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Doc 12536-D03 Rev D 9/19/2005
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of
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Section 6: Getting Started Quickly
This section is provided for those interested in getting the MC1000A up and running quickly as a basic optical chopper.
The more advanced features are described in detail in the following sections.
6.1 Setup
1. Carefully unpack the MC1000A controller, optical head, and accessories. See section 4 for a complete list of
parts. If any of the items appear damaged or missing, do not use the MC1000A. Call Thorlabs, or email
[email protected] and arrange for a replacement.
2. Remove the 3 mounting screws and lock washers from the chopper blade hub using the 1/16” hex key (provided).
3. Unpack the 10-slot blade and install onto chopper blade hub using the 3 screws and washers removed in the
previous step. Tighten the screws securely with the hex wrench.
4. Attach the modular cord into the jack labeled ‘OPTICAL HEAD’ on the back of the MC1000A controller and plug
the other end into modular jack on the optical head.
5. Mount the optical head on a sturdy surface and check that the blade can spin free of any obstruction.
6. Attach the AC line cord to the MC1000A and plug into an AC outlet.
Note: the MC1000A can be operated from 100/115VAC or 230VAC. A voltage selector switch is located inside of the
MC1000A controller. If you are not sure what operating voltage your unit is set to, proceed immediately to Section 5.0 for
instructions on setting the operating voltage.
6.2 Internal Reference Operating Mode
This MC1000A is most commonly used in the internal reference mode. The chopping speed is set by the internal crystal-
stabilized frequency synthesizer.
1. Turn the MC1000A power on. The LED display will go through a startup sequence: first, all of the display
segments and LED’s are lit, then the firmware rev level is displayed, followed by the current blade setting.
2. The display should show “b 10” for the 10-slot blade. If not, press the ‘
▲
’ key until the “b 10” message is
displayed and then release the button. The unit will time out after a second or two and go into a standby mode
with the display showing “oFF”. If you miss the timing of this, turn the power switch off then back on again to
return to this mode.
3. If the unit comes up in the EXTERNAL REFERENCE Mode (as indicated by the LED above the ‘EXT IN ENABLE’
key being lit), press the ‘EXT IN ENABLE’ key to turn it off and return to the internal reference mode.
4. The unit should be in a standby mode with “oFF” displayed on the front panel. Press any of the keys to start the
chopper motor.
5. To change the chopper speed, press the ‘
▲
’ or ‘
▼
’ keys until the desired speed is shown. Release the key and
the unit will adjust its speed and lock onto the set speed within a few seconds.
6.3 External Reference Mode
This mode is very similar to the internal reference mode except that the chopper blade is locked to a logic-level external
reference signal.
1. To enable external reference mode, attach a TTL or CMOS logic level reference signal to the ‘EXT REF INPUT’
BNC on the front panel and follow the above steps.
2. Press the ‘EXT IN ENABLE’ key to enable the external reference mode.
Note: If the chopper does not lock to the exactly frequency of the external signal check that the harmonic multiplier, N, is
set to 1 by pressing the ‘MODE’ key until the light under the ‘SET N’ LED is lit. The display should show a 1. If not, press
the ‘
▼
’ key until it reaches 1. Repeat his step for the sub-harmonic divider, D.
