Hand-cranked DC generator powers 120 volt lamp.

Hand-cranked generator powers lamp. This hand-cranked DC generator is similar to the alternator in D+15+10, however the slip-rings are replaced by split-ring commutators, resulting in a sinusoidal DC output. A geared hand-driven crank causes the coil to rotate. The rotating coil cuts across the magnetic flux of the surrounding permanent magnets, inducing an emf. Depending on the speed that the generator is cranked, the AC voltage may be as high as 75 volts. When the key switch is pressed, the light bulb glows and the generator becomes very hard to crank.