wrote in message
...
On Wednesday, 30 January 2019 13:39:43 UTC, whisky-dave wrote:
On Wednesday, 30 January 2019 04:16:40 UTC, Rod Speed wrote:
tabbypurr wrote in message
...
On Tuesday, 29 January 2019 17:09:04 UTC, Dave Plowman (News) wrote:
In article ,
R D S wrote:

And why do similar rated ones differ so much in bulk? Is this just
a
build quality issue?

Older ones will have a transformer. Newer ones a SMPS - smaller and
lighter.

All wallwarts use a transformer.

Not all of them do. Some of the lower
power ones just use a capacitor dropper.

How do they work then ?
How do you know what voltage they produce and how will it convert the AC
to DC.



SMPSes just use a smaller one.

Wrong, as always.

They mostly use smaller transformers and therefore lighter than the older
sytle linear ones.

they don't mostly use them, they always use them.

No they dont with the always. Have a look at some of Big Clive's teardowns
sometime.

It's how isolating SMPSUs work.

But isnt the only way wall warts are done.