KEPCO BOP 5-20DL, Руководство оператора

Страница: 44 / 70

3-10
BOP 5-20DL 081915
3.4.2 REMOTE VOLTAGE CONTROL USING RESISTANCE (DECADE BOX)
Two-terminal resistance control of the d-c voltage (for example, by means of a Decade Box
(make-before-break type) or any variable resistance) can be exercised as shown in Figure 3-7.
The external switch (S1), connected across the (±) reference voltage, is used to pre-select
either positive or negative output by setting it to the applicable reference voltage polarity.
PREAMP “A” functions here as an inverter. Its output can be expressed by the equation:
E
O (PREAMP “A”)
= –E
ref
(R
f
/R
i
). where
R
f
= Decade Resistor.
R
i
= Ext. Input Resistor
The BOP output voltage will vary linearly with the change in decade resistance.
This programming system can be calibrated very accurately by setting the external Remote
Voltage Control (Decade) to zero, and adjusting for zero output volts using the screwdriver-
adjusted E
O
ZERO control while monitoring the BOP output with a digital voltmeter. The maxi-
mum output voltage is calibrated by making all or part of R
i
a rheostat and adjusting it with the
Remote Voltage Control at maximum resistance, to the maximum BOP output voltage.
FIGURE 3-7. REMOTE D-C OUTPUT VOLTAGE CONTROL USING TWO-TERMINAL RESISTANCE
(DECADE)
3043882
BOP VOLTAGE
CONTROL CHANNEL
PART OF
REAR PROGRAMMING CONNECTOR
+
22
28
C
+
VOLTAGE
CONTROL
VOLTAGE
PROGRAMMING
INPUT
10V
OFF
10V
ON
10K
10K
11
9
C
7
POWER
STAGE
NOTES:
1. Set MODE Switch to VOLTAGE.
2. Remote sensing shown (links removed). For local
sensing disconnect leads beteen S terminals and
load, then install links between COM and S
terminals and between OUT and S terminals.
3. Remove jumper between terminals (7) and (9) of
Rear Programming Connector.
COMMON
5
Eo ZERO
-
17
+
Eo COMP
AMP
ZERO
PREAMP
"A"
-
+
2.49K
DRIVER
G
A
T
E
COM
S
OUT
S
10K
LOAD
SIGNAL
GROUND
REMOVE
SENSING LINK
REMOVE
SENSING LINK
S1
POLARITY
SELECTOR
(EXT.)
0 - 2.5K
REMOTE VOLTAGE
CONTROL (EXT.)
R i (EXT.)
R f