Section 1: Introduction
Bambi MAX Service Manual
– Models HL4000-HL9800 3
Operation of the valve motor is regulated by a controller located in a waterproof enclosure on the top of the
valve assembly. The controller receives power and a control signal from the aircraft via a three conductor
cable. The control signal is provided in the aircraft via a momentary push button and relay.
Valve position feedback to the controller is provided by a sensor cam and two sensors. The sensor cam is
located on the front of the cable drum and rotates with the motor and cable drum. The sensors are located
in the controller enclosure. As the sensor cam rotates, a cut-out in its face actuates the sensors, signalling
to the valve controller if the valve is closed, open, or somewhere in between. The sensors are a proximity
type and are not affected by any non-metallic contamination of the water.
When the controller receives the open signal from the aircraft, the valve motor rotates clockwise and opens
the valve. When the open sensor is triggered by the cam, the motor turns off and the valve remains in the
open position as long as the open signal is present.
When the operator releases the push button, the open signal is removed. The motor rotates counter-
clockwise and closes the valve. When the closed sensor is triggered by the cam, the motor turns off and
the tube remains in the closed position.
