Multimeter MOD

[Sceadwian]

If the 12 volt supply you're using is a PC power supply you don't have to worry about it, the 12 volts it puts out is pretty stifly regulated, so even though you're within a half a volt of the dropout voltage you shouldn't have any trouble. If it's a 12 volt wall wart I would recommend testing the wall wart under the expected load and measuring the output voltage. A 12 volt wallwart rated for a much higher current than what you need would help as under the light load it will still probably be over 12 volts. Most wall warts are rated for their output voltage AT their designed current output, I've measured the kind of variation you're talking about before and I won't ever use a wall wart without checking it first to find out what the true output is under load. It's a trivial thing to do.

Oh, one more thing, good mod idea =) and don't be cheap on the filter caps you use on the regulator, use the recommend value on the input, and use more than the recommend on the output.