The Thyristor and Diode Trainer is a versatile teaching aid.It explores the principles and applications of thyristors, diodes andconverters. The control panel has clear mimic diagrams with shrouded sockets.Students use shrouded leads to connect the different parts of the circuits. Theparts include thyristors, diodes, inductors, transformers and smoothingcapacitors. A mix of standard analogue meters and a multifunction digital metermeasure the currents and voltages in the circuits. The multi-tappedtransformers give a choice of single and three-phase AC voltages for connectionto the diodes and thyristors. A centre-tapped inter phase transformer shows theeffect of reducing circulating currents in rectifier circuits. A load inductorshows the effect of inductance when smoothing the AC ripple in rectifiercircuits. Fast-blow fuses on the control panel protect the load side ofexperiment circuits. Students use controls on the lower panel to adjust ACsupply voltage and ballast resistance during experiments.