KEPCO BHK 1000-0.2MG Operator'S Manual Download

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2-10

BHK-MG (OPR) 032816

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
important if the load is a) constantly modulated or step-programmed, b) has primarily reactive
characteristics, or c) where the dynamic output response of the power supply is critical to load
performance.

2.7.4.1

CABLE RECOMMENDATIONS

For power cables (positive and negative) No. 20 or 22 AWG stranded wire is recommended for
each (these sizes fit the plugs supplied for the front panel output connections). The wire insula-
tion must be rated for nominal voltage of the power supply (e.g., 500V for BHK 500-0.4MG). If a
float voltage is used, the wire insulation must be rated for the nominal voltage of the power sup-
ply plus the float voltage; the DC Isolation Voltage (see Table 1-2, under Output Characteristics)
defines the maximum float voltage allowed. For noisy environments, tied pair (adjacent wires
secured with cable ties) or twisted pair cables are recommended. It is recommended that cable
length not exceed 50 feet; for longer cable lengths, contact Kepco.

Remote sensing is used to accurately control voltage at the load rather than at the output termi-
nals of the power supply (local sensing) by compensating for voltage drop (0.5 V d-c per lead) in
the power cables. For sense cables (positive and negative) No. 22 AWG stranded wire is rec-
ommended for each. For noisy environments, tied pair or twisted pair cables are recommended.
It is recommended that cable length not exceed 50 feet; for longer cable lengths, contact Kepco.

2.7.5

LOAD CONNECTION - GENERAL

Load connections to the BHK-MG power supply are achieved via the rear output terminal strip
(TB1); (+) and (-) outputs are also available at jacks located on the front panel. Configuration of
the rear output terminal strip is facilitated by five types of links supplied with the unit:

•

2-terminal link: (qty 2)

•

3-terminal link: (qty 2)

•

4-terminal link: (qty 2)

•

5-terminal link: (qty 1)

•

6-terminal link: (qty 1)

These links are used to configure the power supply for local or remote sensing, slow or fast
mode, insertion of the grounding network, isolated (floating) output, and negative or positive
grounded output. The links allow many possible configurations using various combinations of
the configurable parameters noted above.

The BHK-MG power supply is shipped from the factory configured as follows (factory default
configuration): local sensing, grounding network connected, slow mode, output isolated from