02-11-2017, 05:01 PM
Did you know that to run a Nipkow disc at 7500 rpm (Using 81 holes for 405 lines) you really need to run it at reduced air pressure otherwise the heat generated by friction of the disc spinning in the air can require the dissipation of as much as 500 watts! This can cause problems for the mechanical stability of an aluminium disc. By reducing the air pressure to 1 cm of mercury the heat dissipation reduces to about 30 watts.
This paper published in February 1939 in the Philips Technical Review discusses some of the problems and the techniques for manufacture. There is a number of papers in PTR throughout the 1930s on mechanical scanning as applied to film transmission.
Peter
This paper published in February 1939 in the Philips Technical Review discusses some of the problems and the techniques for manufacture. There is a number of papers in PTR throughout the 1930s on mechanical scanning as applied to film transmission.
Peter
