
3 7 c m
40cm
actual image size: 32cm x 29cm
Description
Dumont cathode ray oscilloscope Type 208, serial number 3905. Seeing the waves made by oscillators was difficult until German scientist Ferdinand Braun (1850-1918) invented a form of cathode ray oscilloscope in 1897. An internal oscillator repeatedly sweeps a beam of electrons acros the screen at constant speed. The input voltage moves the beam up and down, drawing a picture of the wave. Modern oscilloscopes often display the picture digitally.
Image Details
Image Ref.
10251001
© Science Museum / Science & Society Picture Library