As you see in the picture, the cord size at the input of the laptop adapter is bigger than the one at the output.
What is the reason for this? I guessed it is relating to current capacity but my friend said that is not the case.
He said that the current flowing through the output cord is also higher than the input one.
Is that wrong?

 

Input: 100-240 volts @ 1-0.5 amperes
Output: 16 volts @ 4.5 amperes.

Your friend is right.

 

So, what is the meaning of these parameters?

Input: 100-240 volts @ 1-0.5 amperes
Output: 16 volts @ 4.5 amperes.

I consider the adapter is a power supply so 16V is output voltage and 4.5A is current capacity of the source but how about 100-240 volts @ 1-0.5A?
Is it the current capacity of wall socket?
And the cord size?

 

You also have to consider electrical breakdown at the higher voltage,100-240VAC.

The input power cords are standardized items that must meet international safety standards. These are stock components that are supplied in huge quantities. The OEM (original equipment manufacturer) does not have much say in the matter.

 

So, the bigger cord is to avoid electrical breakdown. What are other reasons?

 

So, the bigger cord is to avoid electrical breakdown. What are other reasons?

-More durable.
-Can carry more current.
-More expansive.

 

Thanks, what do you mean by "more expansive"?

 

You will notice that the AC mains power cord can be unplugged from the adapter. That is so that the manufacturer of the computer equipment can supply the same adapter for international markets and all they have to change is the AC mains power cord to suit the local AC wall socket required.

 

The input cord must meet many safety criteria - including being stepped on or pulled from the walk by the cord (instead of the plug). All without catching your house on fire or exterminating the user! Safety, safety, safety! The copper adds most of the tensile strength of the cord assembly.

The risk of failure is too high to make 120/220 V power cords for fractional amp equipment out of copper of the minimum wire size for their amperage.

 

Also. The input cord is 3 wires. Output cord is only 2 wires.

 

Now that I zoom in, it looks like low-voltage output wire is 18 gauge (probably the same as the input mains voltage cord). Read the small white letters on the cord. It should tell you wire size and insulation voltage rating.

The mains voltage cable has thicker insulation to add to tensile strength and wear from abrasion, bending and compression.

 

The input cord is 3 wires.

I read and understood the concept for safety in the forum tutorial. However, here where I live doesn't use the third wire, mostly.

 

Now that I zoom in, it looks like low-voltage output wire is 18 gauge (probably the same as the input mains voltage cord). Read the small white letters on the cord. It should tell you wire size and insulation voltage rating.

The mains voltage cable has thicker insulation to add to tensile strength and wear from abrasion, bending and compression.

Actually, that is not my adapter. Mine is Dell one and it doesn't have any information on the wire. I will take a look at that adapter tomorrow.

 

Actually, that is not my adapter. Mine is Dell one and it doesn't have any information on the wire. I will take a look at that adapter tomorrow.

Sometimes it is hard to see, small letters/numbers impressed in the cord during molding (cladding) or other times it is printed. Look closely, it would be odd to have nothing on a cord - no matter where in the world it was to be sold. It just costs more to do things differently for each region when it could all be done the same way.

 

Yes, you are right. I just found out.

 

It should also be written on the length of the cord and repeated every 50 cm or so.

 

It is not clear now. I can only read something like this:
LFC-3R...KTL SUO1001-4002 227 IEC52 3G-0.75mm LONGWELL 2010

 

Yes your friend is right. You can also see on the adapter that the specifications of the Input and Output are mentioned at there. You can notice from there that the Output current is high than the Input Current.