Qioptiq DIV 20 Instruction Manual - page 6
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signal. The output impedance of the signal generator must be sufficiently low to
drive the input of the DIV 20 (see section 7. specifications). The input
impedance of the DIV 20 can be switched to 50
or to 600
. In the case of
narrow pulses combined with high repetition rates, we recommend choosing 50
for the input impedance. Make sure that the function generator also provides
50
output impedance. With the 50
connection, reflections in the connector
cable are avoided. Such reflections in the connector cable can cause faults in
the signal trigger. For the special version DIV 20 (600 Ohm) the input
impedance is fixed at 600 Ohm and the impedance switch is missing.
Additonal important remarks
Mistakes in the handling of the DIV 20 are preserved by the display of nearly all
operation modes via LEDs on the front panel. The red LEDs are of premium
importance. If the TEMP is on, then an overload condition or a fault in
connection is indicated. The red LEDs EXTERN indicate that the DIV 20 is set
for external control of the offset voltage (LED above the DC-offset knob is on )
and/or of the pulse voltage (LED above the pulse voltage knob is on).
The TEMP LED indicates an overload condition of the DIV 20. The flashing
LED indicates a current overload. To re-receive a signal voltage at the output
socket, either the pulse voltage has to be set to the minimum value or the
frequency has to be reduced. The frequency has to be reduced until the current
overload is switched off. Instead of the reduction of the pulse voltage, another
possible way to switch off the current overload, is to set the mode switch (S2) to
the LOW position. After switching the mode switch again to the HIGH position,
the signal voltage is again available on the output socket.
The constant shining TEMP LED indicates an thermal overload of the DIV 20
amplifier. If the LED is on, no voltage is supplied to the output socket for the
pulse voltage. After a recovery time of ~20 seconds, the output pulse voltage is
re-received automatically.
In the PULSE position of the mode switch (S2), the light intensity follows the
pattern of the input signal. Intermediate intensity levels (grey scales) cannot be
switched: the DIV 20 is a pure digital (on/off) driver.
The safety of the complete measurement system in which the DIV20 is
integrated, is the responsibility of the installer of the system.
5. Remote control
Pulse voltage and offset voltage can be controlled externally. This permits, for
instance, installing automatic temperature drift compensation or laser power
drift compensation. For external control, the 25-pin Sub-D Connector on the
back panel of the DIV 20 should be used (see chapter 10).