Patent GB-551194-A (GB)
Title: Improvements in or relating to calculators for electrical networks
IPC: G06G7/63
Filed: 1941-11-11
Abstract: 551,194. Current and voltage measurements. WESTINGHOUSE ELECTRIC INTERNATIONAL CO. Nov. 11, 1941, No. 14521. Convention date, Nov. 13, 1940. [Class 37] A calculator for metering a miniature replica network having electrical characteristics proportional to an actual distribution network comprises a set of conductors connected to metering equipment, and means operable by remote control for connecting any desired selected portion of the network set up in the calculator to the conductors so as to meter that portion. A portion of an actual network is shown in Fig. 1 and comprises a generator 200 supplying a load 201. The impedance and capacitance of the transmission line are represented by an impedance 204 and a condenser 205. Conductors 206 represent other transmission lines making up a transmission network which it is desired to analyse. In solving the circuit the entire network is set up on the calculating board, Fig. 2B, using power sources ; impedances, and condensers proportional to the known characteristics of the actual network. Only the parts shown in Fig. 1 are shown set up in Fig. 2B, the impedances 201a and 204a, condenser 205a and generator 200a representing the corresponding elements in Fig. 1 and being proportional to their values. Conductor buses A1, A2, Cl extend throughout the calculator board for connecting selected circuit portions to the measuring apparatus, which comprises an ammeter A, voltmeter V, and wattmeter W, Fig. 2A. This connection is effected by measuring relays MR1, MR100, MRC19, MRPS8 controlling respectively the impedances 201a, 204a, the condenser 205a, and the power source 200a. When the relay MR1 is energized it connects the impedance 201a between the buses A1, A2, and also one terminal thereof to the bus Cl. Similar arrangements apply to the other measuring relays. The selective energization of the measuring relays is effected by a number of set keys arranged in three groups at a single control board or location. These are in three sets, the first set SK000, SK100, SKPS, and SKC controlling the energization of the buses 000, 100, PS, and C through relays 000<SP>1</SP>, 1001, PS<SP>1</SP> and C<SP>1</SP> respectively. The power supply and condenser circuits are connected to the buses PS, C respectively. The second set of keys SK00 ... SK90 control the energization of the buses 00 ... 90, whilst the third set SK0 ... SK9 energize the buses 0 .. 9 through relays 0<SP>1</SP> ... 91. After the selected circuits have been set by the corresponding set keys, they are energized from the positive terminal of the supply by depression of the start key S. Relays (000)00 ... (000)90, (100)00, C(00), C10, PS(00) are thereby actuated and operate the selected measuring relays. Relays X(000), X(00), X(0) then close holding circuits, which may be opened by depression of a reset key RK so as to restore the entire system to its original condition. Each of the metering relays MR1 &c. is provided with additional contacts 300 which close the circuit of an indicating lamp 302 to indicate which circuit is being metered. Each metering relay may also have manual energizing means such as a push button 304.