“Constant Current and Constant Potential Generators for Motion Picture Projection”
A. M. Candy · Transactions of the Society of Motion Picture Engineers · 1924
THE projectionist in the booth of a modern motion picture theatre usually has numerous duties to perform—among which the most important is that of maintaining a uniformly well lighted picture on the screen. This can only be accomplished and the effect on the screen will be an exact reproduction of the origina scene only if the light source in the lamp house operates at a constant value.