THORLABS IP250-BV, Руководство пользователя

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IP250-BV Blue Laser Diode Controller Chapter 2: Setup and Operation
Page 6 10713-D02
If the Photodiode is connected incorrectly or the connection is opened, the I LIMIT
indicator will turn ON and the unit will operate in constant current at the current
limit level.
2.2.3. Analog Modulation
The amplitude of the laser injection current can be varied over time by connecting
a signal generator to the BNC connector J3 on the IP250-BV. It is recommended
that the unit be configured to operate in ACC mode whenever analog modulation
is used.
J3 can also be used as a remote analog input, allowing the user to program the
laser injection current from 0 to 250 mA by applying a 0 to 10 VDC signal. The
transfer function being 25 mA per 1 V.
The P/I ADJ pot must be set fully counterclockwise prior to using this input.
For 100% depth of modulation set the P/I ADJ pot fully counterclockwise and apply
a sine wave input to J3. The peak-to-peak amplitude must equal ILIM / 0.025 and
a DC offset equal to 0.5 of the amplitude must be applied (the signal should always
be above 0 V).
The depth of modulation can be decreased by increasing the P/I ADJ pot to provide
a DC current offset, and then adjusting the peak-to-peak amplitude to stay within
the ILIM range. The ILIM circuit will limit the average current to the ILIM setting
and the I LIMIT indicator will turn on when the average current exceeds the ILIM
setting.
The ILD Test point will provide the average current level when modulating.