A mowing machine comprises a base, a motor, a pulley transmission set, a blade set, a battery, a switch and a detector. The pulley transmission set comprises a first turning wheel, a second turning wheel and a transmission belt which transmits the second turning wheel. The outer diameter of the first turning wheel is smaller than that of the second turning wheel. The blade set rotates along with the second turning wheel. The detector includes a sampling resistor and an amplifier circuit electrically connected in parallel with the sampling resistor. The amplifier circuit can detect current change and trigger the switch to protect the motor. By using the sampling resistor with a small resistance value, the switch is triggered so that the motor is protected and power consumption is decreased. In addition, the motor drives the blade set through the pulley transmission set to decrease the friction and power consumption, thus the motor can be driven by the battery.一種割草機,包含:一基座、一馬達、一皮帶輪傳動組、一刀片組、一蓄電池、一切換器,及一偵測組。該皮帶輪傳動組包括一第一轉輪、一第二轉輪,及一傳動該第二轉輪的傳動帶。該第一轉輪的外徑小於該第二轉輪。該刀片組可隨該第二轉輪旋轉。該偵測組包括一取樣電阻,及一並聯取樣電阻的放大器電路。該放大器電路可透過該取樣電阻偵測電流變化,並觸動該切換器保護馬達,即利用小電阻值的取樣電阻,來觸動該切換器,兼具保護馬達並降低電能耗損,此外,該馬達是透過皮帶輪傳動組來帶動刀片組,而減少摩擦力與功耗,因此可由蓄電池驅動。10...割草機2...馬達3...刀片組4...皮帶輪傳動組5...偵測組51...取樣電阻52...放大器電路6...切換器61...靜磁鐵62...彈性件64...線圈65...動磁鐵66...第一接觸件67...第二接觸件7...蓄電池
