Hello. I recently bought Graupner Ultra Trio Plus 14. I'm having trouble with understanding, how to connect charger to PC (personal computer). Charger have 3-pin connector. Pinout please... How do I connect this charger to PC? Is this possible without any adapter? Do I connect these three pins directly to RS232 port on PC? Pinout please... Or do I donnect these three pins to USB? Pinout please... Thanks for any pinouts / suggestions.