14
Advanced DC Motor Control
Dc operation with sounds creates a dilemma. The train usually will start moving at a very low
track voltage, to low to power a loudspeaker with high quality sounds. A higher voltage of
operation for the motor is an acceptable solution. About 8.0 volts is necessary before this sound
system can function, producing loud, high quality sounds,
with
the motor powered and the train
beginning to move. This motor controller gives acceptable motor control at the necessary power
levels,
allowing the sound system to start at a much lower voltage
, keeping the motor from
stealing the power from the sound system until enough power exists to move the train without
the sounds degrading or shutting off. Also, more overall power is diverted to the motor at top
speeds. The maximum train speed is higher with this advanced DC motor controller.
DC motor control may be altered by changing the control curve as well as the power curve.
and
determine the control range for DC operations. Altering these values
changes the train’s startup behavior relative to track voltage and at what control voltage full
speed is attained. The power curve may be altered by the speed table (
bit4=0 or (
if bit4=1.
must
be equal to 1.
CV249
defines the maximum track control voltage without applying motor power. Valid values
are 0-255. The distance between
and
keep the control voltage (Track Voltage) from moving between motor off and motor on due to
track voltage variances.
must be smaller than
Vmin
Vmin (
) defines the track voltage that applies the lowest or starting motor power. Valid
values for Vmin are 0-255. The distance between Vmin and Vmax (Vmax > Vmin) is the
control range. This control voltage value determines the locomotive speed.
Note: Vmin < Vmax. Too low a value for Vmin may cause the sound unit to reset when
power is supplied to the motor
.
Vmax
Vmax (
) defines track voltage that once reached sets the locomotive to its fastest speed.
Valid values for Vmax are 0-255. Increasing Vmax means a higher track control voltage is
needed before the maximum speed is reached.
Note: Vmax > Vin. Too high a value for Vmax may not allow the train to reach full speed.