The JET Power Supplies can be divided into two main groups e.g. the power supplies to feed all the coils for the tokamak and the power supplies for the heating systems on JET. Most of these power supplies are of a conventional design with classical thyristor rectifiers either in the starpoint configuration or as a three phase bridge at the output of the transformer. Over the last couple of years a few fast power supplies have been designed and installed using GTO's and IGBT's. The first power supply is the Disruption Feedback Amplifier System (DFAS) which will be used in experiments to investigate disruptions and how they can be stabilised. The second power supply is the Fast Radial Field Amplifier (FRFA) which replaces the old thyristor Radial Field Amplifier which is not fast enough to cope with the more demanding situations for the control of the vertical position of the plasma after the installation of the divertor coils. The third power supply is for the Glow Discharge Cleaning. This power supply was installed last year to provide more power to the new Glow Discharge Cleaning System used for cleaning the inner wall of the vessel. The paper gives an overview of these three power supplies. Preprint of a paper to be submitted for publication in the Proceedings of EP2 Forum 95 Electrical Power Cern, Geneva, Switzerland, 2nd March - 3rd March 1995