Output Voltage Range; Current Limit Programming; External Resistance Programming Of Output Voltage; External Voltage Programming Of Output Voltage - KEPCO HSM 3.3-230 Operator's Manual

c) External Voltage Programming: When enabled via S2-3, this mode provides for output
voltage adjustment via an external voltage source (0-10V) connected between pins 18 and
19 (VPROG, -S) of the I/O connector (see Figure 3-2). This technique is useful when imple-
menting digital control of the power supply output voltage via a D/A converter; Kepco's
SN/SNR 488 programmers are ideally suited to these requirements.
FIGURE 3-1.
FIGURE 3-2.
3.4

OUTPUT VOLTAGE RANGE

The user may select the maximum programmable voltage, either high or low range, via S2
switch positions 1 and 2 (see Figure 2-1). This permits the user to trade adjustment range for
programming resolution; this is especially useful when used in conjunction with external voltage
programming (see PAR. 3.3) for precise output adjustment (±0.2%), or for limiting the maximum
programmable voltage. Operation of range selector is as follows:
a) High Range: This is the factory-set (default) mode; the maximum programmable output volt-
age is 110% of nominal VO for 3.3V through 28V models, 125% of nominal VO for 48V
model.
b) Low Range: When enabled via S2-1,2 the maximum programmable output voltage is equal
to the nominal output voltage V
age ranges do not change, the resolution for a given programming input increment increases
by 10% for 3.3V through 28V models, and by 25% for 48V model.
NOTE: When setting the programming range, both S2-1 and S2-2 must be set to the same
position; otherwise, the fault detector voltage window will be offset from the program-
ming value and will not operate properly.
3.5

CURRENT LIMIT PROGRAMMING

HSM power supplies provide two different methods for programming the output current limit
point: internal and external voltage. When using internal programming, the minimum program-
mable current limit is 50-60% of nominal, while external voltage programming permits adjust-
3-2

EXTERNAL RESISTANCE PROGRAMMING OF OUTPUT VOLTAGE

EXTERNAL VOLTAGE PROGRAMMING OF OUTPUT VOLTAGE

for all models; since the programming resistance and volt-
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HSMSERIES OPR 052912