Aim tti power supply single 420w powerflex cpx400sa aim tti cpx400sa p the aim tti power supply single 420w powerflex cpx400sa is a different type of laboratory power supply designed to meet the need for flexibility in the choice of voltage and current p p a conventional psu has a fixed current limit giving a power capability that reduces directly with the output voltage p p the design of the aim tti powerflex cpx400sa enables higher currents to be generated at lower voltages within a