초록 ▼

A cordless electric mower having an energy management system that allows a user to operate the cutting blade motor of the mower at a wide range of user selected speeds. The mower is provided with a user adjustable throttle control which, when in the wide-open position allows the cutting blade motor

A cordless electric mower having an energy management system that allows a user to operate the cutting blade motor of the mower at a wide range of user selected speeds. The mower is provided with a user adjustable throttle control which, when in the wide-open position allows the cutting blade motor to be rotated at a maximum, predetermined speed. When the throttle is set to some lesser speed, the system automatically implements a speed foldback routine whenever the mower encounters heavy loading which would result in an undesirably high current draw on the battery. When the speed foldback routine is implemented, the system limits the maximum amount of current that can be drawn by the motor until the excessive loading condition has been removed. Once the excessive loading condition has been removed, the speed foldback routine automatically increases the speed of the blade motor back up to almost the originally selected speed. This greatly improves the operating efficiency of the mower and thereby significantly extends the available operating time of the mower on a single charge. The state-of-charge of the battery is also monitored continuously during operation. An LED display provides the user with an indication of the approximate battery charge remaining.

대표청구항 ▼

[ What is claimed is:] [1.] An energy management system for use with a cordless, battery powered electric vegetation cutter having a cutting implement driven by an electric motor, the system comprising:a user adjustable throttle control for setting the speed of said electric motor to a user selected

[ What is claimed is:] [1.] An energy management system for use with a cordless, battery powered electric vegetation cutter having a cutting implement driven by an electric motor, the system comprising:a user adjustable throttle control for setting the speed of said electric motor to a user selected reference speed;a controller responsive to said throttle control for monitoring battery current being drawn by said electric motor and for generating a drive signal in accordance with said user selected reference speed;said drive signal being incrementally reduced by said controller in the event said vegetation cutter experiences an excessive load, causing battery current drawn by said motor to exceed a threshold value, to thereby incrementally reduce the speed of said electric motor while the magnitude of said battery current drawn by said motor remains above said threshold, said drive signal being incrementally increased when said excessive load is removed such that said drive signal is increased at least close to the magnitude it was at prior to said cutting implement encountering said excessive load; anda switching circuit responsive to said drive signal for applying power to said electric motor from said battery.