THORLABS IP250-BV, Руководство пользователя

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IP250-BV Blue Laser Diode Controller Chapter 2: Setup and Operation
Rev F, October 24, 2017 Page 5
While operating in APC Mode, if the power is adjusted to its maximum limit then
the injection current will not increase even though the potentiometer has more
adjustment.
2.2.2. Automatic Constant Power Control (APC)
Photodiode feedback current is required in APC Mode.
1. Set JMP2 to “APC” for constant current operation. JMP2 is located on the
left side of the unit. Always disable the laser driver prior to changing
modes.
2. Apply power to the unit.
3. Using a digital multimeter measure the ILIM Test point with respect to the
TP GND Test point (all measurements will be with respect to TP GND).
Adjust the ILIM ADJ potentiometer to the maximum laser current limit.
The transfer function is 1 V = 1 A, with a maximum adjustment of
approximately 0.250 V or 250 mA.
When operating in APC the ILIM (current limit) function is still active if the
laser current reaches the limit point.
4. Measure the PLIM Test point and adjust the PLIM ADJ pot for the
maximum MPD current expected. The transfer function is 1 V= 1 mA, with
a maximum adjustment of 2.5 V or 2.5 mA.
5. The P/I ADJ Pot will allow adjustment of the monitor photodiode current
from 5 uA to the PLIM set point or 2 mA max. When turning on a laser for
the first time it is suggested that this pot be set fully counterclockwise.
6. Press and release the ENABLE switch.
7. The green LD ON indicator will turn ON. If the ALARM indicator turns ON
see “Alarms and Troubleshooting” below. If the I LIMIT indicator turns ON
immediately press the ENABLE switch and refer to “Alarms and
Troubleshooting”.
8. Adjust the P/I ADJ potentiometer clockwise to increase the MPD current.
The IPD Test point provides an analog read back of the actual MPD
current, 1 V = 1 mA.
9. Pressing the ENABLE switch while the laser is operating will turn off the
laser current.
While operating in APC Mode, if the power is adjusted to its maximum limit then
the injection current will not increase even though the potentiometer has more
adjustment.
If the PLIM is set to a value that requires a higher level of drive current than ILIM
is set to, the I LIMIT indicator will turn ON and the unit will operate in constant
current at the current limit level.