The solenoid is electrically controlled, and when
energized, it allows air pressure to be vented and
the ram air scoop opens.
CABIN AIRFLOW/TEMPERATURE
SENSOR
The cabin airflow/temperature sensor is a
flow sensor and a temperature sensor in a
single unit. The sensor is installed in the
cabin air inlet duct and provides electrical
signals to the ACS temperature/flow controller
based on air temperature and flow. The electrical
signals are used by the ACS temperature/
flow controller for automatic operation of
the cabin flow valve and cabin add heat
valve.
AUTOMATIC DRAIN VALVE
The automatic drain valve, located in the cabin
air supply duct, is open to drain moisture from
the supply duct. The valve closes when air pressure
is applied to the system.
CABIN DEFOG PLENUM
DISTRIBUTION VALVE
The cabin defog plenum distribution valve,
located in the cabin inlet duct, is a man-
ually controlled valve that divides the flow
of cabin inlet air between cabin cooling
and windshield defog. The valve contains
two movable, shaft-mounted cones that reg-
ulate airflow. Movement of one cone causes
an equal and opposite movement of the
other cone. This causes an increase in one
volume of air and a decrease in the other.
The valve is controlled by the cockpit-mounted
control handle and linkage, through the push-pull
control.
CONTROL HANDLE AND LINKAGE
The control handle and linkage allows the pilot
to set the cabin defog plenum distribution valve
to control the flow of windshield defog and cabin
3-14
cooling air. An electrical limit switch is installed
in the control handle housing. The switch is
activated when the handle is within 10 percent of
HIGH defog. When activated, the switch sends
a signal to the ACS temperature/flow controller
to increase the temperature of the defog air by
opening the cabin add heat valve.
PUSH-PULL CONTROL
The push-pull control connects the control
handle and linkage with the cabin defog plenum
distribution valve. Movement of the control
handle and linkage is transmitted to the cabin
defog plenum distribution valve by the push-pull
control.
SUIT/CABIN TEMPERATURE
CONTROL
The suit/cabin temp control contains two
dual section potentiometers. The potentiometers
have an outer shaft and control knob for
cabin temperature control and an inner shaft
and control knob for vent suit temperature
control. The cabin temperature control potenti-
ometer provides electrical signals to the ACS
temperature/flow controller for automatic
temperature control and directly controls the
position of the cabin add heat valve for manual
temperature control.
AUTOMATIC TEMPERATURE
CONTROL
Automatic temperature control is selected
by setting the ECS mode switch to AUTO.
In the auto mode, the pilot selects the cabin
temperature by adjusting the cabin knob
of the suit/cabin temp control. The ACS
temperature/flow controller produces a ref-
erence signal in relation to the setting selected
on the suit/cabin temp control. A control
circuit in the ACS temperature/flow controller
compares a signal from the temperature
sensing element of the cabin airflow/temper-
ature sensor with the reference signal and
modulates a control signal to the cabin add
