>>>Why do you need 1A? That's an awful lot. At 100mA you might be able to
>>>use a cheap and small 1000uF part.
>>
>>C = I/(V*120) = 0.1/120 = 830 uF
>
>Yes, of course, it's 1/10, but I qualified it ("may") because the
>assumptions were just picked out of the air, and 1000uF is more available
>than the next closest standard value (820uF). Another gotcha is the ripple-
>current rating, which may force a larger capacitor than would otherwise be
>required.

If my calculation came out to a value like that I would use a 1000uF anyway,
due to component value tolerances often being quite wide (-50/+100% often
used to be quoted).

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