| 摘要 |
<p>Power is supplied to a traction motor 26 by the series combination of a battery 30 and the output of a d.c. to d.c. converter machine 10, e.g. a Metadyme supplied via primary brushes 16, 18 from a further battery 20 and having secondary brushes 22, 24 adjustable to vary the motor voltage. In this way, only part of the power for the motor 26 has to be handled by the controller 10. If the batteries 20, 30 have equal voltages, the range of motor voltages is zero to twice battery voltage; if the battery 20 has a higher voltage, an even wider range, including reverse, is obtained. In Figure 6 the voltage across motor 40 is the sum of the voltage of battery 32 and the adjustable voltage of the generator 38 of a Ward Leonard set 34, 38. In a further embodiment, Figure 7 (not shown), the generator (48) is in series with a portion (V2) of a battery to control the motor (50) until closure of a switch (54) cuts out the generator and applies full battery voltage (V1 + V2) to the motor, whose field may then be varied to produce further speed control. <IMAGE></p> |
