Features: Programmable with USB-B port, connected to a computer for remote or automated control. Supports USB, RS232, and RS485 interfaces. Please contact us if needed. Wide range voltage Adjustable and output stable DC power supply with two adjustment methods: high-precision knob and directional key. 3 sets of quick parameter storage keys: can preset the voltage and current values when the output is turned off, and can quickly call up the pre stored values of 1/2/3, making it convenient and flexible. It has four protection functions: overvoltage protection (OVP), overcurrent protection (OCP), over temperature protection (OTP), and overload protection (OPP). Front 5V2AUSB charging interface. One click output on/off, one click voltage and current stabilizing switch, automatic locking menu key to prevent incorrect operation. TFT color screen LCD 4-bit display, 360 ° full view view. The panel can simultaneously display the output status, output current, voltage, power, and display time, as well as the switch status of overvoltage protection (OVP)/overcurrent protection (OCP). Can support global voltage adjustment: 110V/220V. Specifications: Output voltage: 0-40V, output current: 0-20A Resolution: 10mV (≤ 0.1%+5 digits); 10mA(≤0.1%+10digits ) Ripple: ≤ 12mVrms, ≤ 18mArms Load/power regulation rate: ≤ 0.2% Vmax+5mV Working voltage: AC220V ± 10% 50Hz or AC110V ± 10% 60Hz Max voltage: 40.5V Max current: 20.1A OVP: 0-41V OCP: 0-20.5A output power: 0-300W Size: 230 * 80 * 150mm Weight: 1.68kg Packaging content: DC output power supply power cord Instruction manual Test line USB connection cable