A stimulating addition to any lesson on energy conversion electricity or magnetism.For demonstrating the variation of electrical output of a dynamo with its rate of rotation and the way in which the electrical load connected to it affects the amount of work required to drive it. The double stage step-up gear system gives an overall ratio of approximately 1:25.The hand generator directly involves the students in investigations by using their own energy to generate d.c. electricity. Slowly turn the handle and any 6V bulbs attached will light dimly turn faster and the bulbs become brighter. The d.c. hand motor/generator is a high quality motor unit driven from the hand crank via 2 stage step up gearing. It is capable of generating approximately 6V d.c. with the polarity determined by the direction the handle is turned.Supplied with 1m of detachable twin lead terminating in a pair of crocodile clips.Dimensions: 200 x 100 x 85mm. Weight 275g.Attaching a 6V MES bulb in a holder using the 4mm sockets on the generator will show that a lamp increases in brightness when the generator is operated at different speeds.