The BX15A Series PWM servo amplifiers from Advanced Motion Controls are designed to drive brushless DC motors at a switching frequency of 26 kHz √Ç¬± 15%. A single red/green LED indicates operating status. The amplifiers are protected against over-voltage, over-current, over-heating and short-circuits. Units interface with a digital controller or can be used as a stand-alone drive. The models require a single unregulated dc power supply. Loop gain, current limit, input gain and offset can be adjusted using 14-turn potentiometers.