Lighting control apparatus with a signal switching matrix

Claim 2

A lighting control circuit having dimmers for controlling the brightness of lamp groups, at least one fader for controlling the dimmers, selectors controlling switches to assign each fader to any one of a set of dimmers, and means for recording lighting plots representing brightness settings of all dimmers and for controlling the dimmers in accordance with the recorded lighting plots, characterized by a time multiplex system having a register, each state of which defines a channel corresponding to a different one of the dimmers, and by a matrix comprising an arrangement of the said switches and of groups of enabling terminals, one group being connected to the register and at least two other groups to separate sets of selectors and the connection of the switches to the enabling terminals being such that operation of one selector in each set selects a channel for connection to a fader.

Claim 3

Lighting control apparatus comprising a plurality of lamps, individual dimmer means for setting the brightness of each of said lamps, a plurality of control means generating lamp brightness control signals, and a switch matrix connected to the control means to select one of the control means to control the dimmer means, said switch matrix comprising a plurality of switches, and at least two groups of enabling terminals, each switch being connected to a single enabling terminal in each group whereby each switch is operated only when an enabling signal is applied to each of the enabling terminals to which that switch is connected, wherein each said control means comprises a section of a file store for information representing lamp brightness, in which each control means comprises a fader which supplies signals representative of a desired brightness or a desired rate of change of brightness, and the switch matrix is connected to select one of the faders to control one oF the dimmer means, wherein one group of enabling terminals of the switch matrix is connected to a timing circuit supplying a repeated sequence of pulses for operation of the switches in sequence to repeatedly scan the faders.

Claim 4

Lighting control apparatus comprising a plurality of lamps, individual dimmer means for setting the brightness of each of said lamps, a plurality of control means generating lamp brightness control signals, and a switch matrix connected to the control means to select one of the control means to control the dimmer means, said switch matrix comprising a plurality of switches, and at least two groups of enabling terminals, each switch being connected to a single enabling terminal in each group whereby each switch is operated only when an enabling signal is applied to each of the enabling terminals to which that switch is connected, wherein each said control means comprises a section of a file store for information representing lamp brightness, in which each control means comprises a fader which supplies signals representative of a desired brightness or a desired rate of change of brightness, and the switch matrix is connected to select one of the faders to control one oF the dimmer means, wherein one group of enabling terminals of the switch matrix is connected to a timing circuit supplying a repeated sequence of pulses for operation of the switches in sequence to repeatedly scan the faders.

Claim 5

Apparatus as claimed in claim 2 in which another group of enabling terminals comprises a common terminal connected to a second switch matrix, the second matrix having a group of enabling terminals connected individually to selector switches and a second group connected individually to the timing circuit whereby a pulse is passed to the common enabling terminal of the first switch matrix to select a group of time-divided channels corresponding to each operated selector switch.

Claim 6

Apparatus as claimed in claim 2 wherein the output of the first switch matrix is applied by way of an analogue to digital converter to a buffer store coupled to a core store, the core store holding brightness control information for the lamps and being driven by the timing circuit to read out the stored information into the buffer store sequentially, the output of the switch matrix then serving to change the brightness control information for each of the time-divided channels corresponding to a lamp or group of lamps as required by the fader settings, and the buffer store is connected by way of a digital to analogue converter and a scanner driven by the timing circuit to the dimmer means for the individual lamps.

Claim 7

Apparatus as claimed in claim 4 in which the analogue to digital converter comprises a counter driven by the timing circuit, a series of resistors each of which is coupled to a single stage of the counter, the most significant counter stage being coupled to the highest valued resistor and the less significant resistors to resistors of progressively lower values, and a comparator for comparing the analogue input from the first switch matrix with the discrete signal levels formed by the combined currents through the resistors for each state of the counter.