Thinkpads Forum

My thinkpad T510 came with a 90W, 20V AC adapter with a 2-prong cord. For as long as I have owned laptops, it seems that 2-prong cords have been the standard more or less.

I've been looking to buy another AC adapter, so I can keep one in my office. When I look online (flea-bay, in particular) I see a fair number of 3-prong AC adapters, including some that claim to be original Lenovo adapters.

Did Lenovo start using 3-prong AC adapters for the T510 some time along the way? Does anyone have a list of all the FRUs for the T510 adapters? The adapter I have is model 42T4430, FRU 42T4431.

I am tempted to just buy a second AC adapter straight from Lenovo, but their website is such a mess right now I can't even find the adapter on there!

A little more poking around, and after I added "clicktale.net" to my ABP filter (as in, reject all everything from it) and the lenovo website eventually led me to:

http://shop.lenovo.com/SEUILibrary/cont ... 48E9&tab=1

Which I see is a three-prong adapter. It shows 20V 90W so apparently some time since I purchased my laptop they switched to three-prong. $59.99 is a bit steep in comparison to other sources for the same, though.

Part number for this guy is 40Y7659

Lenovo (and before that, IBM) have traditionally been using 2-prong adapters for US, Canada and Japan (maybe a few other regions) and 3-prong for most of the rest of the world (EMEA, etc.)

Other manufacturers just use 3-prong. It seems more common.

Not to mention a bit safer, actually.
It's nice when you don't feel static when touching the fingerprint reader, where you can ground yourself by touching a metal part of the chassis.

The funny thing is that I've got an old ThinkPad 600E (and also a T41 which still uses the same brick) that run on 3-pin plugs- maybe cost was the factor?
Though the 3-pin connectors are usually more sturdy and fit better in the plug than the 2-pin ones do.
They take more effort to pull out of the wall, but that's not a bad thing in my experience.

What is also weird to me is the fact that the larger power bricks (the 135 and 170W adapters) don't have this grounding. If anything you'd think that those ones would have the thickest wires and better grounding.

Here in Europe it is normal to use a 3 cable mains adapter. That is because we use 230V rather than 110V and it is standard to have an earth wire as well as a live and return.

I believe a similar system is used in most countries outside Europe.

We always wonder how you manage to boil water using 110 volts.

Two-prong adapters are just crap, pure and simple. It annoys me that US-based Thinkpads use them, because every time I buy a machine from there, I get one of these, and then I either have to live with small electric static shocks, or procure a normal adapter somewhere.

I used to really wonder why the heck they use these, since every socket I've seen in the US so far had a place for a grounding connector. But then I was told that in Japan, the two-hole sockets are still more common than three-hole ones. Maybe that's the reason.

I have read that for some computers, a grounded plug improves the function of the touchpad.

For travelling, a two prong plug is a major advantage because a small 2-prong adapter can suffice for Europe, Switzerland, USA and more but a three-prong requires carrying multiple or larger combo adapters. That is one of the reasons I like Lenovos.

wwcanoer wrote:I have read that for some computers, a grounded plug improves the function of the touchpad.

For travelling, a two prong plug is a major advantage because a small 2-prong adapter can suffice for Europe, Switzerland, USA

You have a single 2-prong plug that works with USA, Swiss and European sockets?

It isn't only Switzerland that has non-standard sockets. UK, Ireland, and Cyprus use a system that is different from everywhere else in Europe.

Not a single plug but a single adapter that is oval and about the size of the end of a USA two-prong plug. Very small and easy to carry.
Ex: http://www.laptoptravel.com/Product.asp ... catID=5163

The the diameter of the prongs of a Swiss 2-prong plug is slightly smaller than the standard western european plug but it still works fine. Works other places as well.

With a three-prong plug, one typically needs a specific adapter for that country and thus one ends up with a large configurable plug adapter or several of them.

http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets
http://en.wikipedia.org/wiki/File:Weltk ... rtypen.svg