American Magnetics 4Q1010PS-430 Integrated Power Supply System - Manual (Page 51)

Rev. 5 33
Operation
Shift Key Commands : Ramp Rate
menu, for example, press the SHIFT key, and then press the VOLTAGE
LIMIT key (also the 2 key). Note that some of the SHIFT-key menus can
also be accessed using the setup menu.
Pressing the ESC key or the SHIFT key a second time will clear the SHIFT
function and return the keypad to it's numeric function.
3.7.1 Ramp Rate SHIFT-key
Use of the RAMP RATE SHIFT-key provides a menu for setting ramp
rate(s). The ramp rate may be set
1
within the range specified for the
specific Model 430 Programmer configuration (refer to specifications on
page 8). If field units are being used, then the ramp rate setting is
displayed and set in units of kG/sec or T/sec). The allowable range is then
defined by the setting of the coil constant and the allowable range of the
ramp rate in terms of current as specified in the table on page 8. If the
Ramp Segments value 2 is greater than 1, then the menu also allows
setting of the field or current range for which each ramp rate is to be used.
The Model 430 Programmer will ramp at the specified rate if the available
compliance of the power supply is sufficient and the Voltage Limit is not
exceeded. The Model 430 automatically decreases the ramp rate internally
during operation if either the available compliance of the power supply is
insufficient, or the Voltage Limit is active.
3.7.1.1 Ramp Rate SHIFT-key Example
An example (using a magnet with rated current of 60 A
3
) will
illustrate the use of the ramp rate menus. The example assumes
that the field/current units have been set to amperes. and the ramp
segments value has been set to 3. Segmented magnet current
ramping is chosen with rates as follows:
1. ±0.2 A/s from 0 to ±55 A
2. ±0.1 A/s from ±55 to ±58 A
3. ±0.05 A/s above ±58 A.
In the following discussion, the fine adjust knob
4
can optionally be
used for ramp rate adjustment if the persistent switch is heated (or
if no persistent switch is installed). If the user attempts to edit
ramp rate segments using the fine adjust knob while an installed
switch is cooled, the Model 430 Programmer will produce one beep
to indicate an error
5
. Similarly, if the switch is heated (or no switch
1. Using numerical keys per section 3.3 on page 25 or the fine adjust knob (see
section 3.4 on page 26).
2. Refer to section 3.10.3.2 on page 59.
3. In this example, both the Current Limit and Magnet Current Rating are set at the
rated magnet current of 60 A.
4. Refer to section 3.4 on page 26.