BK 1688B 1-18V 20A switching bench power supply BK 1688B 1-18V 20A switching bench power supply. Dual 3-digit LED Display. Automatic CV/CC crossover operation. Rotary encoder control for precise voltage and current setting. Save up to 3 user-defined voltage and current presets for quick recall. PC software for remote control and external timed programming. Analog remote control function. USB interface. Front panel auxiliary output. Overvoltage, overtemperature, and overload protection.