On Wed, Dec 15, 2010 at 12:47 PM, Michael Watterson wrot= e: > Wrong kind. > That's for running off 2 x AA or one LiPoly. For 5V and 1A that would > not be a good idea. > > You want the OTHER kind of switcher that reduces the voltage, always. > Using a higher voltage makes it easier to recharge from 12V or Car and > gives less losses generally as diode drops or IxI xR loss is lower. > Double input volts then nearly 1/2 current. 2 x AA or 2 X C input volts, > gives twice current, > > Regarding D cells. > In theory they exist, In practice very very expensive or really C cells > in a bigger box. > > AA 1800mAH to 2200mA 2500mAH Higher seem to be optimistic and self > discharge fast. > C 3000mAH to 3,500mAH. The 4000mAH seem to be related to 2700mAH > fantasy AA cells > > I use 18 x C NiMH to replace 19 x D NiCd and it's only slightly less > capacity than original. The NiMH seem to be slightly more volts. Hence > 18 rather than 19. It's for a 24V military man Pack. About 100mA to > 250mA on receive and about 3A to 5A peak on transmit. Yeah, I just ordered some samples of LTC3112. I ignored Linear Technology because last time I checked, they weren't giving out free samples. But I decided to check again and signed up with a university email address and placed an order. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .