| 摘要 |
PURPOSE:To accurately stop a wiper blade in its prescribed lowest position, by determining a slippage angle corresponding to the revolution speed of a wiper motor and by automatically controlling the electrical current cut-off timing of the motor depending on the slippage angle. CONSTITUTION:The rotation of a wiper motor 3 is controlled by the selective connection and disconnection between an annular electrode 1 and the contacts a-c of a cam plate 2 attached to the shaft 4 of the motor. When a wiper switch 7 is turned off during the wiping action of a wiper blade, a relay 16 is energized through a comparator 12 for a prescribed time so that the electrical current to the wiper motor 3 is not cut off in a position A but is cut off in another position B. As a result, the motor 3 slips from the position B by an angle theta1 corresponding to its then actual revolution speed and thereafter accurately stops in a center line position X corresponding to the lowest position of the wiper blade.
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