Keithley 2450 single output variable bench dc power supply keithley 2450 p the keithley 2450 is a single output variable bench dc power supply sourcemeter smu instrument that truly brings ohm s law current voltage and resistance testing right to your fingertips p p the innovative graphical user interface gui and advanced capacitive touchscreen technology allows intuitive usage and helps to minimise the learning curve to enable engineers and scientists to learn faster work smart