Targus Mobile 70 Universal AC/DC Adapter?

[jsmit86]

I have recently purchased a Targus Mobile 70 Universal AC/DC Adapter.

I have discovered that if one tries to use the adapter with a T42, the adapter will not charge or power the notebook unless the power is already on.
If you try to use it with the PC off to charge the unit, the pc BATT LED just flashes. If you disconnect the battery, you cannot power on the PC.

If you insert the tip while the pc is on and running on batt power, the adapter seems to function normally. I did some searches on another forum, and found the same issue listed with the IGO Juice when used with a Toshiba Tecra PC.

I think the IGO, Targus, and Kensington AC/DC adapters are actually the same OEM unit.

Do any other users have any experience with this?

[jsmit86]

Anyone?

[jsmit86]

I am posting this because I have a bit more information, and even though my problem is not yet solved, the additional information my help me solve this issue, or another forum member avoid a problem.

I got an update today from Targus. Their customer service emailed me and said that they did not have an approved tip for the T42. This is despite the fact that the website lists IBM T series as compatible with tip #4A.

While I was in the office today, I tried the Targus with an IBM T23 and it worked fine!

I would like to know if any other T40 41, or 42 users have had any success with these universal adapters.

[jsmit86]

I recently received the Kensington Model number: 33173 AC/DC Adapter.
While it seems to be almost identical to the Targus unit, It works fine.

All of the Tips, cords etc are interchangable between the 2.
I tested it various ways, and the problem component appears to be the Targus "Brick" unit.

So in summary, the Kensington unit works fine.

[jsmit86]

While the Kensington unit did seem to work at first, it also developed the same symptoms. I ended up getting the IBM AC/DC unit, but I still have the Targus and the Kensington. If anyone has any updates on IGO/Targus/Kensington compatibility with T42, please post.

[w0qj]

i also just got the IBM AC/DC Travel Adapter, thanks to everyone's valuable suggestions/experience in this forum!

but the adapter is BIG and HEAVY... almost twice in size (by volume), and much heavier... not exactly portable, i would say...

[lvlolvlo]

i also just got the IBM AC/DC Travel Adapter, thanks to everyone's valuable suggestions/experience in this forum!

but the adapter is BIG and HEAVY... almost twice in size (by volume), and much heavier... not exactly portable, i would say...

i just rec'd mine along with my recplacement battery and whoa momma it's big! but hey it works fine

[jsmit86]

It would be nice if Targus/Igo/Kensington would address the compatibility issue with the T42's. While their adapter is also a bit larger than the IBM AC only, it is smaller and lighter than the IBM AC/DC.

I put in a Tech Support email to Kensington on Monday to see if they plan to address the issue. I will post the response.

[jsmit86]

Pretty useless reply -
QUOTE from Kensington Tech support:

I apologize for the delay in response.

As of now IBm T42 is not listed in the compatibility chart so we do not have a compatible tip for this laptop. We may come out with a new tip however the information on compatible tip will be posted on website as soon as we have a new tip.

I would suggest you to check our website regularly to find out the information on availability of tip.

Thank you for contacting Kensington Technical Support.

[mikers456]

Here is how these bleedin' things work. Before you punt it...

The targus 70 and 90 brick adapters come with a box full of tips. The tips are the magic. Each tip, besides being a specific physical size, has the ability to communicate with the brick and tell it to output a specific voltage. The S3 tip will output a different voltage than the S4 tip. It probably is not a good idea to use a tip with a notebook it is not meant for (eg. S3 tip with the T42 is BAD, S4 tip with T42 is GOOD).

Testing out the various tips with the targus ac90u brick, I found that:
The voltage from the S4 tip is 17.0V DC (tip is +, barrel -)
The voltage from the S3 tip is 19.3V DC (tip is +, barrel -)

The tip itself is responsible for setting the voltage that the brick will output (it sets a reference that is read by the brick and reacted to to output the proper voltage). This is done with resistances in a very analog (not digital) manner. There are 4 wires running between the brick and the tip. 2 are for output to notebook, 2 are for the tip telling the brick what voltage to output.

This makes sense because if you look at the back of the targus, you find that its voltage range is 15-24 VDC, a little too... wide? So each tip fine-tunes the exact voltage. This allows targus to make one type of brick and multiple tips, each tip fine tuning the output parameters for the particular notebook it was designed for.

So when Targus tech support tells you there isn't a tip that will work with that notebook, they mean it. Using the wrong tip will put either the wrong voltage, or possibly wrong polarity to the notebook. Best case it works, or weird behaviour but no damage. Worst case it fries something or doesn't work at all (if notebook is well designed). Look on the website to see which tip is the correct one for the notebook you want to use it with.

And as for the amperage rating... Its more critical that the adapter isn't being loaded too heavily, as that will tend to affect the voltage downwards (as you draw more current towards the design limit of the adapter), or make it more unstable (or blow a picofuse, or melt or damage the adapter due to over-heating). If you need to use a lower current adapter with a higher current needing notebook, you can reduce the brightness of your screen, unplug any accessories, remove the CD/DVD drive, turning off the wireless card, unplug any PCMCIA cards, don't charge the battery and put the CPU into a slower speed/frequency (kindof like on battery mode). In that manner you COULD use a 3.3A adapter with a 4.5A notebook, by sheding load (for an extended period of time).

I believe that the three most power intensive things on the notebook, in order of current draw/power rating are: the battery charger, the processor and the wireless card.

[craigg]

I have an APC Auto/Air/Home universal adapter yet hardly use it because it is so heavy. I love the small size and light weight of the ThinkPad ultraportable 56W AC adapter that comes standard with the T43. When I am traveling I use a pocket inverter like one of these:

http://www.vectormfg.com/site2/vectormf ... cts_id=348

http://www.costco.com/Browse/Product.as ... =&cat=&s=1

On a plane if I need power I use one of these adapters with my pocket inverter:

http://www.buy.com/retail/product.asp?s ... c=101&sp=1

The combination works like a charm and is very light for travel. The added benefit with the small inverter is I can power / charge many small electronics such as my cell phone, bluetooth gps, etc...all with the same adapters and on top of that both parts can be had for less than $25 if you look around

[awolfe63]

I have the same adapter with my T42 - works fine.

[KrS14]

I had an AC90U and an S3 tip that i needed to hardwire into the laptop (User broke off the jack inside the laptop) So i did some cutting and measuring and came up with this info.

I know this thread is old, but it may be useful for someone.

2 pins on one side are for power and ground, the other 2 are for the sensing of how much voltage to put out.
Crude drawings to follow:

  ____  ____
 /      \/      \
|   .  .  .  .   |
 \_1_2_3_4_/
This is the cable end that connects to the brick, with corresponding pins 1-4. Looking at the cable end.

1.)Sense (Brown wire in cable)
2.)Sense (Blue wire in cable)
3.)Tip (+) (Thick red wire in cable)
4.)Barrel (Ground) (Bare sheath in cable)

Both Sense wires are connected through a resistor to ground (Pin 4 internally)
1.) is 71K Ohms
2.) is 5.47K Ohms

This sets the 19VDC the brick will output.
No idea what relationship the 2 sense wires have to eachother, just trying to post useful info