Page 6 - HR500 User Guide - 2016-USA Version Hensler_Neat

ii. Size-and cut process
The rotor, rotating at high RPM, creates radial centrifugal forces acting on the bone chips
forcing the chips against the blade. The rotor sweeps the bone chips over the surface of the
blade that allows the cutting teeth of the blade to size and cut portions of the chips smaller
than the sizes of the apparatuses located in front of the cutting teeth. The sized morsels are
forced to eject themselves through the blades, falling in the catch-container. The angled
leading side edges of the cutting teeth accomplish the sizing process.
iii. Particle-size reduction
With control and no bone loss, re-milling a portion or all of the already-milled particulates
provide reduction in the particle sizes. Mixture of the first-mil and the second-mill provides a
wider particle-size-profile.

C. Source of Milling Power
A high torque, 24 volts, brushless DC motor provides the needed rotational power. Located inside
the battery-power-pack, analog-digital electronic circuitry on a printed circuit board, the driver
board, provides the three phase 24 volts power for the motor. Another analog electronic circuitry
on a separate printed circuit board, the controller board, provides for controlling the driver board.
The controller board includes the electronic circuitry components for individual balance charging
of seven 3.2 volts lithium iron phosphate batteries.

D. Battery Charging
A 24 volts DC medical grade power supply provides the charging current for charging the
batteries. The power supply is located in an aluminum cage. For safety, the primary and the
secondary stages of the power supply and the outside metal surfaces are positively connected to
the earth (ground).
Each of the seven batteries is first charged to 3.5 volts (Red and yellow lights indicate charging in
progress) and then held at the recommended 3.34 volts indefinitely (green light).

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