Figure 2-5. Scan drive system, waveforms.

TM 11-6720-242-35

Figure 2-5. Scan drive system, waveforms.

2-13. Functioning of Annotation Pulse Circuit

numeric or binary information pertinent to the aircraft

mission. The data generated in the adas equipment of

a. The function of the annotation pulse circuit (fig.

the aircraft is transmitted to the recording head

2-10) is to supply aircraft equipment with a pulse that

assembly (rha) located in the body. The capping blade,

will coordinate the timing of the aircraft equipment with

activated by the capping cam (fig. 2-6), blocks off part

the camera operation. The annotation pulse circuit

of the variable slit (fig. 2-13) just before the film stops

converts the pulse initiated by the puck switch (para 2-

advancing, thus leaving a portion of film unexposed.

15) to a 6 + 1.5 volts, 500 + 250 microseconds isolated

When film advance stops, the adas pressure plate

pulse.

clamps the film (para. 2-3a). The coded information

b. When Q2 is turned on, as described in

appearing on the rha, is then projected by a lens and

paragraph 2-11, capacitor C2 charges up for the length

mirror assembly and photographed on the unexposed

of time that Q2 is turned on and together with the

portion of the film:

primary winding of transformer T1 furnishes the duration

b. The adas is not functionally a part of the

of the pulse. The secondary winding of transformer T1

camera, but is identified with the camera to the extent

isolates and provides the shape and width of the pulse.

that the lens, the mirror assembly and the rha is housed

VR1 clips the pulse at an amplitude of 6 + 1.5 volts and

in the body. A v/h reference voltage for the adas

CR1 prevents any back voltage. This output pulse

aircraft equipment is applied through V/H SEL switch

interfaces with the data annotation system being used in

3S3, located in the control panel.

the aircraft and provides the command necessary for

the recording head assembly (rha) display. The data

2-15. Functioning of Puck and End of Film

annotation system being utilized by the aircraft would be

Switches

either the AN/ AYA-5 Bowmar or the AN/AYA-10 Hiller

annotation systems.

(figs. 6-11 and 6-12)

a. Puck Switch. The puck switch 1SI is located in

2-14. Functioning of Auxiliary Data

the body (43, fig. 3-4 (2)) and is actuated by the timing

Annotation System

cam (fig. 2-6). It is momentarily closed to ground twice

during each revolu-

a. The function of the auxiliary data annotation

system (adas) is to record on the film alph-

2-13