SMPS used at 110v instead of 230v Question??

I have 4 mobile phones and chargers, all different manufacturers. (Sony, Siemens, Nokia, Motorola)

All apart from one (Sony Ericcsson) have labels stating 230v use only, one states 110v-240v.

All seem to be made by Astec of China

All 4 give an indication on the phone that enough voltage is being supplied to charge the phone when used at 110v, plugged into my bathroom

110v shaver socket.

Is it just a label thing, in fact are all these chargers capable of being used on 110v, in America, without the need to buy a specific 110v travel charger ?

As I understand it, they may be switched mode power supplies, the technology I know very little about.

Does it do any harm to operate these chargers on 110v, instead of the labelled 230v ?

How do I tell if it's switched mode from the outside, or if I open it up ? Thanks

Reply to
Charger
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Hi,

snipped-for-privacy@LightBrigade.invalid (Charger) wrote in news:1h0uonl.idypys1h5d2qlN% snipped-for-privacy@LightBrigade.invalid:

Quite strange! It seems as if they use a controller chip without UVL (undervoltage lockout) that stops operation when driven with too low a mains voltage.

Not sure about this, but a "normal" SMPS should not be operated at excessive undervoltage because it works agains low input voltage by drawing more current from the primary. When you use with it half the nominal mains it draws twice the nominal input current (roughly ...). And more current means more heat which is dangerous for most power components.

See above, it will probably not kill them immediately but they will in any case suffer from that! The mobile chargers are taken to the minimum cost point ... and cooling for the power components is one of the most expensive things in such small devices!

Just compare the weight and size to a standard wallwart power supply! SMPS do not use "heavy" metalcore transformers but small and lightweight ferrite transformer.

BTW: The one stating 110-240V is surely a SMPS!

Regards Michael

Reply to
Michael Bohlender

The charger doesn't get hot at 110v at all, no discernible temp rise at all

Reply to
Charger

If it's not specified, then the device isn't guaranteed - but if you've already tried it, it worked, and you didn't burn the house down, why are you asking? ;-P

Cheers! Rich

Reply to
Rich Grise

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