GB1332176A - Lighting control apparatus - Google Patents

Abstract

1332176 Lighting control DYNAMIC TECHNOLOGY Ltd 23 Nov 1971 [7 Sept 1970] 42835/70 Heading G4H Lighting control apparatus for controlling the brightness of a group of lamps comprises a main store 10 for storing lighting "plots" containing brightness control information for each lamp in the group, one or more operation a stores 12, means for transferringal lighting plot between the main store 10 and an operational store 12, means for controlling the brightness of a lamp in accordance with the control information stored in that operational store, and means 16, 18 for changing the information relating to an individual lamp in that store. As shown, 128 plots of 256 lamps are stored in main store 10, a particular plot being addressed by means of a decimal key control console 46, and a 5-bit binary code indicating one of 32 brightness levels for each lamp. The plot in use is in store A, Fig. 2 and the next plot required is in store B. To "fade" from A to B, the outputs therefrom are fed to analogue, digital or hybrid multipliers 20, 22 to be multiplied by (1-Z) and Z respectively and then to an adder to yield an output (1-Z)A + ZB which is fed in digital form to a sample and hold circuit 48 (here an array of capacitors) which stores brightness control information for staticized control of the lamp dimmers. The multiplication factor Z is controlledly varied from 0 to 1, and is determined by integrators 24, 26 according as A#B or directly from a set of input levers (not shown). Each of the 256 lamps in a stored plot is sampled in turn by binary decoders 44, 45, 52, Fig. 3 fed from a binary counter 56 driven by an oscillator 54. The information in a store relating to an individual lamp is changed by means of a control 16 (digital shaft encoder or manually operated lever) and is gated into the scanning cycle by a pulse which is delayed by an amount corresponding to the position of the lamp in the cycle: a decimal counter 50 feeds hundreds, tens and units pulses to a circuit (Fig. 5) which generates corresponding partial time delays determined by the setting of a lamp selector on the control console. The selection of a lamp for individual control allows the original brightness thereof to be displayed for reference, e.g. by means of a displacement over a calibrated scale of the above-mentioned manually operated lever. The brightness information contained in stores A, B can be displayed on the control console by means of an array of differently coloured pairs of bulbs. An indication of which lamps are switched on (together with brightness indication) in a store may be produced by means of a CRT, and a colour CRT may be used to provide differently coloured displays for different stores; in these cases the CRT could be used with an array of photo-cells or a joy-stick control to effect individual lamp selection. It is possible to utilize only one store 12 (Fig. 1 not shown) or to use more than one pair of stores A, B in which case the outputs from each adder are combined by a "higher brightness level takes precedence" method for each lamp.