KEPCO BHK-MG 200W (Full Rack) Series - Manual (Page 93)

BHK-MG (OPR) 022014
3-49
3.6.5.1 VOLTAGE MODE
With the power supply in voltage mode (see Figure 3-17) and the digitally programmed output
voltage at zero, varying the external current source from 0 to 1mA causes the output voltage of
the power supply to vary linearly from 0 to Eomax with a slope of (Eomax) volts per mA. The fol-
lowing equations give the output voltage as determined by the external current source I
EXT
.
ANALOG PROGRAMMING, DIGITAL PROGRAMMING = 0:
Eo = (–1)I
EXT
x (10K) x (–1) (10K/10K) x (–1) (R/10K)
= –(R) x I
EXT
(V d-c)
where
R = Internal feedback resistance equal to correction resistance (K-ohms), determined by
Model (see Table 3-10).
I
EXT
= External current source. This source can be either a d-c source or a function generator
with an internal bias delivering a constant current. If the bias is not available from the
function generator, use the digital programming feature of the BHK-MG to provide
proper bias to avoid clipping waveform at the output of the power supply.
ANALOG PROGRAMMING COMBINED WITH DIGITAL PROGRAMMING:
Eo = –(R x I
EXT
) – Eout
DP
(V d-c)
where
Eout
DP
= Output voltage programmed digitally (from either local keypad or remote GPIB bus)
(See above for definitions of R and V
EXT
.)
3.6.5.2 CURRENT MODE
With the power supply in current mode (see Figure 3-18) and the digitally programmed output
voltage at zero, varying the external current source from 0 to 1mA causes the output current of
the power supply to vary linearly from 0 to Iomax with a slope of (Iomax) mA per mA. The follow-
ing equations give the output current as determined by the external current source I
EXT
.
ANALOG PROGRAMMING, DIGITAL PROGRAMMING = 0:
Io =
[ (–1) I
EXT
x (10K) x (–1) (1K/10K) x (–1) (1K/1K) ]/Rs
= –(1/Rs) x I
EXT
(mA d-c)
where
Rs =Internal shunt resistance (K-ohms), determined by Model (see Table 3-10).
(See above for definition of V
EXT
.)
ANALOG PROGRAMMING COMBINED WITH DIGITAL PROGRAMMING:
Io = –(1/Rs) x I
EXT
– Iout
DP
(mA d-c)
where
Iout
DP
= Output current programmed digitally (from either local keypad or remote GPIB bus)
(See above for definitions of Rs and I
EXT
.)