Patent GB-201154-A (GB)
Title: Distant control systems for generating stations
IPC: H02J13/00
Filed: 1923-06-20
Abstract: 201,154. Arter, R. C. July 24, 1922, [Convention date]. Selective distant control systems; tell - tale apparatus.-In a system for the control of a number of hydro - electric generating sub - stations from a central station, all the stations are connected over a common line, which may be used for telephonic communication. Each sub-station has a step-by-step switch 22-24, which responds to a characteristic number of impulses from an impulse-transmitter 8 at the central station to enable the station to send back a characteristic audible signal from a microphone 14, and upon receipt of subsequent impulses to transmit audible signals indicating various conditions, such as load and depth of water. Control apparatus may be operated from the central station by the sending of further impulses. Selection of wanted sub-station. Depression of a key 7 reverses the battery and earth con. nections of the common line 5, 6 thereby energizing at each station a polarized relay 9, which operates a relay 19. Line relays 18 are energized in parallel and operate slow relays 10. Impulses are now sent, and at the first relapse of the line relay 18, the ratchet magnet 20 and a slow relay 11 are energized in parallel, the latter retaining its armature until the emi of the train of impulses. The switch 23-24 at each station is thus rotated a number of steps corresponding to the number of impulses, and terminals of the wipers 23 are so arranged that a relay 21 is then connected up and locks itself at the wanted station, and a relay 25 is connected up at the remaining stations, the latter cutting cut the impulse relay 18 so that only the wanted station is effective subsequently. Transmission of signals to the central station. A relay 12 energizes at the selected sub-station, and a relay 26 is energized over the wiper 24, connecting up the ratchet magnet' 37 of a switch 38-41, which is rotated by the interaction of the magnet 37 and a slow relay 36 until the relay 26 is de-energized. The wiper 40 is connected to a bell 15 and a certain number of the wiper contacts are earthed, so that the bell 15 is sounded several times and gives a check signal through the microphone 14. To ascertain thedepth of water, a single impulse is now sent, moving the switch 22-24 a further step. The relay 26 releases and stops the rotation of the switch 38-41, and a relay 30 is energized over the wiper 24, closing a new circuit for the motor magnet 37 and connecting up a bell or buzzer signal 17, which is sounded as the wiper 3) reaches each odd terminal. The even terminals of the wiper 41 are connected to a bank engaged by a wiper 31 set according to the depth of water, for example by a float 32. When a number of signals indicating the depth of water have been sent, a disconnecting relay 35, energized over the wipers 31, 41, locks up and breaks the signalling circuit. The relay 35 is released by short-circuiting. at the last terminal of the wiper 41. Other information may be ascertained in a similar way by means of relays connected to subsequent terminals of the wiper 24 and indicating switches connected to the terminals of the wiper 41. Fault signal. The maximum number of signals in the arrangement shown is eight, but if the indicating apparatus is defective a further fault signal is sent by means of a connection to the seventeenth terminal of the wiper 39. Operation of control apparatus. Further terminals of the wiper 24 are connected to relays such as 27, 28, which close circuits to perform any desired function. Release. On restoring of the key 7, the polarized relay 9 at each sub-station deenergizes, releasing the relay 19 which connects up the magnets 20, 37 over the wipers 22, 38 thereby restoring the switches to normal.