So here's a tricky situation (or so I think). I have exactly 14.2 Volts from a pair of 7.1 Volt batteries in series. I would like to regulate that 14.2 Volts down to 12volts. The problem is that all the V.Reg IC's I've run across all require a 3volt drop which would mean 11.2 Volts instead of the required 12. This is a problem because a component downstream of this power setup REQUIRES 11.6 volts. If it gets anything less its highly likely to shut itself off. Aux info: I plan on pulling no more than 1A (~500mA avg) from these batteries at any one time. The batteries are 1200mAh so they have more than enough juice to do this, additionally because of this, I'm assuming that the associated voltage drop with their discharging wont go to low in the 20 to 40 minutes I need whole circuit to function. Anybody familar with this type of situation?
Either try to grab a "LDO" (low drop out) regulator, or you could just grab a cheap 12V reg and do some actual measurements, the actual voltage can be as low as 1V when it says 3V in the data sheet, 3V is the worst case scenario at full load, if you have a reg that can handle 3A and only load 1A, the dropout should be lower than the data sheet says.
Try www.digikey.com and search for "LDO voltage regulators". I found LD1585C with 1.4V max. dropout @ 5A. The adjustable ones often behave better than the fixed ones. I don't know why. The adjustment feature will also make it easier for you to get exactly 12V.
