GB790719A - Script display system including switching apparatus for control of auxiliary electrical circuits - Google Patents

Abstract

790,719. Switching systems. TELEPROMPTER CORPORATION. Dec. 28, 1955 [Aug. 4, 1955], No. 37109/55. Class 38 (4). In a script display system a switching system is incorporated so that when a speaker is delivering the material set out on the display, accompaniments-such as the switching on or off of lights, starting or stopping of music, film projectors or the like-may be arranged to take place at will. Such a switching system comprises a number of relays 41 each controlled by a gas-filled valve 8, the contacts of each relay and the grid of each valve being connected to jacks in a section 43 of a panel 4. A number of output connectors 12 are provided together with a similar number of output control switches 14, the terminals of each of which connectors and switches are also connected to jacks in a section 47 of the panel 4. The panel 4 is also provided with a number of earthed jacks GR and a number of jacks P1, P2 which are connected to the supply indicated by a lead 16. In operation the apparatus forming the accompanimentshown in Fig. 6 as a spotlight 60-is connected to an output connector 12 and jumper leads 62, 64, 66 are arranged between jacks F, P2; C1, P1; and N01, A respectively. Closure of switch 5 energizes the circuit and after a time delay valve 10 has operated H.T. is applied to the valve 8. This valve does not conduct since it is biased off by means of a rectifier 48 and condenser 50. As the script display progresses a conductive strip thereon, represented by contact 381, is arranged to earth the grid of the valve so allowing it to conduct and energize the relay 41 thereby causing the light 60 to be lit. A circuit for maintaining the grid of the valve 8 earthed when the display has moved on is formed by jumper leads 68, 70, 72 between jacks G, N02; C2 to jack Cl of a second relay and jack NC1 of this second relay to an earthed jack GR respectively. The first valve 8 is maintained conductive until a second conductive strip on the display arrives to earth the grid of the second valve to render it conductive and energize the second relay thus causing the light 60 to be extinguished. The switch 14 is provided to enable alternative automatic or manual operation to be had and jacks C-, C+ are provided to allow capacitance to be inserted to give a time delay to the relay. Lamp 17 is an indicating lamp and push 15 is a disenabling switch. Jacks T are provided for use as desired. Specification 710,385, [Group XXXVII], is referred to.