| 摘要 |
<p>An electronic control means is utilized in an electrically actuated shift apparatus for a multispeed axle including an electric power source and an electric motor coupled to actuate means for shifting the axle. Four Darlington pairs are connected in a bridge configuration between the power source and the armature of the motor for bi-directional operation of the motor. A manually actuatable shift lever has magnetic means attached thereto for generating magnetic shift signals to magnetically actuatable switches. The switches are connected in pairs with each pair alternately connecting a capacitor to the power source to charge and then connecting the capacitor to the input to a control Darlington pair which turns on two associated Darlington pairs of the bridge to allow current to flow through the motor for one direction of rotation. In the same manner, the other pair of switches is actuated in the opposite sequence such that the other one of the capacitors is charging while the one capacitor is discharging to operate the motor in the desired shifting mode. The discharging time of each capacitor is selected to fall between the minimum time required to actuate the motor and associated shift mechanism to shift from one speed to the other and the probable burnout time of the motor. In an alternate embodiment, the Darlington pair bridge is replaced by a pair of diode transistor combinations with each transistor alternately being turned on by the associated capacitor. The switch pairs are replaced by a single pole, double throw switch connected between the power supply and the diodes to provide power to the motor and charge the capacitors.</p> |
