BK 1657 1500VA AC power supply. The 1657 is an AC power source that provides high conversion efficiency and low distortion output. It has a universal line output terminal and a built-in PFC to provide an input power factor of 0.99 at full load. The AC output provides up to 1500 VA and can operate in one of two voltage ranges, 135 V or 270 V, with 0.1 V resolution. The bright display constantly monitors the output voltage, current, power and frequency and also indicates the selected range and mode of operation. The front panel interface is easy-to-use and includes a control knob for quick setting of voltage and frequency parameters. The 1657 can also be controlled remotely via RS232 interface.