348,154. Control of motors. SIEMENSSCHUCKERTWERKE AKT.-GES., Siemensstadt, Berlin. Feb. 8, 1930, No. 4357. Convention date, Feb. 28, 1929. [Class 38 (iii).] Following movements of control member.-In a selective remote control system provided at the control station and at the remote station with contact arms movable over a number of contacts, the contact arms at the control station, Fig. 1, are adjustable by hand, and any adjustment from normal zero position causes also the movement of a member 31 away from an insulated member 30 to engagement with one or other of two conducting strips 28, 29, whereby a circuit is established to cause, through stepping mechanism, the parts 30, 31 at the control station to return to normal relationship, the contact arms at the remote station, Fig. 2, being displaced correspondingly but by an electric motor. The control station and remote station are connected by lines 15, 16, 17 and an earth return or fourth line. At the control station a spindle 22, capable of being rotated by a hand-wheel 23 carrying a pointer 24 has three fixed discs 18, 19, 25, the discs 18, 19 having contacts for engagement by the arms 20, 21 respectively, and the disc 25 being formed with graduations to indicate the position of the contact arms and with a window 27 to render visible an indication of the position of the disc 26. This disc which carries the strips 28, 29, is loosely mounted on the spindle 22, and is toothed for engagement by an armature 32 controlled by electromagnets 33, 34. The remote station is provided with three contact discs 117,. 118, 119 the contact arms of which are fixed on a spindle 122 adapted to be driven by an electric motor, each revolution of which causes the arms to be moved from one contact to the adjacent one. A cam 126 on the motor shaft engages a contact maker 125 once each revolution of the motor whereby contacts 127 or 128 are closed, as the result of which the stepping magnets 33, 34 at the control station are energized and the disc 26 moves in accordance with the movement of the contact arms at the remote station. In order to close switch 130 the attendant at the control station, by means of the hand-wheel 23 places the contact arms 20, 21 on to the contacts corresponding to the switch 130, for example, contacts 3. The lever 31 moves from the insulating piece 30 on to the strip 28, the reby closing a circuit through relays 35, 41, 141. These relays act to close a circuit for relay 135 which at contacts 136 completes a circuit to cause the motor to rotate in a certain direction. The contact arms at the remote station move from one contact to the adjacent one with each revolution of the motor, and the pin 126 each time it engages the contact maker 125 closes a circuit for relay 34 whereby the disc 26 is moved a step corresponding to the distance between two contacts. The motor continues to rotate until the contact arms at the remote station reach contact 3 and the insulating piece 30 moves underneath the contact-lever 31. The circuit for relays 35, 41, 141, is then opened causing relay 135 to be de-energized so that the circuit of the motor is opened. The attendant at the control station sees through inspection opening 27 the number 3 indicating that the switch 130 is connected with its control apparatus. To close the switch he presses key 55, thereby short-circuiting relay 56 and enabling relay 155 to operate in a circuit from earth through battery, contacts 157 of switch 130, winding of relay 155, contact 3 of disc 118, contact arm 120, armature 142, line 16, armature 42, contact arm 20, contact 3 and key 55 to earth. Relay 155 acts to close the circuit of switch motor 131 whereby the switch 130 is closed. Closure of the switch opens contacts 157 and closes contacts 158 whereby a return signalling circuit is established through relay 59, which operates to cause lamp 64 to light up. The connections from the contacts of discs 18, 19 may be modified so that instead of using one pair of lamps such as 63, 64 for each switch one pair may be used for all the switches.