Wilson Manifolds 810100 Progressive Nitrous Controller and Vehicle Data Logger - Manual (Page 11)

Nitrous Pro-Flow, 4700 NE 11
th
St., Ft. Lauderdale, FL 33334 Pro-Flow Part. No. 810100
(954) 771-6216 www.nitrousproflow.com 1/2008
Page 11
If the one-shot timer option is selected, the PWM
ramp timer will only be reset to zero when the nitrous
controller is armed. The PWM ramp will hold and then
resume during a shift. This mode of operation is useful
for a slow (several second) ramp up used to avoid
wheel spin at slow speeds or while in first gear.
PWM Frequency – value (in Hz) of the
frequency used to modulate the solenoids. Consult
with the manufacturer of your solenoids for
recommendations. In general, 15 Hz will work for all
solenoids. Smaller solenoids can tolerate a higher
frequency such as 25-30 Hz. A higher frequency will
result in smoother operation with less torque ripple and
pulsing. However, if you attempt to run a large solenoid
with a heavy core at an excessively high frequency, the
valve may hang up or float at an intermediate position.
This will result in erratic and unpredictable flow.
Enable PWM – PWM control can be
independently enabled for stage 1 and stage 2. If PWM
is disabled for a stage, it will simply be triggered on/off.
If your system only uses PWM on stage 1, you should
disable PWM on stage 2.
Start Time and Final Time – Time based PWM
only. Used to set the start and final times for the PWM
ramp when you click on the Reset to Straight Line
command. Any subsequent edits you make to the
PWM graph override these settings.
Start RPM and Final RPM– RPM based PWM
only. Used to set the start and final RPM values for the
PWM ramp when you click on the Reset to Straight
Line command. Any subsequent edits you make to the
PWM graph override these settings.
Start PWM and Final PWM– Used to set the
start and final percent values for the PWM ramp when
you click on the Reset to Straight Line command. Any
subsequent edits you make to the PWM graph override
these settings.
You can use the start and stop settings and then
click on the Reset to Straight Line command to
generate PWM ramps that will be displayed on the
PWM graph. You can edit the PWM ramps by clicking
on and dragging individual points on the graph. When
you drag a point, the associated percent PWM value
will be displayed in a small box.
For time based PWM, the time axis is in 0.25
second steps. Time is from the trigger event. Please
note that the two stages will only have the same
timeline if identical trigger conditions are used for each
stage. For RPM based PWM, the RPM axis is in 250
RPM steps.
Solenoids valves will have a non-linear response
below 20% and above 80% duty cycle. A minimum
duty cycle, as high as 10-20%, will be required before
any flow occurs. In most cases you should start the
PWM ramp at 20%. Once the duty cycle exceeds
about 80%, the valve will not fully close during the off
time. Thus flow will reach a maximum and not increase
above 80% duty cycle. In most cases, you can have
the ramp go up smoothly to 80% and then let it jump to
100%.
Figure 8 – PC Link Nitrous Timed Based PWM Setup