"whisky-dave" wrote in message
...
On Thursday, 31 January 2019 18:55:32 UTC, Rod Speed wrote:
"whisky-dave" wrote in message
...
On Thursday, 31 January 2019 11:44:36 UTC, Martin Brown wrote:
On 30/01/2019 13:39, whisky-dave wrote:
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 ?

Did they not teach you the impedance of a capacitor then?

Well yes but it's really Reactance you're refering to isn't it.

And we donlt in the UK for wall marts use capacitors to drop the
voltage.

Wrong, as always.

tell you what take one aprt and show me
these capacitors used to drop voltage.

Big Clive has done that, mostly with chargers.

The "low voltage" output can find itself at mains potential if the
wrong
capacitor fails open circuit. Killed some Apple user in the bath.

https://www.telegraph.co.uk/news/201...g-iphone-bath/

I actually fail to see how he was killed by a genuine Apple charging
device - all the ones I have seen were properly engineered.

Not a very good report is it.
It shows the headphone to lightning adapter as the charger ?
It also says that the charger was in the bath which is a differnt
type of accident, and what;'s this extention cord they are refering to
?

"We found an iPhone plugged into the extension cable
and then the charger element in the bath," he explained."

The forst enalrger timer I built from a magazine
used a 10W 33K dropper resistor to power a 555.

And a capacitor works much better.

No it doesn't if it did we'd be using them for such things, we don't.

Done quite a bit with internal power supplys for lower power devices.