| 摘要 |
A trailer jack system includes an electric linear actuator having an electric motor, a source of electric power, and a controller that supplies a first voltage to the electric motor when the electric linear actuator is loaded and a second voltage to the electric motor when the electric linear actuator is unloaded. The electric linear actuator also includes a cylindrically shaped housing, a leg coaxially extending and retracting from the housing, and a support foot at a free end of the leg. The controller supplies the first voltage to the electric motor when a motor current of the electric motor is below a predetermined threshold value and supplies the second voltage to the electric motor when the motor current is above the predetermined threshold value. Preferably, the first voltage is about 24 volts and the second voltage is about 12 volts.
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