A fully charged lithium polymer battery has
a voltage of 4.2V. It must not be discharged below 3.0V.
The smallest available fun DLGs, like this, can have a flight weight down to 80g, including the complete RC equipment and battery.
Spring 2008 I exchanged my complete 35MHz equipment with 2.4GHz components.
Too bad if your brand new Futaba 2.4GHz receiver is specified down to only 4.0V...
Having 2 cells (~20g) in a plane which weights 99g (managed to keep this below 3 digits ;-) is not an option.
It will pump up the voltage from as low as 2.0V up to 4.5V. I did not choose a target voltage of 5.0V because the
servos otherwise would consume more current than needed for safe flying...
The circuit is designed around a LTC3402, a 2A, 3MHz boost converter.
NOTE: Be sure to apply the wire-wrap!
Note, 6/2009:I recently upgraded to the innovative Jeti Duplex 2.4GHz technology.
Fortunately they have a transmitter module which directly fits into my T10 (FF10, in Europe):
While the small Futaba R6004FF 4ch receiver has a range of only 300m (others of their line like R617 have
full diversity and full 2000m range but a weight of 9g) the new Jeti R5 5ch offers full range and diversity
at less than 5g and a smaller package.
Guess what project will follow soon? 8-)
Note, 8/2009:Others may prefer ACT. But, somehow their webpages hide most of the information...
They even were unsure about the size and weight of their receivers ;-)