Patent GB-190413564-A (GB)
Title: Improvements relating to the Regulation of Electric Motors
Filed: 1904-06-15
Granted: 1905-06-15
Abstract: 13,564. Johnsom - Lundell Electric Traction Co., [Lang, J. G. V.]. June 15. Field magnets ; motors, controlling. -Relates to the regulation of motors, being especially applicable to the system described in Specification No. 329, A.D. 1903, in which the motors are connected up as series motors while propelling and accelerating the vehicle, and as compoundwound generators while braking the vehicle. Thehandle of the controller Ax is provided with a contact A, and is capable of a certain amount of free movement in either direction independently of the controlling-cylinder, so that the contact A may be brought into engagement with either of the contacts A<2>, A<3> carried by the controller, the handle being held by springs in its normal position between the contacts A<2>, A3. With the contacts b<1> of the field-change cylinder B<x> in engagement with the fixed contact B', the motors are in their series condition, while the regenerative condition is obtained by rotating the cylinder B<x> so that the contacts b<2> engage with the contacts B<1>. The device by which the field-change cylinder Bx is actuated consists of a solenoid provided with a shunt coil b<3> and a series coil b<4>, the core being connected to a crank lever b<5> connected with the cylinder Bx and to a spring b<6> or to a weight. When the motors are in their series condition, as in Fig. 1, the current from the trolley passes through the resistance i, contacts 5, 6 of the row B<1>-B<1>, contacts 3, 4 of the row A<1>-A<1>, and armatures d', d<2> to the contact 13, thence in parallel through the fields e', e<2>, e<3>, e<4>, e to the contact 12, and finally to ground through the contacts 10, 11 of the row A<1>-A<1>. If the handle of the controller is now moved so that the contact A engages with the contact A<3>, the controller cylinder remaining stationary, the circuit through the shunt coil b<3> is completed. The field - change cylinder B<x> is thereby turned into the position in which the contacts b', b' engage with the contacts B', B<1>, thus converting the motors into their regenerative condition, at the same time breaking connection between the contacts 5, 6 and thus compelling the generated current from the motors to pass through the series coil b', and also breaking the circuit of the shunt coil b<3> between the contacts 3, 4. If the current generated by the motors falls below a predetermined value, the spring b<6> returns the cylinder B<x> to the position b<1> b<1>, in which the motors are in the series condition. Should the motorman turn the handle in a forward direction when the motors are in their compound condition, the contact A<x> engages with the contacts A<2>, thereby short-circuiting the coil b<4> and thus allowing the cylinder Bx to return to the position b<1>-b<1>. The cylinder B<x> also returns to the position b<1>-b<1> should the connection between the motors and the source of supply become broken, for in such a case the coil b<4> is immediately deenergized. Figs. 2 and 3 represent modifications of the device for actuating the cylinder B<Î>. A tongue b<11>, Fig. 2, is held in its normal position against a contact b<9> by a spring b<12> or by a weight, the coil b<7> being energized by the main current. When either of the circuits of the coils b<3>, b<4> is closed and the current is above a predetermined value, the tongue b<11> is attracted, thereby engaging with the contact b<10> and completing the circuit of the coil b<8>. The coil b<7> may be replaced by a spring b<6x>, Fig. 3. An electric motor may be substituted for the coils b<3>, b<9>.