Patent GB-433235-A (GB)
Title: Improvements in or relating to electrical systems of remote supervision
IPC: G01R11/16
Filed: 1934-05-24
Abstract: 433,235. Electric signalling systems. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, and SMART, N. C., c/o General Electric Co., Stoke, Coventry. May 24,1934, No. 15500. [Class 40 (i)] In a telemetering system in which meter readings to be transmitted are summated on decimal recorders, such as step-by-step switches, and the positions of the recorders are transmitted periodically to a control station, the recorders are re-set as soon as their positions have been transmitted and at once re-commence summating. The reading of the fastest moving (units) recorder is not transmitted and readings of a number of sets of recorders may be transmitted by using a suitable distributer. The apparatus at the remote point is indicated in Fig. 1 and that at the control point in Fig. 2. The meter is indicated at 17 and for each revolution magnet D is energized to step wiper D1. When wiper D1 reaches its tenth contact it extends the circuit from 17 to magnet E so that both switches D and E are stepped by the next pulse. Similarly switch F is stepped by each hundredth pulse and switch G by each thousandth. The reading of switch D is not transmitted but switches E, F and G mark contacts in bank H1 of switch H over wipers E1, Fl and G1 respectively. Additional switches to follow G may be provided if the indications to be transmitted necessitate them. When an indication is to be transmitted positive is connected to lead 5 (Fig. 2), for example by a clock so that switches Q, K and J, which are standing on positions corresponding to the last indication, are homed in succession over wipers Q2, K2 and J2 respectively and then relay Y is operated. Relay Y energizes the pendulum magnet W and prepares the circuit for relay X so that as the pendulum swings relay X is pulsed to step switch P and to send impulses to relay M which steps switch H. Relay Y is held over bank P2. Wipers P1 and H1 step together and switch J steps over wiper P1 to keep one step ahead. When wiper H1 reaches the contact marked by wiper E1, relays A and R operate and lock. Relay A enables switch E to restore and when the switch is normal, relay A releases and allows switch E to recommence summating. Relay R reverses the current flow in the line so that polarized relay N is energized and opens the circuit over wiper P1 to prevent switch J stepping further. Wipers P1 and H1 continue to step and when H1 reaches the contact between those marked by wipers E1 and F1, relay R is shorted down to restore the normal direction of current flow over the line. Switch K is now stepped as wiper PI moves until H1 finds the second marked contact, when relays B and R pull up, switch F is reset and switch K stopped. Similarly switch Q is moved to a position corresponding to switch G and switch G is reset. The positions of switches J, K and Q are indicated by drums J3, K3 and Q3 driven by the switches and suitable dummy digits can also be displayed on the panel to show the indication. in the desired units. A printometer may be connected over lead 2 and this may be reset by any known means when a reading has been transmitted, for example by means of a circuit, such as that for relay Y over J2, K2 and Q2, completed over additional wipers of switches E, F and G in their home positions. Readings of a number of meters can be transmitted by using a switch H with a large contact bank or by using a suitable distributer. An alarm may be given if impulse transmission is faulty, and relaying of the signals at an intermediate point in the transmission may also be provided.