Thinkpads Forum

Hi folks

I'm having some trouble here. I currently have a DC-DC converter, one of these thingies:



It's a great little thing. Unfortunatly it does not come with the right jack needed for a T61 (actually the same as a Lenovo 3000 N100 which i currently have). It seems that ever since a while ago Lenovo's machines have been using the 90W brick with a weird tip, with a positive central pin.
I'm sure y'all know what I'm going on about, as I can't seem to find a detailed picture of the plug in itself.

Would anyone know where to find one of these little thingies? I've searched loads of electronic suppliers in both France and Portugal in vain. I'd be happy to custom build my own power plug so i could use it with the travel converter i already have, rather than buying the bulky, expensive AC-DC and DC-DC combo adapter


Thanks for any help.

Moderator edit: Added PIC to subject line

From your description the plug may be type EIAJ-05. There are many different sizes of power plugs as noted here: http://en.wikipedia.org/wiki/Coaxial_DC ... Connectors

By measuring the plug that fits the Thinkpad, you can identify the plug type and might have better luck finding one.

BillP wrote:From your description the plug may be type EIAJ-05.

No. Wrong size and it only has a 2 Amp maximum current rating!

The measured outside diameter of the plug barrel on the ThinkPad 20 Volt power supplies in 7.8mm and the internal diameter is 5.6mm.

IGo has suitable tip for their power adapters, its their S31

Cheers,

Bill B.

Right. Found a nice pic:

http://content.laptopbroker.com/b80028f.jpg

It seems you're right Bill, thanks for that. This website says it's actually a 7.9mm barrel connector with positive center pin:

http://www.laptopbroker.com/product/ind ... ock=100270

It's getting late for me now, tomorrow i'll do some more research.

PS: thanks to the mod for the PIC mention editing. I didn't now that was requested, sorry

Does anyone know why the hell they switched the ac adapter to this format? Moving from a T42 to a T61 and now I need to repurchase all my spare adapters (don't like carrying them around with me). 3 old adapters laying around unused now... seems like there was no reason to switch.

Good explanation here
http://www.lenovoblogs.com/designmatters/?p=23

sveintore wrote:Good explanation here
http://www.lenovoblogs.com/designmatters/?p=23

Yup, and you can see my comment at the end of that same page...

I don't think they *really* explain why they switched... not a significant technical explanation as far as I can see...

There's another article here too, but with no significant explanation either...
http://www.lenovoblogs.com/insidethebox/?p=51

Anyway, any more info on the plugs would be quite welcome!

kamaleon wrote:I don't think they *really* explain why they switched... not a significant technical explanation as far as I can see...

quoted from the article...

"There comes a certain point where a change in voltage is the only efficient way to squeeze more and more from a power supply. Unfortunately, voltage changes require different circuitry, which in turn requires use of a different power supply."

"The new power connector will not physically fit in the power jack on an older generation ThinkPad. This was purposefully done to prohibit use of the wrong voltage in the wrong notebook; which, to drastically oversimplify, is not a good thing."

i'd say it's pretty clear why the changes were made.   newer and faster components need more power.   16V wouldn't cut it so a 20V supply was created.   the plugs were changed to prevent the old adapters with insufficient power to be used on the new thinkpads.

kamaleon wrote:Right. Found a nice pic:

img]http://content.laptopbroker.com/b80028f.jpg[/img]

It seems you're right Bill, thanks for that. This website says it's actually a 7.9mm barrel connector with positive center pin:

http://www.laptopbroker.com/product/ind ... ock=100270

It's getting late for me now, tomorrow i'll do some more research.

PS: thanks to the mod for the PIC mention editing. I didn't now that was requested, sorry

Is the adaptor different for the T61 than my T60? That picture looks like what I have. I got an extra when I bought my machine almost a year ago and bought a third rather cheaply off an ebay seller in Asia. It was a bit on the heavy side but actually uses even less power when left plugged into the wall, so I do like it all in all. The seller evidently specializes in AC adapters. I think the ebay username of the seller is it-sz, and I paid $24.99 including shipping from Asia.

Note from Moderator: Now, see, this is just one more reason I dislike in-line images. Some people are too lazy or careless to edit them out of their quotes.

erik wrote:i'd say it's pretty clear why the changes were made. newer and faster components need more power. 16V wouldn't cut it so a 20V supply was created. the plugs were changed to prevent the old adapters with insufficient power to be used on the new thinkpads.

Hi Erik, yes, I understand that, but I'm very sorry I don't think that's a logical explanation. Actually, I think that's not true at all!

Let me explain:

The latest trend in computer development is efficiency. We all know that one of the biggest effort being done nowadays, especially in the laptop domain (but not exclusively!) is to make things more powerful without needing more watts! Core 2 duos are not more powerhogs than the previous generation of components!

I currently use a lenovo 3000 N100, 1.66Ghz yonah, geforce 7300, hitachi 7K100, with the new power plug, my girlfriend has a Celeron 2.4Ghz thinkpad R40e (it's not even a Celeron M!), both our laptops consume the same amount of power - moreless. It's been a while I haven't taken any mesurements with my wattmeter though.

Plus, another thing, my 90W 20v power brick is bigger and bulkier than the previous 72w 16v! They say that the aim of boosting up the voltage is to make things smaller and more compact...

Come on, how can Lenovo say that their laptops are going to need more and more power? Do you think they're trying to say: "Hey fellas next generation thinkpads will only be able to keep for less than 1h on its battery!"

Muse wrote:Is the adaptor different for the T61 than my T60?

No, it's the same.
It is slightly different than my Lenovo 300 N100 though, mine has the same plug, same specs, but it uses a thicker AC cable with an earth connection (european model).

kamaleon wrote:The latest trend in computer development is efficiency. We all know that one of the biggest effort being done nowadays, especially in the laptop domain (but not exclusively!) is to make things more powerful without needing more watts! Core 2 duos are not more powerhogs than the previous generation of components!

even if newer processors are more efficient, besides having faster discreet GPUs we also have a trend toward more add-ons like wifi, wlan, bluetooth, wusb, turbo memory, and so on.   all of these require a specific amount of power no matter how efficient they may be.

kamaleon wrote:Come on, how can Lenovo say that their laptops are going to need more and more power? Do you think they're trying to say: "Hey fellas next generation thinkpads will only be able to keep for less than 1h on its battery!"

no, but i guarantee that battery technology will have to improve to keep up with system power and off-AC time requirements.   speed and power are not mutually exclusive.

kamaleon wrote:The latest trend in computer development is efficiency.

The constant trend in marketing is features. More features = more power, no matter which way you cut it.

kamaleon wrote:We all know that one of the biggest effort being done nowadays, especially in the laptop domain (but not exclusively!) is to make things more powerful without needing more watts! Core 2 duos are not more powerhogs than the previous generation of components!

Well all know that laptop users want more graphics capability, more wireless connectivity, more option slots, more USB ports, more memory, longer battery duration together with smarter charging.... all of which use power.

kamaleon wrote:Plus, another thing, my 90W 20v power brick is bigger and bulkier than the previous 72w 16v!

Compare it to the previous ~90W 16V packs and it IS smaller and more compact

kamaleon wrote:not a significant technical explanation as far as I can see...

That begs the question as to what you would regard as a significant technical explanation then?

I'm very sorry, this makes no sense...

Batteries might evolve in the future, yes, but for the time being they're still the very same than the ones from preceding generations of carmels, and banias, and dothans, etc, etc.

Discrete graphics are a feature that people seek, yes, obviously. Constructors try to reduce their thermal dissipation by miniaturizing their components, what are geforce 8 nowadays? 65nm? 45nm?

Santa Rosa laptops do not consume more power, on the average, than the preceeding generations!

Listen folks, my initial thread was not meant to discuss this, anyway. I appreciate the exchange of information, but i really have no personal interest in discussing this... without wanting to be unpolite. I really appreciate this board, I love the vibe around it and i find it really welcoming, and i learn a lot around here. But I'm afraid I'm not with you on this one

From my personal experience, my laptop (which is not even a santa rosa) consumes not more, not less than my girlfriend's thinkpad which still uses the 16v brick. Thus, I see no reason why my specific laptop should use the new one.

Does anyone know the exact name / reference or brand of this plug? I'm trying to find one in farnell.com

TIA!

The right thing to do would have been to come up with a new plug, but to also provide an adapter (or 2nd jack, but adapter is fine) to plug in the old 16.6v power supply.

The new thinkpad could easily have said, "Ah, I see only 16 volts." Then, if it saw that the battery was highly discharged, it could either have reduced charging current to it, or announced to the user "Sorry, we can't charge an empty battery and run your computer at the same time. Thus your battery is currently not being charged. If you wish to charge the battery, you may turn off the computer until the battery charge light blinks yellow, and then you can operate again. Or operate without charging as long as you like."

Note that the charging light blinking yellow would happen at something like 50%, essentially as soon as the charge current has dropped to a level the old 70 watt supply can handle while running the computer.

Other options would have included shutting off USB power, or limiting screen brightness or keeping the CPU at a lower speed or whatever else might keep the power budget in line.

Truth is, we are long past the point that power supplies and devices should be smart, and communicate about power needs, so that you only need one type of power supply to run just about anything. Laptops should plug directly into the smart plugs of the sort found in Kensington/Targus/iGo, though of course those are not standardized themselves. If Lenovo had chosen one, the world would have standardized very quickly.

But in this case, the laptop could easily know -- 16 volts means old supply, 20v means new.

Of course, old laptops could not physically plug into the 20v supply presuming they can't handle it, because the adapter would only work one way.

Modern devices all use cheap buck converter chips that actually take a wide range of voltages and convert to what's needed. I would be amazed if the TP doesn't do this, though I admit I don't want to try putting 20v into my older model to see what it does.
But any modern laptop could be set to easily run on anything from 12 volts to 36 volts with today's chips. (12v is pushing it a bit with a 10.8 volt battery, though it is such a worthwhile ability that having both buck and boost should be considered.)

The only question would be current. You want to know how much current the supply can handle. In many cases you can "test" it by drawing more current until the supply shuts down, but sometimes that would be because it blew a fuse or melted, which would not be good.

I found that when I ran my 4.5A thinkpads off older 3.5amp supplies, they worked fine except with a totally empty battery. In that case the supply would shut down due to the overcurrent and the thinkpad would beep, and so I would know to put it to sleep for a while. And that's without any planning for this contingency.

I wrote this up in more detail here:
http://ideas.4brad.com/laptops-could-ge ... ays-stupid

I think what you're looking for is the part number 41R4344 (Lenovo 20V Tip for ThinkPad R60, T60, X60, X60 Tablet, Z60 Series and Lenovo C, N, V Series).

Found it in the description of the ThinkPad and Lenovo 90W Slim AC/DC Combo Adapter (not as bulky as the old one. You might want to take a look).

You'll probably have to order it online. I'm not seeing regular Portuguese/French stores carrying it.

As discussed in another thread, I think that's a special TIP for lenovo's own universal power supply. Ie. one of those magic tips with extra pins that tells the power supply what voltage to provide.

What we are seeking is just the plain old tip, with solder lugs or a pigtail on it.

I am going down the same path here, only now its October 2008, so i was wondering if anyone found a source to buy a new plug/tip so that I can use my old universal adapters (set to 20 volts, of course) with my T61.
Thanks.