KEPCO BOP-HV - Manual (Page 34)

3-8
BOPHV112211
3) Turn the A-C POWER switch “OFF” and set the BOP MODE switch to the CURRENT posi-
tion and the BIPOLAR CURRENT CONTROL switch to “ON.” Reinstall the short-circuit
across the output terminals.
4) Turn the A-C POWER switch “ON” and adjust the BIPOLAR CURRENT CONTROL to zero
output current.
5) Turn the A-C POWER switch “OFF,” disconnect the short-circuit, and connect the load.
6) Turn A-C POWER switch “ON” again and adjust the required operating current by means
of the BIPOLAR CURRENT CONTROL as required.
NOTE: If the output current or output voltage exceeds the programmed limit values at any
time, the I
O
MODE light will go OFF and the corresponding “limit light” (CURRENT
LIMIT LIGHT for current limit or VOLTAGE LIMIT LIGHT for voltage limit) will go ON.
By removing the limit condition – decreasing the output current for current limit or
decreasing the value of the load for voltage limit, the unit will return to the current mode
of operation and the lights will be reset to the initial status.
3.3 BOP OPERATION WITH REMOTE CONTROL OF THE VOLTAGE CONTROL CHANNEL
As described in a previous paragraph (PAR. 3.2.1) the BOP d-c output potential can be con-
trolled within its specified range by means of the BIPOLAR VOLTAGE CONTROL, with the
BIPOLAR VOLTAGE CONTROL SWITCH in the ON position. Since the E
O
PRE-AMP, with the
built-in feedback and input resistors, has a gain of one, and the E
O
BIPOLAR AMPS have
respective gains of 50 (BOP 500M) and 100 (BOP 1000M), a d-c input signal of zero to (±)10V
will control the BOP output through its specified range. In the local (front panel) control mode,
the d-c control potential is applied via the BIPOLAR VOLTAGE CONTROL.
3.3.1 REMOTE D-C OUTPUT VOLTAGE CONTROL BY RESISTANCE
A) As shown in FIG. 3-7, this control method can be performed remotely by setting the BIPO-
LAR VOLTAGE CONTROL SWITCH to the OFF position and by connecting a 10K ohm
external resistor and a 20K ohm external potentiometer as shown in Figure 3-7.
By adjusting the remote external potentiometer, the BOP unit will receive an input voltage
signal ranging from –10 to +10 Volts that corresponds to a generated output voltage rang-
ing from –E
Omax
to +E
Omax
.
B) Two terminal resistance control of the d-c output voltage (for example, by means of a
Decade Box) can be exercised as shown in FIG. 3-8.
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.
The E
O
PRE-AMP functions here as an inverter. Its output can be expressed by the equa-
tion:
Rf = External Decade Resistor
Ri = External Input Resistor
EO (PRE-AMP) = – EREF (
Rf
Ri
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