LM317T Voltage Regulator with Pass Transistor

Yes, you could just install the 3s lipo and run your x9303. However the voltage will be about 1.5 volts higher than the stock setup (fully charged) and you run the risk of over heating the internal voltage regulator and having the transmitter shut down unexpectantly. (wow would that suck!) To solve this problem, I copied what others have done, I installed two diodes in series with the battery. Each diode drops 0.7 volts, for a total battery voltage reduction of 1.4v. End result is a fully charge lipo @ 12.6 volts appears to the transmitter as as 11.2 volts. This is equivalent to a fully charged 8 cell NiMH battery at 1.4 volts per cell.



http://www.youtube.com/watch?v=O8jMk1O1Cug&hl=en