SoundTraxx Tsunami Steam Technical Reference - Manual (Page 4)

Tsunami Technical Reference Page 2
CV 2
Vstart
Description
Vstart defines the initial voltage level applied to the motor at speed step 1 as
a fraction of available supply voltage:
D0-D7: Motor Start Voltage
Vstart may contain any value from 0 to 255. The starting voltage applied to
the motor may be computed as:
Starting Voltage = Supply Voltage X CV2÷255
where CV 2 is the contents of the Vstart register. A value of 0 corresponds to
a zero starting voltage. A value of 255 corresponds to the maximum available
voltage (100%).
For speed steps greater than 1, the DSD will continue to sum the initial
starting voltage level into the throttle computations which has the effect of
offsetting all points on a given speed curve by the level set by Vstart as
illustrated in the figure below.
Default value: 0
Primary CVs
Bit 7 Bit 0
D7 D6 D5 D4 D3 D2 D1 D0
0 2 4 6 8 10 12 14 16 18 20 22 24 28
SPEED STEP
Vstart = 20
Vstart = 0
MO
TOR
V
O
LT
A
G
E
100%
75%
50%
25%
0%