On Thursday, 31 January 2019 18:41:05 UTC, Rod Speed wrote:
"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.

Which is why the AC current is pretty irrelivant.
When was the last time you saw a circuit or device that stated the capacitance and AC current ?