70
83503001 Rev G
6.5.
Resistive Programming of Output Voltage and Current Limit
For resistive programming, internal current sources, for Output Voltage and/or Output
Current control, supply 1mA current through external programming resistors connected
between J1-9 & 22 and J1-10 & 23. The voltage across the programming resistors is used
as a programming voltage for the power supply. Resistance of 0
5Kohm or 0
10Kohm can
be selected to program the Output Voltage and Output Current from zero to full scale.
A variable resistor can control the output over its entire range, or a combination of variable
resistor and series/parallel resistors can control the output over restricted portion of its
range.
Perform the following procedure to set the power supply to Resistive programming:
a) Turn the AC On/Off switch to Off.
b) Set setup switch SW1-1 to its UP position for output voltage external programming and
SW1-2 to its UP position for Output Current limit external programming.
c) Set SW1, position 3 to select the programming resistor range according to Table 6-4.
d) Set SW1-7 to its UP position for output voltage resistive programming and SW1-8 to its
UP position for Output Current limit resistive programming.
e) Connect a short between J1-8, J1-12 and J1-23 (refer to Table 4-4).
f)
Connect the programming resistors to the mating plug of J1 as shown in Fig.6-2.
g) Set the programming resistors to the desired resistance and turn the power supply ON.
Adjust the resistors to change the power supply output.
Notes:
SW1, positions 4, 5, 6 and 9 are not required for remote programming. Their
settings can be determined according to the application requirements.
The control circuits allow the user to set the Output Voltage and Output Current up
to 5% over the model-rated maximum value. The power supply will operate within
the extended range, however it is not recommended to operate the power supply
over its voltage and current rating and performance is not guaranteed.
To maintain the temperature stability specification of the power supply, the resistors
used for programming should be stable and low noise resistors, with temperature
coefficient of less than 50ppm.
When resistive programming is used, front panel and computer control (via serial
communication port) of Output Voltage and Current are disabled.
SW1-3 setting
Output Voltage programming
VPGM (J1-9)
Output Current programming
IPGM (J1-10)
UP
0-10Kohm
0-10Kohm
DOWN
0-5Kohm
0-5Kohm
Table 6-4: SW1-3 Setting and Programming Range
1
14
13
25
10
9
23
22
CURRENT LIMIT
PROGRAMMING
OUTPUT VOLTAGE
PROGRAMMING
J1 connector, rear panel view
Fig.6-2: Remote resistive programming
PROGRAMMING
RESISTOR
PROGRAMMING
RESISTOR
OPTIONAL SETS
LOWER LIMIT
OPTIONAL SETS
LOWER LIMIT
OPTIONAL SETS
UPPER LIMIT
OPTIONAL SETS
UPPER LIMIT
12
8