Tdk lambda 200 432w single output variable dc power supplies switched mode bench tdk lambda z20 20 the tdk lambda z20 20 400w single output variable dc power supply switched mode bench is a z device that impresses with rich features in a compact design which sets new standards with a size of just 70 x 83mm w x h the power supply provides two large displays and separate encoders for voltage and current along with extensive features on the rear side there is an integrated rs232rs485