Vibration Research Corporation VibrationVIEW, Manual

Page: 193 / 333

Test Definition 180
© 1995-2005 Vibration Research Corporation. All rights reserved.
Select MIL-STD Pulse Limits check box to enable MIL-STD constraints on the pulse. These limits
enable the following tolerances:
· Tolerance is +/- 5% of the peak acceleration for one pulse width prior to the pulse.
·
Tolerance is +/- 15% of the peak acceleration during the pulse
·
Tolerance is +20% -30% of the peak acceleration for one pulse width after the pulse
The starting drive limits and running drive limits are also entered here. The starting drive limits apply
while the controller is equalizing the pulse (i.e. while the test is starting). The running drive limits apply
after the output level has reached the demand level (i.e. while the test is running).
The Max output parameter defines an absolute voltage limit on the output. If this voltage is exceeded
(in either the positive or negative direction) the test will abort.
The Max system gain parameter defines a limit relative to the output. The peak output voltage will not
be allowed to exceed the peak acceleration value of the input signal multiplied by this system gain
value. This is a safety limit that will prevent the controller from outputting a pulse if there is no
accelerometer connected to the system.
Appropriate values for the drive limits depend on your shaker and amplifier system. Typically you
should first run the test to determine when peak output voltage is required. Then set the
Max Output
parameter to about 150% of the required level and set the Max System Gain parameter to 2 times the
peak output voltage divided by the peak acceleration.
4.4.5 Channels tab
Shock Define Control Channels tab
Clicking the "Channels" tab on the Test..Edit Test Settings dialog box accesses this dialog box.
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