptops that were released you > could buy a adaptor that ran off the lighter in the car to power the laptop. > > Do any manfacturers still make such a thing ??. > Dell has a car adaptor for their laptops. John Steczkowski stecz@hotwheel.dell.com || uunet!dell!hotwheel!stecz Dell Computer Corp., 9505 Arboretum Blvd., Austin, Texas, 78759 - "It is better to go into a corner slow and come out fast, - - than to go into a corner fast and come out dead." Stirling Moss -
davidc@vlsisj.uucp (David Chapman) (05/22/91)
In article <1991May20.221402.24682@cheops.qld.tne.oz.au>, logier@cheops.qld.tne.oz.au (Rob Logie) writes: |> I remember that with some of the early laptops that were released you |> could buy a adaptor that ran off the lighter in the car to power the laptop. |> |> Do any manfacturers still make such a thing ??. I have a (brand new) Librex 386SX laptop, and the dealer tells me that the 12V adapter will be available "Real Soon Now" (i.e. next month). I think the main problem is that most laptops want a bit more than 12V in, and the adapter would have to boost the voltage. There's no reason they shouldn't be able to do it (or me, for that matter) but I guess they don't think it's worth the bother. David Chapman {known world}!decwrl!vlsisj!davidc vlsisj!davidc@decwrl.dec.com
userDHAL@mts.ucs.UAlberta.CA (David Halliwell) (05/22/91)
In article <18820003@hpspdra.spd.HP.COM>, tomm@hpspdra.spd.HP.COM (Tom Menten) writes: >|In article <CPETTERB.91May15171332@mickey.glacier.sim.es.com> cpetterb@glacier.sim.es.com (Cary Petterborg) writes: >|> >|>I saw in a magazine (or catalog) a converter which you could plug into >|>a car cigarette lighter and get 110V AC out. Anyone else know about >|>... >|> >|The thing you're talking about is a "voltage inverter" - Radio Shack has >|been selling these things for years, as have any electronics supply companies. >|All it is (basically) is a transformer that steps 12V to 110V with a few >|rectifiers and assorted filters. > > Well, this weekend, I heard the "voltage inverter" (12DC to 110AC) > described as a preferred solution, allowing all sorts of things to > be plugged in. Then I spoke with a technical support person for one > of the mail order laptop companies who pointed out some problems: > apparently the inverters (at least some of them, presumably including > the less expensive variety most of us would consider purchasing) cause > a radio frequency "hash" that could cause problems for some plugged in > appliances, and also for nearby electronics (especially boat electronics!) > He was much more comfortable with generating systems than inverters. > One consideration in looking at "cheap" inverters is the type of waveform output. I believe that some generate a square wave instead of a sine wave. (This at least used to be true for uninterruptable power supplies from some manufacturers.) If so, you may want to confirm that your laptop will be happy with a square wave output. All this discussion has been oriented toward provision of 110V AC power. I assume that the laptop in question requires AC power and does not run off a battery. For people with battery-powered laptops, check the voltage level provided by the battery. If it is a 12V system, then you can hook it up to a car battery directly. All you need is a cable that plugs into your DC input (likely where the charger attaches) and has clips to hook up to the battery terminal. Make sure the polarity is correct! I have run my Zenith this way for hours, with the battery hooked up to a solar panel for recharging. (AC power was 5 miles away, across a river, with only a footpath for access. Can you say "3 hour cruise"?) For non-12V systems, you may want to be careful. 12V may be all right if applied to a charging connection (the charger MUST put out more volts than the nominal battery rating to charge it), but if a DC connector is hooked directly to the computer guts, a high voltage may fry it. You would then need a DC-DC step-down transformer. These are easy to find (e.g Radio Shack) if you need less than 500-800 mA, but if you need more then it can be a bit tough. Does anyone else have success or failure stories about running computers off solar panels or other alternate DC sources for long periods of time? Dave Halliwell
acrosby@uafhp.uark.edu (Albert Crosby) (05/23/91)
Yup, using most inverters with computer equipment is not a good idea. However, there are some that work. The solid state inverters can't produce a stable output, but most of the ones that are not solid state work okay. (My dad holds the patent for one of these... not making it, but others do make similiar devices.)
bks@shiva.Berkeley.EDU (Brian K. Shiratsuki) (05/23/91)
In article <RN.1238@mts.ucs.UAlberta.CA> userDHAL@mts.ucs.UAlberta.CA (David Halliwell) writes: > All this discussion has been oriented toward provision of 110V AC >power. I assume that the laptop in question requires AC power and does >not run off a battery... i was wondering about all this discussion of inverters, too, unless the original question was about an old grid or somesuch. my machine (no hard disk) is supposed to draw 1.1A at nine volts. so it seems to me i could use a solid-state series-pass regulator along with the car electrical system. it would need enough heat sink to dissipate, say, four watts. if you're not into building such gadgets, then i would look to see if radio shack had something capable of supplying the current. brian
quimby@madoka.its.rpi.edu (Quimby Pipple) (05/23/91)
bks@shiva.Berkeley.EDU (Brian K. Shiratsuki) writes: >i was wondering about all this discussion of inverters, too, unless >the original question was about an old grid or somesuch. my machine >(no hard disk) is supposed to draw 1.1A at nine volts. so it seems >to me i could use a solid-state series-pass regulator along with the >car electrical system. it would need enough heat sink to dissipate, >say, four watts. It is pretty simple to do, but keep in mind that an automotive electrical system is sometimes electrically nasty. One tech sheet lists surges of -50 to +80 V @ 100 msec, and 200-400V microsecond range transients as possible. Newer cars probably aren't this bad, but it wouldn't hurt to put some sort of protective circuitry in front of the 3 terminal regulator. Maybe a fuse, series diode, transorb or MOV, and cap. The 3 terminals are usually pretty bulletproof, though. Quimby -- quimby@mts.rpi.edu, quimby@rpitsmts.bitnet -- quimby@mts.rpi.edu, quimby@rpitsmts.bitnet
RWC@psuvm.psu.edu (05/25/91)
About inverters. I've used a Statpower Pocket inverter available through West Marine (1800 538-0775) with both Zenith and Tandy laptops with no trouble. It's a high quality unit, costing about $150, with a 100 watt output. I too was concerned about the wave-form...one of Statpower's engineers told me that not only would the inverter not cause a problem, but that Toshiba was specifically recommending it for their laptops. All I can say is that it gives me no trouble and has a nice feature of warning you if you risk pulling too much power from your battery. Colman Penn State--Harrisburg
dan@rna.UUCP (Dan Ts'o) (05/26/91)
In article <91145.073228RWC@psuvm.psu.edu> RWC@psuvm.psu.edu writes: >About inverters. I've used a Statpower Pocket inverter available through West >Marine (1800 538-0775) with both Zenith and Tandy laptops with no >trouble. From the back of Byte magazine, a company that advertises laptop power supplies, both AC and DC input: Product R&D Corp. 805-546-9713 They apparently also have various option cards for laptops, like FAX/modems, etc.
barr@frog.UUCP (Chris Barr) (05/29/91)
In article <RN.1238@mts.ucs.UAlberta.CA>, userDHAL@mts.ucs.UAlberta.CA (David Halliwell) writes: > Does anyone else have success or failure stories about running > computers off solar panels or other alternate DC sources for long > periods of time? Yes, a friend of mine has, for about 2 years, used solar panels to power an early model Zenith 386 laptop (in the south of France where sun is plentiful), for weeks at a time. He's also used automobile battery converters. One interesting one he looked at, don't know if he bought it, was called Power Trip, by a company called Xirco. These things dissipate heat, and the better ones, i.e. higher-wattage ones, are recommended to NOT be attached thru a cigarette lighter, but directly to the battery. 100 watts seems to be a threshold. Here's my list of companies selling automobile-battery power supplies for laptops, but I have no experience to report. About 18 mos. old: Xirco Inc.: Wheat Ridge, CO 303/421-2013 $179 for 100W inverter 'Power Trip' StatPower, 604-420-1585, 170 Simundson Dr., Point Roberts WA 98281 $122/230 Axonix: Utah, 801/466-9797 laptop specialist, fax 485-6204 Chris Barr Charles River Data Systems, Framingham, MA