User`s guide

Since you are considering
a transition to a new power
supply, you may want to take
advantage of some of the new
features/options by considering
something other than an
N672xA replacement model.
Please see the N67xxA User’s
Guide and datasheet for a
complete list of features and
options available in an
N67xxA MPS.
Safety Certification
662xA: These products are
Safety Class 1 instruments. They
comply with the requirements
of the Low Voltage Directive
73/23/EEC and the EMC
Directive 89/336/EEC and
carry the CE-marking
accordingly.
N67xxA: These products are
Safety Class 1 instruments.
They comply with the
European Low Voltage
Directive 73/23/EEC and
carry the CE-marking. This
product also complies with
the US and Canadian safety
standards for test and
measurement products.
Voltage, Current, and Power
The N672xA can produce all
combinations of voltage and
current that the 662xA is capable
of producing. The N672xA’s
voltage, current, and power
specifications are a superset
of the 662xA’s and in most
cases can produce up to
25% more power.
Output Ranges and Autoranging
The 662xA’s outputs are limited
to two ranges of voltage and
current. For example, the 40 W
Low Voltage output is limited
to 40 Watts or less within the
two “rectangular” ranges of
0-7 V/0-5 A and 0-20 V/0-2 A.
The N672xAs, however, can
produce any combination of
voltage and current within its
maximum voltage and current
specification as long as it falls
at or below its maximum power
rating
5
. For example, the 50 W
High Performance Autoranging
DC Power Module (N6751A),
which replaces the 40 W Low
and High Voltage outputs in
the 662xAs, can output any
combination of 50 Watts or
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The N6752A is the only exception to this
rule. It can produce 100 W from 12 V/8.33 A
to 50 V/2 A. Between 8.33 A and 10 A, the
N6752A’s output power derates from 100 W
to 85 W. Please see the 100 W Comparison
Graph in Appendix A for a graphical
representation of this.
less within 0-50 V/ 0-5 A.
Therefore, this module, at its
maximum voltage of 50 V can
output up to 1 A and at its
maximum current of 5 A can
output up to 10 V. This type
of operation is known as
“autoranging.” Please see
Appendix A for a graphical
representation of this example.
Protection Features
Overvoltage Protection
(OV or OVP)
On the 662xA models, the OV
trip point can be programmed
up to 23 V on any 40 W or 80 W
Low Voltage Output and up to
55 V on any 40 W or 80 W High
Voltage Output as well as the
25 W and 50 W precision out-
puts. The overvoltage protection
shorts the output by firing an
SCR crowbar and sets zero
volts and minimal current on
the output. The 662xA also has
a fixed overvoltage threshold
of approximately 120% of the
maximum rated output voltage
built into each output. When
an overvoltage occurs, the word
OVERVOLTAGE appears in the
front panel display and the OV
status bit is set for that output.
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Electrical