Lambda SRS SR475, Руководство по эксплуатации

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1 – 8 Operation
and help them to run at a comfortable temperature, particularly in a
warm laboratory environment.
An internal thermal sensor will trip o
ff
if the shutter head overheats.
In this case, the head will declare a fault and go to the Standby state.
1.2.3 Grounding considerations
For reliable operation of a SR475 or SR476, it is essential that the
shield of the shutter cable is properly grounded.
Inside the shutter head, there is an electrical connection between its
chassis (case) and the shield of the cable. If the chassis of the shutter
head is electrically connected to earth ground, for example by way
of attachment to a grounded optical table, then the shield will be
grounded as well.
SRS shutter controllers, such as the SR470 Shutter Controller and
the SR474 Four-Channel Shutter Driver, provide optional internal
grounding of the shutter cable shield. If a shutter case is prop-
erly grounded and thereby providing a suitable ground to the cable
shield, it may be desirable to disconnect the shield-ground connec-
tion within the controller; consult that instrument’s operation man-
ual for details.
Apart from the cable shield, the shutter cable uses a separate “signal
ground” as one of the power supply lines. This ground is normally
isolated from the shutter case and cable shield. Under certain cir-
cumstances it may be desirable (for the control of ground loops,
for example) to establish an electrical connection between the signal
ground and the cable shield. To do so, unplug the shutter head and
solder a jumper wire across location J11 on the circuit board. To ac-
cess the circuit board, you will need to temporarily remove the outer
case, which is held on by four screws.
1.3 Optical alignment
The SR475 and SR476 Laser Shutters are designed for easy alignment.
The clear aperture of the SR475 is aperture of 0.120” (3 mm), and the
clear aperture of the SR476 is 0.040” (1 mm). The laser beam may
enter the shutter head from either side, but there is less potential for
leakage of indirect scattered light if the beam enters from the side
marked “Front” in Fig. 1.3.
SRS shutter controllers incorporate an “Align” mode that chops the
shutter open and closed at a rate of 1 Hz to assist with manual
alignment. A similar chopping function is also directly built into the
shutter head firmware, and can be enabled over the remote interface.
SR475 and SR476 Laser Shutters