BK Precision 1651A, Инструкция по эксплуатации

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18
OPERATING INSTRUCTIONS___________________________________________________________________________
Constant Voltage/Constant Current Characteristic
The working characteristic of this power supply is called
a constant voltage/constant current automatic crossover
type. This permits continuous transition from constant
current to constant voltage modes in response to the load
change. The intersection of constant voltage and constant
current modes is called the crossover point. Fig. 7 shows
the relationship between this crossover point and the load.
For example, if the load is such that the power supply is
operating in the constant voltage mode, a regulated output
voltage is provided. The output voltage remains constant as
the load increases, up until the point where the preset
current limit is reached. At that point, the output current
becomes constant and the output voltage drops in
proportion to further increases in load. The crossover point
is indicated by the front panel LED indicators. The
crossover point is reached when the
CONSTANT
CURRENT
indicator comes on.
Similarly, crossover from the constant current to the
constant voltage mode automatically occurs from a
decrease in load. A good example of this would be seen
when charging a 12-volt battery. Initially, the open circuit
voltage of the power supply may be preset for 13.8 volts. A
low battery will place a heavy load on the supply and it will
operate in the constant current mode, which may be
adjusted for a 0.5 amp charging rate. As the battery
becomes charged, and its voltage approaches 13.8 volts, its
load decreases to the point where it no longer demands the
full 0.5 amp charging rate. This is the crossover point
where the power supply goes into the constant voltage
mode.
Figure 7. Constant voltage/constant current characteristic.
SERIES TRACKING OPERATION
When the series tracking mode of operation is selected, the
positive (red) terminal of the
“B”
supply output is internally
connected to the negative (black) terminal of the
“A”
supply.
This allows the power supply to be used as a single 0-to-48
volt power supply simply by using the negative (black)
terminal of the
“B”
supply and the positive (red) terminal of
the
“A”
supply.