Automotive Crank
  • Detail of Automotive Crank
    Detail of Automotive Crank

The Automotive Crank demonstrates how mechanical crankingwork can be transformed into electrical energy and stored in a capacitor to operate a flash lamp or incandescent lamps. Alternating current generated by the bicycle lamp generator is stepped up by a transformer and rectified to produce direct current to charge the capacitor (gray box, lower left, labeled "H.E.Edgerton"). The torque and number of turns can be estimated to compute work done.


Crank until voltage reaches ~400V and lamp flashes, producing intense light for a few microseconds. Crank again to a lower voltage and then hold down red button to flash incandescent lamps to produce weaker light for about a second.