Foreword   This topic addresses the use of mains electricity with power supplies for analogue model railways. The subject is relatively specialised, but it does come up on the forums from time to time.   Most modellers begin their career with a self-contained, mains-powered model railway controller. These are the controllers supplied with train sets, and those manufactured by specialised manufactures such as Hornby and (in the UK) Gaugemaster. Some people know these units colloquially as ‘tr