American Magnetics 03300PS-430-601 High Stability Integrated Power Supply System - Manual (Page 28)

10 Rev. 5
Introduction
Operating Characteristics
1.7 Operating Characteristics
The Model 430 Programmer has
been designed to perform with var-
ious power supplies to allow the
user the greatest degree of system
flexibility. The power supply and
Programmer combination are cate-
gorized by one of three forms: sin-
gle-quadrant, dual-quadrant, and
four-quadrant. For sake of clarity,
the term quadrant is defined as
one of four areas of a cartesian
coordinate system where the
abscissa is current and the ordi-
nate is voltage. Refer to Figure 1-4.
1.7.1 Dual-Quadrant Operation
In the Model 03300PS-430-601 dual-quadrant Power Supply system, an
energy absorber is added in series with the unipolar supply; this allows
stored magnetic energy to be converted to thermal energy, thereby
allowing much faster magnetic field reduction. This corresponds to
operation in quadrants 1 and 4 of Figure 1-4. The disadvantage to this
type of system is that energy is being dissipated in the energy absorbing
element whenever current is flowing. This loss is sometimes a significant
portion of the power required to operate the system.
The high-stability dual-quadrant precision current transducer-based
variation, depicted in Figure 1-6, typically increases the system stability
20
-20
200 -200
V
I
Positive Current
Flow Direction
Positive Voltage
Polarity
Positive Current
Flow Direction
Negative Voltage
Polarity
Negative Current
Flow Direction
Positive Voltage
Polarity
Negative Current
Flow Direction
Negative Voltage
Polarity
1 2
4 3
Figure 1-4. The Four Regions, or
Quadrants, of System Operation.
Magnet
Coil(s)
Persistent
Switch
(optional)
Misc. Line Losses
Model 420
Shunt
Energy
Absorber
V
Unipolar
Power Supply
Current
Figure 1-5. Dual-Quadrant System with Resistive Shunt
430