The Demonstration Dynamo includes 2-pole armature wound with enamelled copper wire and a permanent magnetic field provided by a removable magnet. The construction of the model is completely open and all components are readily observable. This model is mounted on a 200 x 125mm baseplate which also carries a hand-drive pulley 125 diameter coupled to the smaller dynamo pulley by a rubber belt. Electrical output is via a pair of 4mm sockets and a light emitting diode is provided as simple output indicator.The model may also be used as a motor on a 6 to 9V d.c. supply.Overall height: 180mm.