A/C adapter question

[Mossen]

Hi,
This is more of a general electronics question rather than specific to robots, but I was wondering:

When you see an A/C adapter and it says "output: 3.6V-7.2V" what does that mean? Can the output voltage be adjusted somehow? How does it work?

This is what I'm referring to:
http://www.servocity.com/html/3_6-7_2v_nicad___nimh_peak_cha.html

[rbtying]

It means that the charger will charge batteries with varying cell counts, from 3 cell ( 3cell * 1.2 V/cell=3.6V) to 6 cell (6 * 1.2 = 7.2V).  It will automatically adjust to your battery, usually.

[Soeren]

Hi,

This is what I'm referring to:
http://www.servocity.com/html/3_6-7_2v_nicad___nimh_peak_cha.html

That's not an AC adapter, it's a charger (large difference, although they look fairly alike).

[z.s.tar.gz]

Yep. Although it contains the circuitry of an AC adapter you can't use it as a dc power source because there's a battery charging circuit standing between you and that raw energy.