"whisky-dave" wrote in message
...
On Wednesday, 30 January 2019 19:37:07 UTC, Rod Speed wrote:
"whisky-dave" wrote in message
...
On Wednesday, 30 January 2019 04:16:40 UTC, Rod Speed wrote:
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 ?

The capacitance determines the AC current.

But most devices are voltage driver.

Thats why you rectify and regulate it after the cap, stupid.