804,838. Electric remote control systems. JAMIESON, J. I. A. May 27, 1957 [March 8, 1956], No. 7261/56. Class 40 (1). Remote-control apparatus includes at the control unit and controlled object a rotary selector switch the wiper of which is coupled to an electrically-controlled escapement to be stepped unidirectionally round a bank of alternate X and Y contacts and escapement-control means for causing the escapement to step the wiper from any of said X contacts to the ensuing Y contact on energization of said means and from said Y contact to the ensuing X contact on de-energization of said means. Transmitter, Fig. 1.-The wiper 11 of a rotary selector switch 10 with ten contacts O, A to I is stepped round under the action of an electromagnet 19 whose armature 16 is part of an anchor lever 15 which is adapted to release for a one-tenth rotary anticlockwise movement a five-toothed spring-biased star wheel 13 on energization and on de-energization. The electromagnet 19 is energized by a source 20 on closure of contacts 21 of a relay 22 which also operates contacts 23 to send a radio signal to the receiver when energized. The relay 22 is supplied from the source 24 through the selector switch 10 and push-button switches e, a to i. The switches b, d, f, h are normally closed and the corresponding contacts B, D, F, H are called X contacts whereas the switches a, c, e, g, i are normally open and the corresponding contacts A, C, E, G, I are called Y contacts. On simultaneous operation of the switch o and one of the switches a to i, say b, the wiper 11 is stepped round under the control of the escapement until it engages the contact B when it stops. When both switches o and b are released the wiper 11 is stepped on to its normal position engaging the contact O. Thus a number of pulses corresponding to the switch operated is transmitted. The spring biasing the star wheel 13 may be rewound under the action of a motor 25 energized by the battery 20 under the control of a switch 251 which may be ganged to switch i as shown. To facilitate operation of the switches, a ganged array (Fig. 3, not shown) may be employed. Receiver, Fig. 4.-At the controlled object which may be a model vehicle the wiper 27 of a rotary selector switch 26, Fig. 4, is stepped round under the action of a five-toothed spring- biased star wheel 29 which is released for a onetenth rotation on energization and on deenergization of a relay 35 which operates its change-over contacts 34 to rock an anchor lever 31. The relay 35 is energized each time the contacts 23 of the transmitter relay 22 close. Thus when one of the transmitter switches a to i is operated, the receiver wiper 27 is stepped round to the appropriate contact A<SP>1</SP> to I<SP>1</SP>. The contacts of a double-pole change-over switch 39 are arranged to be changed over mechanically on each rocking movement of the armature 31 to thereby provide alternative polarity current sources. The contacts A<SP>1</SP>, B<SP>1</SP> are connected to a reversible D.C. motor 36 coupled to the steering gear of a controlled model vehicle by circuits containing limiting switches 36<SP>1</SP> which open when the steering has been advanced to the maximum extent in the corresponding direction. The speed and reversing of the model is controlled by a second reversible D.C. motor 37 which drives a reversible rheostat 51 to control the propulsion motor (not shown) through the leads 53. One terminal of the motor 37 is connected to the contacts C<SP>1</SP>, F<SP>1</SP> through limiting switches 41, 42 which open automatically when the line of the sliders 54, 55 is horizontal corresponding to a maximum vehicle speed in forward or reverse direction, this terminal also being connected to the contacts D<SP>1</SP>, E<SP>1</SP> through another limiting switch 43 which opens when the sliders 54, 55 are vertical to disengage the propulsion supply source 52 owing to the gaps 56, 57 in the rheostat. The contacts G<SP>1</SP>, H<SP>1</SP> are connected to a motor 44 for effecting a gear change. The contact I<SP>1</SP> is connected to a motor 45 for winding up the spring biasing the star wheel 29. The contact O<SP>1</SP> is connected to a signal lamp 46 which shows when the control gear is in readiness with the wiper 27 at O<SP>1</SP>, and hence if the lamp fails to light when the wiper 11 of the transmitter is at O, synchronism may be regained by operating the switch 23<SP>1</SP>, Fig. 1, to thereby step round the wiper 27 as required. If it is desired to obviate the unwanted momentary currents passed to the control gear as the wiper 27 steps quickly over intermediate contacts, the arrangement for reversing the polarity supplied by the source 38 may be modified (Fig. 5, not shown).