Edgerton’s first commercial stroboscope, introduced in 1932, was a 50-lb monster. By 1935,he had designed a truly portable stroboscope, the Strobotac, that weighed a mere 10 lbs. This drawing is one of many showing the evolution of the Strobotac’s design (as well as the spelling of its name!).
Circuit diagram for Strobotac.