The 1901B is a laboratory-grade switching DC power supply designed for high-current applications requiring flexible voltage and current configurations. It features a variable output voltage range of 1–32 V and variable output current of 0–30 A, delivering a maximum output power of 960 W with high efficiency (87% at 110 VAC, 86% at 230 VAC). The supply incorporates automatic constant voltage (CV) and constant current (CC) crossover operation, rotary encoder control knobs for precise settings, and supports up to three user-defined voltage and current presets for quick recall. Additional capabilities include analog remote control, USB interface connectivity, and comprehensive protection circuitry (overvoltage, overtemperature, and overload protection). The 1901B is well-suited for production testing, telecommunications, research and development, service applications, and university laboratory environments where reliable high-current power delivery is essential.