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Laser Controller
Product Manuals - https://www.vescent.com/manuals/
panel adjustment of the temperature set-point, while the stage 1 temperature set-point is a side-
panel adjustment. Additionally, the front panel TEMP SERVO INPUT adjusts the stage 2 set-point while
stage 1 does not have an equivalent function. Stage 2 is accessed in the middle of the side-panel,
while stage 1 is near the back of the side panel. Typically, stage 2 is used to control the laser
temperature and stage 1 is used to control the temperature surrounding stage 2. In this way
temperature gradients between the laser diode and the thermistor measuring the laser temperature
are stabilized and temperature changes caused by room temperature drift are greatly reduced.
Laser Controller Serial Numbers above 2675, inclusive; Temperature Control Board Serial
Numbers above 6987, inclusive
To reset the temperature loop parameters to the factory settings for a D2-100-DBR Laser:
Set the dip switches to the configuration shown in
and
.
1.
Measure the resistance across GND5 and probe point GAIN1. Set this resistance to between 3.0
2.
kΩ and 3.2 kΩ by adjusting trimpot PROPGAIN1.
Measure the resistance across GND5 and probe point GAIN2. Set this resistance to between 1.2
3.
kΩ and 1.4 kΩ by adjusting trimpot PROPGAIN2.
Fig. 4: Factory settings of T2 (left) and T1 (right) poles for units with S/N 2675 or
higher (PCBs with S/N 6987 and higher)
T2
Prop.
On
0.047
s
0.1 s
0.22 s
0.47
s
1.0 s 2.2 s
4.7
s
On
x
x
Off x
x
x
x
x
x
T2
Diff.
On
0.01 s
0.022
s
0.047
s
0.1 s
0.22
s
0.47
s
1.0
s
On x
x
x
Off
x
x
x
x
x
Tab. 3: Factory settings of T2 Proportional poles (first DIP
