Wire me a plug!

wet-paint

Hey folks,
I bought a laptop in the states, and I cut the plug off of it to wire an Irish one on. Trouble is, there's only one coloured wire (green and blue) and two black ones. How do I find out which is the live and which is neutral?

*Kol*

The green is the earth anyway. The blacks are the live and neutral. Was one of the flat pins on the plug you chopped off wider than the other? If so that was the neutral pin.

You might be safer just to buy a new lead with the plug on it. Bring the transformer to a computer /electronics shop and they should sort you out.

wet-paint

Nope, both pins were identical, so no joy there.
And I checked the last time I lost the lead to my other laptop (identical make and lead) and it's a bitch to find a replacement lead, as the head is pretty unique.
I figure someone with a knowledge of physics or electronics would know?

AlmightyCushion

Moved from Laptops. Hopefully you can get an answer here, wet-paint.

2011

Before you do anything else please check if this device is designed to accept an input voltage of 230 volts at 50Hz. Because that is what we have here. In the US they have 110 volts at 60Hz!!

I suspect you will be ok, because the laptops generally use a switched mode power supply unit which can accept either, but check first!!

2011

How do I find out which is the live and which is neutral?

Although I would suspect (I would not be certain) that it will make no difference which way around you connect it,I would look carefully at the plug you cut off to figure out which wire connected to which pin.

Once you know that you can figure out which is live and which is neutral.

Laphroaig52

2011 wrote: »

Before you do anything else please check if this device is designed to accept an input voltage of 230 volts at 50Hz. Because that is what we have here. In the US they have 110 volts at 60Hz!!

I suspect you will be ok, because the laptops generally use a switched mode power supply unit which can accept either, but check first!!

Careful with the terminology! Whether the PSU is switched mode or not has nothing to do with the input voltage. Many PSUs in modern consumer electronics and IT equipment are switched mode but that doesn't mean that they will work in both the US and Europe.

Check the rating label for the acceptable voltage input. If it says '100 ~ 230' or similar it is autosensing and can be used pretty much anywhere. However if it just says '110 VAC' then it won't work in Europe.

As a general rule most portable products (notebooks, cameras, handheld games consoles etc.) are autosensing. If they weren't it would make foreign travel very difficult! On the other hand most stationary products (TV sets, DVD players etc) are not.

Always check the rating label rather than an Internet forum!

*Kol*

wet-paint wrote: »

Nope, both pins were identical, so no joy there.
And I checked the last time I lost the lead to my other laptop (identical make and lead) and it's a bitch to find a replacement lead, as the head is pretty unique.
I figure someone with a knowledge of physics or electronics would know?

If both pins are the same size then it's not polarised and it will work whichever way you connect the two black wires to live/neutral.

steifanc

i agree with kol .
you could of just tryied an adaptor, if the power supply carries the ce label on the back it will be ok to use .
as was said before the blacks across L/N ,
its strange there not black and white tho
anyhow you should be grand

2011

Whether the PSU is switched mode or not has nothing to do with the input voltage

However many switched mode power supplies that work over a range of input voltages and still giving the same output voltage!

Many PSUs in modern consumer electronics and IT equipment are switched mode but that doesn't mean that they will work in both the US and Europe.

Exactly my point. That is why I said:

Before you do anything else please check if this device is designed to accept an input voltage of 230 volts at 50Hz. Because that is what we have here. In the US they have 110 volts at 60Hz!!

Amalgam

Is it a clover head lead, they're quite common in laptops, usually sold for about 9 euro, with an Irish plug fitted for use.

I brought back a HP pavilion laptop and most are dual voltage now, all you need is a new lead from the transformer to the wall.

Here's mine:

Laphroaig52

2011 wrote: »

However many switched mode power supplies that work over a range of input voltages and still giving the same output voltage!

I'm not really sure what your point is there.

My concern was that in your original post you implied that switch mode power supplies were all autosensing and that is not true at all.....and could prove an expensive mistake.

While most portable devices are autosensing, not all are. A good example is the AC adapter supplied with the Nintendo DS. They are rated for their specific region only and either won't work or will be seriously damaged if used out of region. They are still Switch Mode power supplies though!

Switch mode power supply is not equal to autosensing....they are two completely different concepts.

2011

Flyer28, you are corect.

In my first post I start well by suggesting to check the input voltage rating "before doing anything else".

While most portable devices are autosensing, not all are

That is what I was trying to say.
But, reading back now I see that my second sentance is poorley worded and implies that all switched mode power supplies are autosensing (which as you say is incorrect), I was trying to convey that most are.

Sorry, my bad:(!