Theory Of Operation - Mechanical; Figure 3-1 Actuator And Proximity Sensors - Will Burt Night Scan Chief Installation, Operation & Maintenance Manual

3.1 THEORY OF OPERATION – MECHANICAL
Night Scan Chief – Mast
The Night Scan Chief operates using a DC powered actuator to drive the mast from nest to 90 degrees.
When at 90 degrees, a magnetic sensor detects the actuator position and prevents further driving of the
actuator. The sensor also notifies the operator through the Remote Control(s) that certain RCP functions
are available. The compressor assembly included in the base will receive power and pressurize the mast
when the up button is depressed. If, at any time, power to the unit is lost, the exhaust valve opens,
exhausting all air from the mast.
As the mast is nested, the base control looks for indication from a magnetic switch that the mast has fully
retracted and may be safely restored to its fully nested (horizontal) position. If the "double click"
unattended stow sequence was not used, the RCP will begin the autostow sequence to insure that the
RCP is properly positioned for engagement with the saddle. If the autostow "double click" sequence was
used, the RCP will have properly positioned itself as the mast descended prior to horizontal nesting into
the saddle.
RCP
The RCP provides pan and tilt functions upon command from the Remote Control(s). DC powered gear
motors turn the shafts until an opaque flag in the assembly reaches a photo interrupter. At this time, the
LED on the Remote Control(s) for that direction of travel will go out, indicating that a limit has been
reached in that direction.
Revision 1
PROXIMITY
SWITCHES
Figure 3-1 Actuator and Proximity Sensors
ACTUATOR
Night Scan Chief
3-2