Automatic control for commentary assisted slide projectors - having slide change signals on tape with controlled fade-in

摘要

The tape recorder is coupled to a control device which incorporates an electromechanical analogue converter which translates slide change signals, superimposed on the sound track, into control signals for the two slide projectors. These project alternate slides. The control module has preset fade-in control which determines the time taken for the fade-in of successive slides. The system is used in programmes with a spoken commentary which have unequal sequences for the separate slides, and allow the projectionist to adjust the programme for the best effect.