3.22EjemploDRM007 Co..

Introduction and Setup
The Hall sensor signals are scanned independently of the speed
controller. Each new incoming edge of any Hall sensor signal calls an
interrupt routine, which calculates a new voltage shape, applied to the
BLDC motor. This process is called commutation. The PWM
transistors work in complementary mode, when the upper transistor is
on, the lower transistor is off and vice versa.
1.8 Warnings
This reference board operates in an environment that includes
dangerous voltages and rotating machinery.
Due to the high-voltage power stage operating directly from an ac line,
oscilloscope grounds and power stage grounds are at different
potentials, unless the oscilloscope is floating. Note that probe grounds
and, therefore, the case of a floated oscilloscope, are subjected to
dangerous voltages.
• Before moving scope probes, making connections, etc., you must
turn off the main switch.
• Operation in lab setups that have grounded tables and/or chairs
should be avoided.
• Wearing safety glasses, avoiding ties and jewelry, using shields,
and operation by personnel trained in high-voltage lab techniques
are advisable.
• Never turn on the board in running mode if it is not known if the
code is downloaded.
• To reduce the cost of the board, optoisolation circuitry was not
included: the microcontroller’s ground is tied to a power stage
ground. For this reason, special care must be taken when
handling the board. Touching its components when it is turned on
must be avoided.
DRM007
BLDC Motor Control Board for Industrial and Appliance Applications
32 Introduction and Setup MOTOROLA