| 摘要 |
1,171,915. Lighting control systems. THORN ELECTRONICS Ltd. 18 Oct., 1967 [21 Oct.. 1966], No. 47341/66. Heading H2H. [Also in Division G3] A lighting control system comprises a number (400) of dimmers 10 each controlling the brightness of a corresponding group of lamps and being controlled by a time multiplex system in which a number (400) of channels, one for each dimmer, are time divided by a master oscillator 15 and divider circuit 16 whose outputs are passed to core drivers 17 controlling a digital store 14 and to an output scanner 21 comprising a sampling matrix of AND gates which matrix decommutates the 400-channel time sequential signal from a digital-to-analogue converter 19 into 400 signals which are shaped in the dimmer drive unit 20. The brightness of each lamp group is registered in the store 14 for periodic transfer to and from a buffer store 18, which feeds the D/A converter 19 and is fed by a unit 31. The latter member raises or lowers the brightness count of groups of lamps selectable by a channel selector 13 and a number (10) of faders (only two of which 8, 9 are shown), adjustable from a centre-zero position to raise or lower the lamp brightness to maximum or minimum intensity or until the fader control member is returned to its centre-zero position. The channel selector 13 and an input scanner 22, which are described in Specification 1,171,914, co-operate with the faders to apply the analogue outputs of the latter via raise and dim output wires 23, 24 to a voltage-controlled generator 25 described in Specification 1,171,913, which converts the analogue outputs to digital signals for transmission to the store 18 through the unit 31. Each fader controls a corresponding one of the ten channels selected and alters the lamp brightness at a rate depending on the position from the centre-zero of its control member, which determines the increase or decrease in the brightness count in a predetermined time set by the generator 25. The faders may be of the type in which an analogue voltage is determined by the position of a lever carrying a magnet controlling an array of reed switches or be of the pulse-generating type, in which case the analogue to digital converters 25 is not required although the pulses require retiming by a selection circuit so that each fader controls the desired lamp group. A suitable pulse-generating type fader comprises cams closing a pair of contacts or a series of magnets passing a reed switch or switches. |
