Method and a device for controlling a silo unloader

摘要

A method and a device for controlling a silo unloader of the type comprising a first electrical motor for driving a gathering apparatus located on the top of the bulk material and a second electrical motor operating a winch to which is suspended the gathering apparatus for lifting, holding in position at the same level or lowering this gathering apparatus into the silo. The method comprises the steps of measuring the current supplied to the first motor and controlling the second motor for lifting, holding in position at the same level or lowering the gathering apparatus in accordance with the measured value of the current. The control device comprises a current detector and an accurate rectifying amplifier for generating a measure signal in relation with the current supplied to the first motor. This measure signal is applied to a circuit comprising a level detector, a memory circuit, a lowering motion control circuit and circuits for generating a lifting time, a stopping time and a lowering time, these generating circuits acting on the second motor for obtaining lifting motion, holding in position at the same level or lowering motion of the gathering apparatus according to the amplitude of the measure signal. The device may be used in combination with any conventional silo unloader of the type described above used in a farm silo.