Pololu TReX - Manual (Page 5)

TReX motor connections (single battery)
The figure above demonstrates how to connect two bidirectional motors and a unidirectional auxiliary motor to your
TReX, all powered by the same battery. Note that the auxiliary motor is driven by permanently connecting one lead
to power while the board PWMs the other lead between high impedance and ground. You must connect your battery’s
ground directly to the lower port of the auxiliary motor’s connection block if you plan to use the auxiliary motor.
Otherwise, the auxiliary motor could attempt to pull too much current through the TReX itself, thereby damaging the
unit.
The auxiliary motor’s other lead connects to the upper port of its connection block. You will need to connect a diode
across the auxiliary motor’s terminals as shown below. Failing to do so will adversely affect the performance of your
TReX and could result in permanent damage to the device. Take great care to ensure you do not solder the diode in
backwards! You should not solder a diode to your bidirectional motors.
You may find it beneficial to solder 0.1uF capacitors across all of your motors’ terminals. This will decrease the noise
put out by your motors and can improve performance of your TReX. You can further decrease the noise put out by
your motors by keeping their leads as short as possible and twisting them around each other in a helix.
Option 2:
Pololu TReX User's Guide © 2001–2013 Pololu Corporation
3. Getting Started Page 5 of 24