2-6
MAT 6V/15V/25V/36V/ 022300
Keep the Power Module grounded when connected to an AC power source.
2.6.2
DC (OUTPUT) GROUNDING
DC output connections are those between the Power Module and the load, including remote
sensing connections if necessary. Despite precautions to eliminate noise such as shielding and
twisted wire-pairs, output connections may pick up radiated noise of a wide frequency. To mini-
mize such undesired effects, one side of the Power Module output/load should be grounded.
Successful D.C. grounding depends on careful analysis of the system operation. However here,
only general guide lines are provided. One of the major points, is to avoid ground loops. Ground
loops are created when two or more points of different ground potentials in the output circuit are
grounded. A noise voltage is developed that is superimposed on the load (output potential). A
way to avoid ground loops is to investigate for points of resistance to ground. Differences in
ground potential can be avoided if the output circuit is completely isolated. A single point is then
selected along the Power Module output circuit and returned to ground with a single wire. This
method is dependent on the specific application.
The MAT Power Modules are designed with Power Isolation relays that comply with MATE
(Modular Automated Test Equipment) Test Module Adapter requirements. Each output is fully
isolated from other outputs and from ground.
2.6.3
POWER MODULE TO LOAD INTERFACE
The general function of a voltage or current stabilized Power Module is to deliver rated output to
the load. The load may be fixed or variable; resistive, capacitive, or inductive; and may be
located close to or far away from the Power Module. The Power Module is designed for varied
applications. The aim of the following paragraphs is to instruct the user in the interface of the
Power Module to the load.
The perfect interface between a Power Module and load insures optimum performance. To
approach this state of operation, one must be familiar with certain requirements, such as inter-
connection guidelines, Ohm's Law and ac theory.
Load Wire Selection - A stabilized dc Power Module is not an ideal voltage or current source
with zero output impedance (voltage mode) or infinite output impedance (current mode): All volt-
age sources have some amount of impedance which increases with frequency and all current
sources have impedance which decreases with frequency. (See FIG. 2-4).
WARNING
