| 摘要 |
A portable conductor wrapping tool having a rotary bit driven by an electric motor includes a motor control circuit in which a switch responsive to a magnetic field is disposed in proximity to a drive spindle for the bit and a magnet mounted on the tool housing. A magnetic flux shunt disposed on the spindle distorts the magnetic field of the magnet as the shunt passes through the field causing the switch to open to deenergize the motor and stop the bit and spindle in a predetermined position. The motor control circuit includes a solid state speed control device and a manually actuated switch which in a first position provides full power to the motor and in a second position supplies reduced power through the magnetic responsive switch.
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