AUTOMATIC UNIT TO CONTROL BOTH PROGRAMMING DISSOLVE SLIDE-SOUND AND DISSOLVE SLIDE PRESENTATION

摘要

A projector control system normally comprises automatic slide projectors, a dissolver unit, a cassette recorder unit, and a remote control unit. The cassette recorder unit has two tracks, one for the audio, and the other for the sync. signals. Such projector control system can be used to control manually through a control switch of a dissolver unit either the programmation of sync. signals accompanying an audio-track which would have been preniously recorded for dissolve slide-sound presentation or it can also be used to control manually the operation of dissolve slide presentation only. This last operation can also be performed manually through a remote control unit. In this invention, an automatic unit is used with the projector control system to control automatically all operations desired. For instance, the programmation of the sync. signals of the dissolve slidesound presentation can be controlled automatically by means of the automatic unit. This is achieved by connecting the automatic unit to the manual control switch of the dissolver unit. The dissolve slide presentation without sound can also be controlled automatically in the same manner. The automatic unit can also be connected directly to the remote control switch in order to control automatically in the same manner the projector control system. The automatic unit consists essentially of an IC timer type 555 which produces an electical pulse of a duration corresponding to a desired time interval; a general purpose operational amplifier type 741 which reverses the electrical pulse to give an instant electrical pulse at every desired time interval, and a miniature SPDT relay which controls automatically all operations of the projector control system.