7
hivolt.de
GmbH & Co. KG
Oehleckerring 40
y
D-22419 Hamburg
y
+49 40 53 71 22 80
y
+49 40 53 71 22 99
y
y
http://www.hivolt.de
3.2
Control Voltage Input
The control voltage input (IN) is connected to a differential amplifier to
suppress common mode voltages between the external signal source and
the amplifier. Two jumpers (W1, W2) are provided on each amplifier
module HA05B2 in order to adapt the control voltage input to the signal
source.
W1 connects the input signal reference via 10
Ω
to the amplifier signal
ground. W2 adjusts the amplifier gain to the output impedance of the
signal source.
W1
1-2 Common mode voltage / Noise <1 V
RMS
or floating signal source
Default
2-3 Common mode voltage / Noise 1...4 V
RMS
W2
1-2 Output impedance of signal source <1
Ω
Default
2-3 Output impedance of signal source 50
Ω
Alternatively, the control voltage can be generated by means of a 10-
turn potentiometer (SETPOINT). The potentiometer supplies –10 V at the
CCW end position (0) and +10 V at the CW end position (10). Zero
position is at 5. Switching between internal and external control voltage
is achieved by a front panel switch (MAN / REM).
3.3
Measuring Circuits / Monitor Outputs
Two monitor outputs (V-MON / I-MON) provide actual values of output voltage and output
current, both of which are normalized to ±10 V. The monitor outputs receive their signal through
a compensated voltage divider. Current measurement takes place differentially across a sense
resistor in the output line. Due to differential measurement, a certain drift of the measured
output current over temperature and output voltage is inevitable (refer to technical
specifications).
If the INHIB-input is active, then an appreciable current flows through the sense resistor. This
current is shown by I-MON even though it does not flow from the output (The current flows into
the inhibit semiconductor switch). This value is masked out in the signal to the DVM.
The monitor outputs are buffered and short-circuit-proof. They can drive capacitive loads
(coaxial cable). They are not designed to drive terminated cables (50/75
Ω
), and they should
not be short circuited during normal operation. Load impedance
4 k
Ω
.
