GB1103920A - Improvements in or relating to remote control systems - Google Patents

Abstract

1,103,920. Selective control circuits. MARCONI CO. Ltd. 11 May, 1965 [15 July, 1964], No. 29156/64. Heading G4H. A remote control system comprises a series of control lines 6, Fig. 2, to one of which is applied a datum potential (earth), a selector switch 1 movable to contact the lines in turn, a stepping magnet 5 for advancing the switch and a relay 9 the coil of which is connected in the wiper arm circuit and has a contact 10 to de-energize the stepping magnet when the relay is operated. Another contact of the relay operates a lamp to indicate that the switch has reached the desired position. The switch is enabled only when contact 11 is closed and a number of switches may be provided connected to the same group of lines and selected for operation by closure of the corresponding contacts 11. In Fig. 3 the settable switch 12 may be controlled by a local control position 13 or by a remote control position 14. There are a series of five decade switches 17, 18 &c. for controlling a frequency synthesizer. The stepping coil 5 for switch 17 is controlled through a relay 20 connected in series with switch 11 and contact 10 of relay 9. Contacts 21, 22 of relay 9 give indications respectively at the remote control position 14 and at the local position 13. Line selection at the local position is by selector switches 23, 23a &c., one for each decade, the control contacts 10, 10a &c. being connected in series so that the switches 17, 18 &c. are set in correct order. For remote control the earth connections of the wipers of control switches 23, 23a &c. are broken and the earth signals applied by switches 14.