KEPCO BOP-GL 1KW, Руководство оператора

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BOP-1K-GL 111315
2-13
The exact location of the “best” d-c ground point is entirely dependent upon the specific applica-
tion, and its selection requires a combination of analysis, good judgement and some amount of
empirical testing. If there is a choice in selecting either the OUTPUT or COMMON output termi-
nals of the power supply for the d-c ground point, both sides should be tried, and preference
given to the ground point producing the least noise. For single, isolated loads the d-c ground
point is often best located directly at one of the output terminals of the power supply; when
remote error sensing is employed, d-c ground may be established at the point of sense lead
attachment. In the specific case of an internally-grounded load, the d-c ground point is automat-
ically established at the load.
The output and common terminals of BOP power supplies are d-c isolated (“floating”) from the
chassis in order to permit the user maximum flexibility in selecting the best single point ground
location. Care must be taken in measuring the ripple and noise at the power supply: measuring
devices which are a-c line operated can often introduce additional ripple and noise into the cir-
cuit.
There is, unfortunately, no “best” method for interconnecting the load and power supply. Individ-
ual applications, location and nature of the load require careful analysis in each case. Ground-
ing a single point in the output circuit can be of great importance. It is hoped that the preceding
paragraphs will be of some assistance in most cases. For help in special applications or difficult
problems, consult directly with Kepco's Application Engineering Department.
2.5.3.1 GROUNDING NETWORK CONFIGURATION
When the output is floating there is a tendency for large changes in output voltage to affect the
digital programming section, possibly resulting in an erroneous output. Decoupling capacitors
from each of the two output terminals to the chassis via a terminal block link form a grounding
network. The grounding network is designed to reduce high frequency noise and ensure that the
digital programming section is not adversely affected by the dynamic swing of the output. The
power supply is shipped with the grounding network connected: a connection between terminals
TB1-4 (GND NET) and TB1-5 (GND). To disconnect the grounding network from the output,
remove the connection across TB1-4 and TB1-5.
2.5.4 POWER SUPPLY/LOAD INTERFACE
The general function of a voltage- or current-stabilized power supply is to deliver the rated out-
put quantities to the connected load. The load may have any conceivable characteristic: it may
be fixed or variable, it may have predominantly resistive, capacitive or inductive parameters; it
may be located very close to the power supply output terminals or it may be a considerable dis-
tance away. The perfect interface between a power supply and its load would mean that the
specified performance at the output terminals would be transferred without impairment to any
load, regardless of electrical characteristics or proximity to each other.
The stabilized d-c power supply is definitely not an ideal voltage or current source, and practical
interfaces definitely fall short of the ideal. All voltage-stabilized power supplies have a finite
source impedance which increases with frequency, and all current-stabilized power supplies
have a finite shunt impedance which decreases with frequency. The method of interface
between the power supply output and the load must, therefore, take into account not only the
size with regard to minimum voltage drop, but the configuration with regard to minimizing the
impedance introduced by practical interconnection techniques (wire, bus bars, etc.). The series
inductance of the load wire must be as small as possible as compared to the source inductance
of the power supply: although the error sensing connection to the load compensates for the d-c
voltage drop in the power leads, it cannot compensate for the undesirable output effects of the
power lead inductance. These lead impedances (both power and sensing leads) are especially