An experiment with a stroboscope

Abstract

On page 543 of vol. III. of the "Dictionary of Applied Physics", an experimental arrangement is described where the stroboscope disc is illuminated by an intermittent light, using a neon-tube, an induction coil, and an electromagnetically controlled tuning-fork. The same experiment can be performed in the light of an ordinary neon filled 110-volt Osglim lamp to which current is supplied from an alternating-current lighting circuit. If the laboratory supply is of continuous current, then the arrangement can be considerably improved with the use of a rotary convertor the speed of which can be regulated so that the frequency of the intermittent light can be ascertained directly with a speedometer and stopwatch. As a demonstration experiment this arrangement is particularly convenient, since both the stroboscopic disc and the frequency of the source of light can be varied at will, and very interesting effects may be observed.