TM 5-6675-320-14
When a pen is installed in a pen stable, it causes the pen stable switch to close,
which provides a low input signal to PCA A5 via PCA A6. This low signal indicates
that there is a pen in that particular pen stable .
P e n - i n - a r m s w i t c h i n d i c a t e s i f
there is a pen in the arm via a similar low signal.
4-3.2.5 Pen Drive Circuits.
Accept pen position data from PCA A5 and drive the
plotter chart pens along the X- and Y-axes.
A series of drive wires are utilized to
move the pens, controlled by the pen drive circuits.
T h e p e n d r i v e c i r c u i t s i n c l u d e t h e f o l l o w i n g f u n c t i o n a l u n i t s:
Motor driver PCA A8
Pen solenoid
Transistor driver PCA A12
X- and Y-drive motors
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