Car Adapter

[zazonz]

Anyone know a good car adapter for the T22. The cheaper the better. Thanks in advance.

[dsvochak]

I think the most useful device is a power adaptor (a cigarette lighter plug with an outlet on the other end). That way you can plug anything in, not just the thinkpad.

[Leon]

called an Inverter.. for sale at Radio Shack and almost all electronic stores....

[ian]

This is of course nonsense - it IS NOT unversally called an Inverter (what is there to "invert"?) but more usually a power adaptor.

Can't believe anything one reads nowadays...

[Leon]

hi ian:

the device that dsvochak was referring to (one which you can plug anything into) IS most commonly called an Inverter... here is a link to the Radio Shack Site with these devices in the category on Inverters. "Adapters" is a much more general category including MANY devices that will NOT let you plug an AC device into...

http://www.radioshack.com/category.asp? ... 000&Page=1

Regards,

Leon

[ian]

Your so [censored] keen on increasing your total number of posts you forget to read the questions - the guy is looking to power a laptop NOT a lawnmower - why on earth anyone would want to power a laptop from AC current I can't possibly imagine - no doubt, WE will be enlightened with your response.

A helpful hint:- if you break up your response into lots of short posts your total will soar - try it. Best of all, try actually reading the original post before replying, and give us all a break.

[Leon]

again, ian, I was trying to be helpful in clarifying dsvochak's response... if you didn't find it helpful, no need to be shirty..... I have no desire to "increase my number of posts" (there is no prize for that ).... I spend a significant amount of time reading, moderating, and trying to add value to this forum...I also appreciate the value that you add... if you don't find my replies useful, you are welcome to ignore them, but emotional responses are never in order (that is what private messages are for).. sorry if you are having a bad day... if you must continue this, please do it in the form of a private message....

[Kenn]

This is of course nonsense - it IS NOT unversally called an Inverter (what is there to "invert"?) but more usually a power adaptor.

This should be a generally inexpensive and practical solution. Getting a general purpose inverter for < $50 is cheaper and more useful than shelling out for the huge AC/DC transformer from IBM, though that one allows you to use the DC power out available on Airbus planes

It's called an inverter because it does the opposite of what a traditional power transformer does - it converts direct current "back" to AC, which of course is transformed back to the correct DC voltage/amps by the thinkpad power brick. Maybe not the most direct route, but again, pretty inexpensive given the alternatives.

[JHEM]

This is of course nonsense - it IS NOT unversally called an Inverter (what is there to "invert"?) but more usually a power adaptor.

The item described "I think the most useful device is a power adaptor (a cigarette lighter plug with an outlet on the other end). That way you can plug anything in, not just the thinkpad" is most certainly an inverter.

It inverts DC to AC.

Automobile power adapters take in 12V DC and give out a differing voltage of DC, sometimes higher, sometimes lower.

Regards,

James

[dsvochak]

The last couple of responses were what I intended. I originally bought the device @ 5 years ago to run a DeWalt Power tool battery charger (it's useful for charging batteries on a job site). You can just leave the thing in the car. I also used it during the '03 blackout to recharge rechargable batteries for flashlights. radios, etc. My whole point waa, if you're looking for something to use in your car, an inverter/adaptor has more uses than a device just to run your notebook.

[jdhurst]

<snip>... why on earth anyone would want to power a laptop from AC current I can't possibly imagine - no doubt, WE will be enlightened with your response.

I use a DC-AC inverter power supply to create AC power in the car. Why?

(a) It will power any laptop, not just my own, and that has been convenient.
(b) It will power my cell phone charger/adapter, and that has been a "life" saver when the battery in the phone dies.
(c) It will do the above (and other things) simultaneously.

So it is not efficient, and it is not small, but it gives me flexibility I would otherwise not have. It's a personal opinion / decision, and another person might be better served by a proper car adapter.
... JD Hurst

[syhead]

yep, inverter is the best choice...

[ian]

I find it totally amazing that it's taken me 47 years to learn the difference between AC and DC current.

There I was, floating lost in the wilderness when BAMM! God gave us Leon and despite his banal, sometimes fatuous, and often condescending posts, I've learned the error of my ways (which in fact wasn't an error at all, but who cares if no-one actually READS the posts)

Thank you Leon, thank you for, well, everything really - power inverters, sliced bread, disposable diapers - the lot. I'll never question your word ever again - after all "we" know where it comes from...

The end

[jdhurst]

I find it totally amazing that it's taken me 47 years to learn the difference between AC and DC current.
<snip>

And different beasts they are! The peak value of a DC voltage is its stated voltage. The stated voltage of an AC source is usually RMS value and the Peak-to-Peak value of the same AC source is nearly three times that. That is why AC line cords and plugs (especially in Europe) need to be especially well designed with highly rated insulation. Cheers.
... JD Hurst

[ehd]

make sure the inverter u get has enough voltage.. i had to buy 2.. yea i got em on ebay so they were cheap but dont get the one that sticks directly into ur cigarette thing without a cable.. get the one that has a cable to ur cigarette thingy so u can put the block plug thing in farther away.. if that made sense

[krosenstein]

Your so [censored] keen on increasing your total number of posts you forget to read the questions - the guy is looking to power a laptop NOT a lawnmower - why on earth anyone would want to power a laptop from AC current I can't possibly imagine - no doubt, WE will be enlightened with your response.

A helpful hint:- if you break up your response into lots of short posts your total will soar - try it. Best of all, try actually reading the original post before replying, and give us all a break

I have no desire to "increase my number of posts" ...I also appreciate the value that you[Ian] add... .

I must contribute, albeit reluctantly, to this bickering. This forum has provided me with significant help and useful information in the year that I've been visiting. Most, but not all, comes from a handful of regular posters. I've never gotten the impression that anyone has been trying to pump up their numbers.

But, Ian, one thing I've noticed is that, for all your posts, you rarely contribute anything useful. You nitpick about things that I'm sure are important to you, but only your arrogance would lead you to believe that they're relevant to the topics discussed in this forum. More important, many of your comments are harsh and personal and even mean-spirited. Maybe you find them funny, but I doubt others do. I don't usually make personal negative posts like this and apologize to the other readers, but your reaction to Leon went over the line and cried out for a more blunt response, even though he's a big boy and doesn't need me to defend him.

[gte204i]

Disclaimer: I don't really have any hard facts here ...

... BUT I would be careful with those cheap "inverters." Some of produce waveforms that look more like square waves than sine waves. This is BAD for your sensitive electronic equipment (i.e. laptops) because it introduces high frequency harmonics into the power supply. The TP power brick may help filter some of this out - I really don't know. That said, I know people who have run laptops off of these "inverters" for years without problems.

I would probably rather spend the money on a good DC adapter rather than going DC -> AC -> DC. But I really can't absolutely say that it will cause you problems.

[jdhurst]

I agree that one should buy a good quality inverter, and also that it should fit one's particular circumstances. It fits mine. I have a Port inverter that rates at 140 Watts output. I have never had any difficulty with it.

But it is (like all of these) a simple minded inverter. I took it down to my modest lab in the basement and it produces a stepped square wave. Since the power brick is itself a switched power supply, it probably is OK. As I said, I haven't had any problems. I doubt you would ever find a consumer DC -> AC inverter that produces a sine wave. Good quality, as you note, is highly important.
... JD Hurst

[carbon_unit]

I bought a couple of these:
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 6736340009
They seem OK.

[kev009]

I'm uneasy using the inverter method. None of these output true sine wave AC or even anything close to clean power. Does the TP power brick help make this a non issue or will it casue any downfalls to the brick or notebook? Someone with electrical/electronics experience please.. no "mine works" posts.

[zazonz]

Thanks for the replys.

[JonathanGennick]

On a recent trip, I purchased one of these:

http://apc.com/resource/include/techspe ... u=TPA90DC

It's from APC, and it converts 12-volt car-voltage into any of a selection of output voltages that you select by twisting a dial. It comes with a set of interchangeable tips to fit many laptop brands. I can even order a tip to fit my cellphone, though, annoyingly, that tip didn't come with the unit.

I bought this for my nine-year-old who wanted very much to play his new computer game in the backseat on the way home. The APC unit was a bit pricey, but, I think, well-worth the expense. It kept my nine-year-old occupied for much of the trip (good!), and it'll give me a spare to use here at home when I (occasionally) leave my Thinkpad adapter in a hotel room.

The unit gets hot though. Much hotter than IBM's power supply.

APC sells an inverter too, but it seemed silly to me to convert from 12 volts DC to 120 volts AC and then back again to a low, DC voltage.

[Leon]

....one of the great values of this forum... a seemingly simple question in the original post has blossomed into a discussion that adds value to our repertoire of knowledge, and perhaps will come to some heretofore unknown useful conclusion.....

so, here's where we stand vis-a-vis inverters:

1. Anecdotal evidence
With due acknowledgment of kev009's comment, I DO believe that the anecdotal evidence supports the fact that using one does no harm. I, for one, HAVE used one extensively for years in the car while being driven between Boston and new York. Neither adapter nor Thinkpad have seemingly suffered any ill effects. Not meant to be conclusive in any way, but a data point.

2. Professional Opinion
I AM a EE (by education, but not by trade). It is my opinion that the electronics of the adapter will be a sufficient buffer to the output of the inverter as to make the output the Thinkpad receives ok. However, I solicit (and welcome) opinions from others with more recent or specific experience.

3. Evidence
We need to "see" the output from the Adapter, both while plugged into standard AC, and while plugged into an Inverter. I would, but don't have the equipment. Anyone care to volunteer? I won't name names (so as not to put anyone on the spot), but I seem to remember that a member whose name begins with "j" has a scope. Maybe he shall be so gracious as to volunteer.

zazonz, welcome (back) to the world of posting

krosenstein, you have a private message

dsvochak, syhead, ehd, baraider, kev009, and JonathanGennick (in some cases somewhat belated): Welcome to our Forum and extended "Family" (we DO tend to act like a real Family sometimes ).

Thanks to everyone for your continuing contributions.

[JHEM]

Anyone care to volunteer? I won't name names (so as not to put anyone on the spot), but I seem to remember that a member whose name begins with "j" has a scope.

But no pressure, right!

The IBM brick is designed to take AC in that may be derived from burning cow dung outgases in a small automotive engine driving an alternator with the AC output tapped.

An inverter, regardless of how dirty the output, will do no harm provided the output is sufficient to match the IBM brick.

Regards,

James

[jdhurst]

I already posted in this thread about the inverter ouput. It is a stepped square wave: positive voltage for a bit, zero voltage for a bit and negative voltage for a bit. The bits are equal in length (time), and the total of the three bits is the time period for 60 cycle AC. This strikes me as a reasonable design because an adapter or other electrical appliance (TV in the car) has time to recover from one voltage before it sees the next.

In terms of output, I tried the following:
1. 2611-410 adapter (1998): There is a 1/2 volt spike positive and negative a few nanoseconds wide and occuring every 20 microseconds or so. This is just high frequency noise from the switching power supply. The interesting point is that the noise occurs whether the adapter is plugged into house AC (essentially perfect sine wave) or inverter (stepped square wave).

2. The standard 72 watt brick that comes with most ThinkPads today: There are no pulses on the output and it doesn't matter what input source.

Now that I bothered to look, it strikes me that it was probably important to get rid of the spikes in older equipment so as not to interfere with modern lower voltage, lower current and higher frequency laptops.

I never had a problem using a DC -> AC inverter and I gave my reasons why earlier. Now I am quite comfortable with my setup, but don't use it if it fusses you.
... JD Hurst

[Leon]

Thanks once again to the J Team .

[krosenstein]

Speaking of car adapters . . .

Does anyone have any experience with the Targus Universal Adapter PAPWR300U? It looks like it's smaller and lighter than the IBM brick.

[kev009]

Many thanks for the clarifications. I used an IBM DC-DC power adapter for my 760xl and never had any hitches with it. I will go ahead and save some money with the inverter method. Would an inline notebook surge supressor be a good idea?

[Leon]

won't hurt, but IMO not necessary.....

[JaneL]

>Does anyone have any experience with the Targus Universal Adapter PAPWR300U? It looks like it's smaller and lighter than the IBM brick.
>

I used to have an earlier version of it. It was smaller and lighter than the IBM AC adapter, and you could heat a small room with it.