AMI 420, Installation, Operation And Maintenance Instructions, Page: 72 / 134

54
Rev. 7
Operation
Ramping Functions : Manual and Programmed Modes
The voltage limit may be entered directly via the keypad or
adjusted using the dial. Attempts to set the voltage limit above the
maximum output of the power supply are ignored and, if
attempted, the instrument will beep once indicating an error and
revert to the previous setting.
3.3.1.2 Ramp Rate
The ramp rate is accessed by pressing the
5$035$7(
key. The
ramp rate may be set within the range specified in the
specifications table for a specific Model 420 configuration (see
page 7). Attempts to set the ramp rate outside of the valid range
are ignored and, if attempted, the instrument will beep once
indicating an error and revert to the previous setting. The ramp
rate may be entered directly via the keypad or adjusted using the
dial.
If the selected default display contains units of field, then the ramp
rate setting is displayed and set in units of kilogauss/sec (or Tesla/
sec) as show below. The allowable range is defined by the setting of
the coil constant and the allowable range of the ramp rate in terms
of current as specified on page 7.
The Model 420 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 420 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.
3.3.2 Ramping in Manual Mode
The two keys labeled as
0$18$/&21752/
and control the
ramping function in manual mode. If the is pressed and becomes
illuminated, the Model 420 will ramp up at the ramp rate setting. The
ramping may be paused by pressing the
key again (or by pressing
5$033$86(
) to deactivate the manual up mode. Once deactivated, the
5$033$86(
key will become illuminated indicating that the PAUSED
mode has been entered.
$ 5DPS5DWH$VHF
9V
N* 5DPS5DWHN*VHF
9V