Huka Skwirrel II, Service Manual

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11.3 the Power Module.
The PM (Power Module) , this unit controls and checks the drive motors of the wheelchair.
PM module
The powermodule (PM) executes the drive commands which come from the JSM module. The unit also
receives feedback from the motors. These two kinds of data are checked with each other to make sure the
wheelchair does exactly what the user is telling him to do. Any errors concerning the motors, brakes and
communication is registered here as well. It will store the codes and also send them to the JSM module to
be displayed on the display.
The error codes can be read by a PC as well. On the module is an additional connector for charging the
batteries. There is also an inhibit input connector. The module is protected against short circuit, overload,
dust and water.
11.4 the speed kit (optional for 10 km/h version.)
The speed kit is used to make sure the wheelchair keeps it course when driving at high speeds. It includes
a small electronic unit, a speed sensor and an actuator to activate the damping. The driving speed is
measured by the speed sensor. At a speed of about 4 km/h the system will activate the actuator inside the
rear axle. This actuator is pushing a damping device onto one of the rear castor wheel axles. This way the
wheelchair is prevented from the so called “fishtail effect”. When the actuator moved out into its end
position, it will also press a position switch. This is the feedback to the main PM module to tell the system is
activated. By this signal the maximum speed of 10km/h is released.