American Magnetics 4Q12125PS-430 High Stability Integrated Power Supply System - Manual (Page 21)

Rev. 5 3
Introduction
General Description
more detail in section A.6.2 on page 151 of the Appendix. Contact AMI for
more information.
In addition to low LHe level, this input to the Power Supply System can be
used with other instrumentation as well. Other uses for this input include
faults from a cryocooler, temperature instrumentation, etc.
1.1.8 Model 4Q12125PS-430 General Description
A Model 430 Power Supply Programmer and two Model 4Q06125PS Power
Supplies are configured to make up the system designated as 4Q12125PS-
430. The Model 4Q06125PS is a 750 Watt, ±6 Volt, ±125 ampere, 4-
quadrant, voltage and current stabilized DC supply. Two Model
4Q06125PS Power Supplies are connected in a Master/Slave series
configuration to provide the rated voltage. The power supplies are
remotely controlled by the Model 430 Power Supply Programmer.
The Model 4Q12125PS-430 is a true 4-quadrant voltage and current power
supply capable of both sourcing and sinking
1
power smoothly through zero
to provide true ±voltage and ±current. It is ideal for controlling inductive
loads such as large magnets or motors.
The power supplies are controlled by a ±10 Vdc remote analog signal
supplied by the Model 430 Programmer and applied to the power supply
analog inputs. Programming and control of the current loop (composed of
the magnet, power supplies, and Model 430 Programmer zero flux device),
is provided by a Model 430 ramp-generated current reference with
parameters as set by the user in the Model 430. The Model 430 compares
the measured current (via the zero flux device) with the current reference
to provide precise closed-loop control of the actual current.
The power supply units are operated in voltage-voltage 2 programming
mode, with the Model 430 Programmer output scaled to operate the power
supply units over their available voltage output range. The Programmer
signal will continually adjust the power supply output voltage to
automatically regulate the power supply current; precise linear power
supply current control will result as long as the system voltage and
current demand do not exceed the total power supply rating or load
limiting parameters.
1. The power supply is operating as a source if the current direction and voltage polar-
ity are the same (i.e., the situation that would exist when supplying a resistive load).
If the voltage polarity and current direction are opposite, the supply is operating as
a sink and energy is being absorbed or returned to the “ac-line”.
2. Voltage reference controlling voltage output.