>> internal resistance will increase.
>>
>=20
> Yes sir. What size capacitor do you recommend?

I've found with IR transmitters that a 470uF / 6V low-leakage
makes a big difference as the batteries run out. As Sergey says,
Vdd will droop and spike without a reservoir cap. You should
be able to work out what capacity is need to smooth Vdd. For
an IR transmitter the demand is fairly-well spaced bursts, giving
the cap time to recover somewhat. You might find that your
circuit draws too much current to be supplied like that from the
cap, but it would still be helpful for bulk smoothing and preventing
glitches
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.