THORLABS LCC25, Руководство по эксплуатации

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Liquid Crystal Controller
18828-D02 Rev F, Sept 23, 2011 Page 8 www.thorlabs.com
Setting the Output
Output Mode has three selections. Pressing the OUTPUT MODE key will toggle through
each mode. The selected mode will be indicated in the bottom right of the LCD display.
The sequence is as follows: Voltage 1, Voltage 2, and Modulation. To activate the output,
press the OUTPUT ENABLE button. When active, the LED indicator next to the
OUTPUT BNC connector will be lit.
The supported modes are:
•
Voltage 1:
The output signal will be a 2 kHz
square wave with an RMS voltage level equal
to the value set by Voltage 1
•
Voltage 2:
The output signal will be a 2 kHz
square wave with an RMS voltage level equal
to the value set by Voltage 2.
•
Modulation:
The output signal will be a 2 kHz
square wave at an RMS voltage level
switching between the value currently set for
Voltage 1 and the value set for Voltage 2 at the
currently selected frequency.
Internal Modulation Frequency
The LCC25 has internal modulation frequency adjustable from 0.5 to 150 Hz. To use the
internal modulation, the LED next to the EXT INPUT BNC connect should be off. If it is
lit, press the INT/EXT key disabling the LED indicator. To adjust the modulation
frequency, push the FREQ key and adjust the knob to the desired output.
External Modulation Frequency
The LCC25 can be modulated by an external input. The modulation frequency device is
connected to the EXT INPUT BNC. The input signal can be any waveform with a
frequency from 0.5 to 500 Hz, and any duty cycle, but must be 0 and 5 Volts to trigger
the flip. The output from the LCC25 will be modulated based on the input frequency with
Voltage 1 being the high and Voltage 2 being the low.
To select the external modulation, the LED next to the EXT INPUT BNC connector
should be on. If it is not lit, press the INT/EXT key enabling the LED indicator. When the
external input is enabled, the top right of LCD will display EXT and bottom right will
switch to the modulation square -wave symbol (same as modulation is shown above.