Patent GB-190706528-A (GB)
Title: Improvements in Electric Motor Control Systems and in Apparatus therefor.
Filed: 1907-03-18
Granted: 1908-06-18
Abstract: 6528. British Thomson-Houston Co., [General Electric Co.]. March 18. Switches.-A master-control system for electric motors, for example in electric trains, has galvanic batteries, or other source of current independent of the line, connected to train-wires and arranged to operate sets of electromagnetic switches, which switches control series, parallel, and resistance contactors arranged in general in the manner already employed in electropneumatic and other master-control systems. Fig. 1 shows a battery I, controllers K, K<1>, train-wires 1, 2, and one of the several car equipments. The immediate effect of the control is upon a set of electro-magnetic switches F, F<1>, L, G. The windings of the switches F, F<1>, L are all excited when the controller K is moved to the first position on either side, say the right, but the upper winding a<1> of the switch F<1> opposes the action of thelower winding a, while the corresponding windings on the switch F aid each other's action ; thus the contacts f, f<2> are connected and the contacts f<1>, f<3> remain unconnected. A circuit for current from the trolly T is consequently closed along the wire 3 through the contacts f, f<2>, branching on the one hand through the wire 4 to the reversing-switch RS, and on the other hand along the wire 6 to the actuating- coil of the series contactor S, the result being that the motors are connected in series with full resistance. If the first movement of the controller K is to the right, the polarity of the train-wires 1, 2 is reversed, the coils of the switch F neutralize each other, and those of the switch F<1> superpose their actions, so that the circuit from the trolly is closed through the contacts f<1>, f<3>, and the contacts at f, f<2> are disconnected. The result in this case is to send current to the reversing- switch along the wire 5, thus operating it in the other direction, while a current flows along the wire 6 to the series contactor as before. To cause the accelerating action to begin, the controller K is moved to the second position, whereby the coils of the switch G are excited through the controller contact k<10> and ground connexions, all the circuits through the switches L, F, F<1> being unchanged. An additional circuit from the trolly T is then closed along the wire 7, across the upper auxiliary contacts of the series switch S, through the coils of the first resistance contactor R<4>. The automatic cutting-out of the succeeding resistance sections then proceeds in the usual way, a ' bridging' switch B closes, and the parallel connexions are automatically made in the manner already known. In the system shown in Fig. 2, an additional battery Z is employed to excite the switch coils a, and another battery Y to be put in series with the battery I for the purpose of operating a switch H controlling parallel contactors, the operation of the relay G by means of the battery I only sufficing in this case to work the accelerating relays. There are three positions of the controller K<o> on either side, the first producing series connexions by means of the wire 6<a> with full resistance, the second, resistance cut out, and the third parallel connexions. In the second position, current from the battery I flows through the coils of the switches G, H, but is only able to close the switch G. In the third position, the additional power of the battery Y closes H also. Specifications Nos. 11,158, 20,274, and 21,758, A.D. 1898, and No. 18,490, A.D. 1906, are referred to.