Abstract: A method of detecting an operating condition of a controllable flow regulator in a fluid flow channel of an HVAC system, comprising transmitting a sonic signal, from a sonic transmitter, directly or indirectly to the flow regulator, the sonic signal being distinguished from background noise by being at least one of: (i) modulated according to a modulation schema, (ii) an ultrasonic signal, (iii) a frequency selected to be away from background noise, receiving a signal from a sonic receiver for detecting the transmitted signal after interacting with the flow regulator; and determining, in an electronic signal processor, the operating condition of the flow regulator on the basis of the signal received.

Abstract: There is disclosed an evaluating circuit for use with a photoelectric transducer and an electronic photometer. The photometer comprises indicators, all of which are variable, and comprises a combining device arranged to combine by an inverse computing operation.

Abstract: A method and apparatus for the resynchronization of the transport of movie film (image carrier) with the movement of another information-carrying medium such as sound tape film. Speed control and synchronization signals are produced by means of sensing the sound tape movement which provides control synchronization signal, monitoring the image frames for each sequence on the movie film by means of a counter, and comparing in a coincidence circuit the image frame count signal with the signal from the sound tape. Desynchronization of the movie film and tape is indicated by the absence of a predetermined relationship between the number of image frames in a given sequence and the signal from the sound tape, whereupon the coincidence circuit energizes an appropriate control means via a switching mechanism, such as a gate circuit, which produces a resynchronization of the film and the sound tape.

Abstract: A cinematographic apparatus having an electric motor coupled to a drive shutter, first means coupled to the shutter for sensing a predetermined position thereof, second means coupled to the motor for locking said motor and the shutter in a predetermined position, and a control circuit for providing driving power to the motor, and third means for removing forward driving power, and control means including a trigger switch for unlocking said second means before actuating the control circuit to provide forward driving power to the motor; said control circuit is adapted to continue to supply forward driving power to the motor after release of the trigger switch, said third means removing forward driving power in response to release of said trigger switch and detection by said first means of said predetermined motor position, and said control means adapted to control said second means to lock said drive motor in a predetermined position after removal of the driving power by said third means.