Determination apparatus

Abstract

The determining device (30) for determining the number (N) of magnetic objects (W) attracted by the magnetic holder (10) comprises: a coil (30c); a determining unit (74) that determines a second voltage (V2) less than the first voltage based on a first voltage (V1), the first voltage being the value of the coil voltage (Vc) at a moment (Tbe) after a specific time (Tb) has elapsed since the start of the coil's excitation; and a determining unit (78) that determines whether the number of magnetic objects is one based on the time (Td) required for the coil to be re-excited after the coil has been energized and demagnetized until the value of the coil voltage reaches the second voltage. A determination apparatus (30) configured to determine the number (N) of magnetic plate bodies (W) sucked by a magnet gripper (10) includes: a coil (30c); a setting unit (74) configured to set a second voltage (V2) based on a first voltage (V1), which is a value of a coil voltage (Vc) at a point in time (Tbe) after a predetermined time period (Tb) has elapsed since coil excitation started, the second voltage being smaller than the first voltage; and a determination unit (78) configured to determine whether the number of magnetic plate bodies is one, based on a required time period (Td) for the value of the coil voltage to reach the second voltage since the coil was excited again after being excited and demagnetized.

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