KEPCO BHK-MG 200W (Full Rack) Series - Manual (Page 80)

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BHK-MG (OPR) 022014
FIGURE 3-10. ANALOG PROGRAMMING OF OUTPUT CURRENT (CURRENT MODE)
OR CURRENT LIMIT (VOLTAGE MODE) USING RESISTANCE
For either voltage programming or current programming, the external resistor R
EXT
connected
across terminals 6 and 8 of VOLTAGE PROG terminal strip TB2 or CURRENT PROG. terminal
strip TB3 functions as a feedback resistor for the internal uncommitted amplifier dedicated to
voltage or current programming. This uncommitted amplifier is configured to amplify and invert
the +10V reference applied via terminals 4 and 6 of TB2 or TB3. The output of the uncommitted
amplifier is applied via terminals 8 and 9 of TB2 or TB3 to a summing network at the input of the
summing and correction amplifier. For voltage programming, the other input to the summing and
correction amplifier, DP (V), is from the voltage portion of the digital programming circuitry
(either from the keypad or the GPIB bus). For current programming, the other input to the sum-
ming and correction amplifier, DP (C), is from the current portion of the digital programming cir-
cuitry (either from the keypad or the GPIB bus).
TABLE 3-10. FEEDBACK RESISTOR AND CURRENT SENSING RESISTOR VALUES
RESISTOR SCALE BHK 500-0.4MG BHK 1000-0.2MG BHK 2000-0.1MB
Voltage Feedback Resistor R 500K* 1000K* 2000K*
Current Sensing Resistor Rs HIGH CURRENT 0.0025K* 0.005K* 0.010K*
LOW CURRENT 0.025K* 0.05K* 0.10K*
* All resistors are 1% tolerance.