User guide

Rev. 5 53
Operation
Setup Menu : Load
The Current Limit setting can be used to limit the magnet current
to values lower than the Magnet Current Rating for testing or other
purposes (refer to Figure 3-12).
The value can be set by using either the numeric keypad per
section 3.3 on page 25 or the fine adjust knob (section 3.4 on
page 26). The Current Limit is specified as an absolute value, but if
the power supply is four quadrant, the Current Limit applies to
both the positive and the negative current direction (current limit
symmetry). The Model 430 Programmer will beep once and deny
the change if the user attempts to set the Current Limit below the
present Target Field Setpoint.
3.10.2.5 Calculate Magnet Inductance
This menu pick will automatically determine the inductance of the
load magnet. The inductance is determined by measuring the
voltage developed across the magnet (V
m
) with a fixed di/dt
(current rate-of-change in A/sec) passed through the load. The
function must be executed with the magnet ramping.
1
After the
function is executed by pressing the
ENTER key, the algorithm will
wait for 2 seconds to allow the current charge rate to stabilize and
1. Refer to section 3.12.3 on page 76.
Figure 3-12. Example Current Limit Setup
+00.00 A — Magnet Inductance (H)
+0.00 Vs Calculate