Hi, can i use and AC/DC Adapter that gives a 12V and 5A output to power the lynxmotion adapter board instead of the 3S Lipo battery ?
Do you mean the RB-Hap-05 (12 V DC, 6 A)?
If so, then yes, you can use this with the Lynxmotion Adapter Board [RB-Lyn-1018]. They are meant to work together with the LSS 4DoF robotic arm [assembled, not assembled] and the new 3 DoF robotic arm [RB-Lyn-1061] but that power supply can certainly be used with other combinations of LSS and adapter board.
Let me know if you have more questions.