| This low-voltage version of our dual
serial motor controller (DSMC) is designed specifically for
high-performance, low-voltage toy
motors that run on 1.5 - 6 V. Because they run at
lower voltages, these motors have higher current requirements, making
them difficult to control since most integrated motor drivers are
designed either for low-current, low voltage motors (such as those in CD
players or cameras) or for higher-voltage motors that run at 6 volts or
more. With this latest motor controller, you can consider a whole new range
of motors for your next high-performance robot.
Due to the unique design of the low-voltage motor
controller, there is no minimum motor supply voltage, meaning that a
motor can be run off of a single cell until it is completely discharged.
In a typical application, two to five Ni-Cd or Ni-MH cells can be used
throughout their discharge cycle. The motor controller can deliver up to
5 A continuously to each channel, without a heat sink, and like our
other dual
serial motor controllers, the two output channels can be coupled
to deliver up to 10 A to a single load. Since many small Mabuchi
motors (such as those used in the Tamiya
gearboxes) have stall currents in the 2 - 4 A range,
you can drive them to the limits of their performance.
In addition to the motor supply, the controller
requires an independent 3.0 - 5.5 V logic supply, which
can be higher or lower than the motor supply voltage. This can be useful
if you have 3 V motors that you would like to run off of two or
three cells but have 5 V logic. If you do have a single supply that
satisfies both requirements (which would typically mean 3 or 4 cells),
the motor controller can be powered off of a single supply. Each motor
has a corresponding pair of LEDs that light up without the motor supply
to let you troubleshoot your code without your robot driving away.
The 9-pin module is pin-compatible and
code-compatible with our micro
dual serial motor controller, making it easy to upgrade your
existing robot to higher performance. The low-voltage motor controller
shares all of the features of the micro
motor controller except for coasting: setting speeds of 0 in forward
or reverse will result in braking.
Application notes
Please note that the low-voltage motor controller can become very hot
during operation; observe proper precautions around a running unit. A
heatsink can improve performance, but it is not required. The motor
controller does not feature over-current or over-temperature shutdown.
Applying reverse battery polarity or attempting to draw too much current
will cause permanent damage to the motor controller.
For high-current applications, make sure to use
the thickest and shortest wires possible. Make sure your motors have 0.1 uF
capacitors installed across their leads to limit noise and interference
with your other electronics. Make sure that your battery can deliver the
current that you attempt to draw: typically, you should have at least 1
amp-hour of capacity per 10 amps you draw (which would give you about
five minutes of operating time). Please read the manual
for detail.
Device specifications
| PCB size: |
1.0" x 0.9" |
| Motor ports: |
2 |
| Speeds: |
127 forward and backward,
brake |
| Max current: |
two motors 5 A each, one
motor 10 A |
| Motor
voltage: |
0 - 7 V |
| Logic
voltage: |
3 - 5.5 V |
| PWM
frequency: |
two motors 600 Hz, one
motor 750 Hz |
| Serial baud
rate: |
1200 - 192000
(automatically detected) |
|
