Patent GB-441461-A (GB)
Title: Improvements in and relating to control systems for colour lighting apparatus
IPC: H05B37/02
Filed: 1934-04-11
Abstract: 441,461. Control systems for incandescent lamps. HOLOPHANE, Ltd., and WILLIAMS, R. G., Holophane House, Elverton Street, Vincent Square, London. April 11, 1934, Nos. 10954 and 27742. [Class 38 (iv)] [See also Group XXXVII] Resistance and thermionic controls.-A lighting-control system comprises several units each composed of several groups of lamps, R, B, G, each of the groups having a brightness control 13 operated from a common stop switch 2a which preselects the stopping position of the brightness controls through one or more hunting switches 14 operated by the brightness control means. Each unit comprises three groups of lamps, R, G, B, red, green and brown controlled by series, motor operated resistances 13. Three position switches 9R, 9G, 9B control contactors 19, 12 in parallel and in series with the resistances 13 so that the control of each group is either under the step switch 2a or each group is switched full on or off independently of the switch 2. The controller 2 comprises three banks of contacts 16 each bank being connected to the corresponding hunting switch and all banks being controlled by a common lever or hand wheel control 18 under the control of a switch 8. The lamps are supplied from a main M and the control circuits from a low tension main LT. The control panel of one of the units carries colour master control switches 10R, 10G and 10B which have two positions in which the various colours are controlled by their respective controllers 2 or are switched off independently of them. A third position may be provided for switching all the lamps full on. The control is effected through the relay controls 19 and 20 on the dimmer of each lamp group. Switches 11 and 12 are also provided, switch 11 switching the controllers 2 of all the panels into and out of operation and switch 12 switching the lighting current for all the lamp groups on and off through the relays 20. The dimmers are operated from reversible motors 26 through gearing 27 or they may be driven from a shaft clutchable to a continuously rotating shaft so as to produce rotation in opposite directions on the operation of electromagnetic control means. The resistance 13 comprises two parts 13a, 13b, Figs. 3 and 4, mounted on two panels spaced apart and tappings are brought out to contacts 22 on the inside face of each panel. A bar 24 pivoted at 23 and operated through a lever 29 from the gearing 27 carries a contact 25 which bridges the space and connects the contacts on the panels of the resistance. The hunting switch 33 is driven from the gearing 27 through levers 30, 31, 32 and comprises a rotatable shaft 37, Fig. 5, carrying notched cams 38 which operate push rods 39 controlling spring contacts 34 which operate between contacts 35, 36. The contacts 34 are connected to the respective contacts on the hand controller 2 and contacts 35 and 36 are connected to the means controlling the direction of rotation of the shaft driving the resistance arm. When a position is preset by the hand controller 2 a particular spring 34 is energized and the control means energized to drive the resistance in the requisite direction. The shaft 37 is also operated until the cam 38 controlling the pre-selected spring 34 operates to break the circuit between contact 34 and the corresponding contact 35 or 36. Further rotation of the shaft 37 brings the spring 34 over to the opposite contact 36 or 35 for reverse rotation of the resistance control. Alternatively a number of dimmers may be controlled from a common shaft through cams. Instead of resistances in series with the lamps, grid controlled discharge tubes may be used in which case the motor actuated resistances are in the grid circuits of the valves. The main controller 2 comprises a fixed plate, Fig. 7, carrying contacts 16 and a movable arm 18 carrying contacts 17, mounted on a shaft 2a connected to the hand wheel 2. The shaft 2a displaceable axially against the bias of a spring 40. The hand wheel 2 carries an extension 3 and projection 4 which engages apertures in an indicator 4. The hand wheel is operated by pushing inwardly so as first to disengage contacts 16, 17 and then rotating g it to the desired position. Alternatively the contacts of the controller may be arranged in a complete circle and the control shaft is continuously rotatable through a drive from a ratchet wheel operated by a pawl which is oscillated from a motor operated crank. This arrangement provides repeating colour effects. Each panel carries a pilot lamp which is arranged to be on when any hunting switch controlled by that panel is in operation. Specifications 396,790, 411,868, and 412,217 are referred to.