Aim tti twin 420w powerflex max 60v or 20a usb rs232 lan cpx400dp aim tti cpx400dp p the aim tti twin cpx400dp is a different type of laboratory power supply designed to meet the need for flexibility in the choice of voltage and current a conventional psu has a fixed current limit giving a power capability that reduces directly with the output voltage the aim tti twin cpx400dp design enables higher currents to be generated at lower voltages within an overall power limit envelop