Figure 16-16. Blackout Stop and Marker Light
Figure 16-17. Military Composite Light.
tank-automotive vehicles is of this type. The active ir
and in the near-infrared region. The light intensification
system has the disadvantage of being detectable by an
system is characterized usually by its relatively small size
enemy equipped with ir detectors operating in the same
and is less complex than active systems because of the
range. For this reason, the active ir equipment is
elimination of transmitting hardware.
expected to be phased out completely and replaced by
disadvantage of this system Is that, like normal viewing,
range and performance depend on atmospheric
b. Passive System. A passive ir system cannot be
(2) The far-infrared ir systems operate by
detected or disabled by methods that are effective
utilizing light wavelengths that operate at the far end of
against active systems. Furthermore, most natural
objects radiate In the ir region, making a passive system
transmitted fairly well by the atmosphere, except in
very attractive. There are basically two types of passive
extreme humidity or rain. These systems utilize the
ir systems: light intensification, and far-infrared.
natural radiation from a given object to provide the power
by which the object is detected. Systems of this type can
(1) Light intensification systems are expected
be highly sensitive and have been designed to detect
to eventually replace the present active ir systems for
even the shadow left by an object removed from its
tank-automotive applications. In the light intensification
surroundings. These are receiving much attention in
system, images formed by the ambient light from
target location systems. A disadvantage at the present
starlight or moonlight are intensified by Image converter-
time is the large size of the equipment compared to the
type tubes. The Image converter tubes have a high
light intensity systems.
detective photo-cathode sensitivity in the visible
Section III. COMMERCIAL VEHICLE LIGHTING
to be shut off automatically after the turn is completed by
16-13. Turn Signal System.
the action of the canceling cam.
a. General. Vehicles that operate on any public
c. Switch Wiring and Electrical Operation.
roads in the United States must be equipped with turn
signals that indicate a left or right turn by providing a
(1) A wiring diagram for a typical turn signal
flashing light signal at the front and rear of the vehicle.
switch is shown in figure 16-19.
b. Control Switch (Fig. 16-18). The turn signal
switch is located on the steering column. It is designed