Controller for two audio visual projectors - uses CPU to control projectors from program on magnetic tape using serial digital data and D=A converters providing light intensity signals

摘要

The system operates with two projectors (3a,b) to provide an audio visual programme, such that as one is illuminated the other is extinguished. The system has a control desk (1) on which are mounted push buttons (7a,b) which are connected to a central processing unit (UCT) to control the projectors (3a,b). A rheostat (8) controls the light intensity for the projectors via an A/D converter (11) coupled to the processing unit (UCT). A D/A converter (12) applies the intensity signals to an interface (13) for the projectors. An oscillator (16) provides a clock frequency for the processing unit which contains a microprocessor. Cassette recorders (19,21) provide control signals for the processing unit to obtain the required programme of events.