How come ac adapters getting smaller and lighter?

Question

What technology is being put in ac adapters (power transformers) such as mobile phone chargers to make them smaller and lighter. I remember the first charger of the first mobile phone I had was bulky and heavy but nowadays all adapters seem quite compact and rather light. Is there a shift in the technology being used or where the materials used changed?
Thanks

Answer 1

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there are several factors involved.

first, the charger must be good for world wide use
second, the cost must drop
third, a desire to make things cheaper
fourth, a desire to make things lighter.

The answer to all above caused a shift from traditional "linear type" to a "switching type".
Linear used heavy, copper wire, transformers that could not EASILY change input voltages for a desired output. Copper is expensive, copper is heavy, transformers are not energy efficient.

Switching supplies are lighter weight, cost less, and they do not care what the input voltage or line frequency is. They do have one nasty side effect, they are very NOISY. Environmental noise, interference generating noise, they are REQUIRED by FCC and CE rules to have noise suppression. That is what the bumps are on the power cords.

Answer 2

I'd also add that the power consumption of electronic equipment has gone down, so you can have a smaller, lighter charger/adaptor.

I've had several laptops, going back 15 years. The 1st charger was like a brick. My latest PC mains charger is slightly bigger than a 'candy' bar mobile 'phone. The cables are also thinner, as it uses less power.

Answer 3

Newer technology and more research being put into smaller technology.

People nowadays don't want to carry around big bulky things like chargers and phones. They want small items that fit easily into pockets and bags.

Smaller sells!

Answer 4

Different use of materials. New conductors, wires etc.