REV-11-1200-UM-00
Copyright © 2016 REV Robotics, LLC
10
The output voltage seen by the motor is proportionally related to the input pulses. A change in pulse results in a
proportional change in motor speed. The approximate output voltage is determined by the following equations:
P
MAX
= Configured maximum pulse width in µs (default 2000)
P
NEUTRAL
= Configured neutral pulse width in µs (default 1500)
P
MIN
= Configured minimum pulse width in µs (default 1000)
p
= Input pulse width in µs
V
OUT
= Approximate output voltage seen by the motor
2.3
HEAT MANAGEMENT
The SPARK uses a method called synchronous rectification when switching the motor output in order to minimize the
heat generated by its H-bridge. Some heating is unavoidable, so an aluminum heat sink passively dissipates heat into
the surrounding atmosphere.
Figure 2-3 Heat Sink
As seen in Figure 2-3, the heat sink is located at the center of the SPARK. For most applications, a cooling fan isn't
necessary, however, airflow should be kept in mind when using the SPARK in high-load applications. The heat sink is
electrically isolated from the SPARK circuit board and components. APPENDIX B shows the temperature at various
internal and external locations on the SPARK while it was under a 40A load for 300 seconds.
CAUTION
Under heavy loading conditions and prolonged periods of high current the SPARK heat sink may become hot. Use
caution when handling a SPARK that has been used under heavy loading conditions.
