Instek GPS-3030DD 90W Single-Output Linear DC Power Supply with 0.39" Dual Digital LED screen, 30V DC, 3 Amp Linear power supply unit provides a constant source of DC voltage and current for powering and testing electronic devices in research and development, production, and laboratory applications One output provides an adjustable voltage of up to 30VDC or current up to 3 amp Potentiometers on front panel provide fine and coarse adjustment of voltage and current output Dual digital LED screens show voltage and current readings simultaneously and are readable in low light Continuous or dynamic internal load selection for applications such as pulsed current