System Description

AUTOMATIC AIR CONDITIONER SYSTEM


WITHOUT LEFT AND RIGHT VENTILATION TEMPERATURE SEPARATELY CONTROL SYSTEM : System Description


CONTROL OPERATION

Display Screen
The operation status of the system is displayed on the screen.






Preset Switch






MODE Switch
The air discharge outlets is controlled with these switches.

Temperature Control Dial (Potentio Temperature Control)
The set temperature is increased or decreased with this dial.

AUTO Switch
- The compressor, intake doors, air mix doors, mode doors and blower speed are automatically controlled so that the in-vehicle temperature will reach, and be maintained at the set temperature selected by the operator.
- When pressing AUTO switch, air inlet, air outlet, fan speed, and discharge air temperature are automatically controlled.

Defroster (DEF) Switch
Mode doors are set to the defrost position with this switch. Also, intake doors are set to the outside air position, and compressor turns ON.

A/C Switch
Compressor is ON or OFF with this switch.
(Pressing the A/C switch when the A/C switch is ON turns OFF the A/C switch and compressor.)

Fan Control Dial
The blower speed is manually controlled with this dial. Seven speeds are available for manual control (as shown on the display screen).

OFF Switch
Compressor and blower are OFF, air inlet is set to FRE, and mode position is set to foot position.

Rear Window Defogger Switch
When indicator is ON, rear window is defogged.

Intake Switch
- When intake switch is ON, FRE indicator turns ON, and air inlet is fixed to FRE.
- When intake switch is pressed again, REC indicator turns ON, and air inlet is fixed to REC.
- When intake switch is pressed for approximately 1.5 seconds or longer, FRE and REC indicators blink twice.
Then, automatic control mode is entered. Inlet status is displayed by indicator even during automatic controlled.
- When FRE indicator is turned ON, shifting mode position to D/F or DEF, or when compressor is turned from
ON to OFF, intake switch is automatically turned OFF (fixed to FRE mode). REC mode can be re-entered by pressing intake switch again, and then compressor is turned ON. (Except D/F or DEF position)

DISCHARGE AIR FLOW






SWITCHES AND THEIR CONTROL FUNCTION











AIR CONDITIONER LAN CONTROL SYSTEM
The LAN (Local Area Network) system consists of unified meter and A/C amp., mode door motor, air mix door motor and intake door motor.
A configuration of these components is as shown in the figure below.






SYSTEM CONSTRUCTION
A small network is constructed between the unified meter and A/C amp., mode door motor, air mix door motor and intake door motor. The unified meter and A/C amp. and motors are connected by data transmission lines and motor power supply lines. The LAN network is built through the ground circuits of each door motor.
Addresses, motor opening angle signals, motor stop signals and error checking messages are all transmitted through the data transmission lines connecting the unified meter and A/C amp. and each door motor.
The following functions are contained in LCUs built into the mode door motor, the air mix door motor and the intake door motor.
- Address
- Motor opening angle signals
- Data transmission
- Motor stop and drive decision
- Opening angle sensor (PBR function)
- Comparison
- Decision (Unified meter and A/C amp. indicated value and motor opening angle comparison)






Operation
The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp. sends mode door, air mix door and intake door opening angle data to the mode door motor LCU, air mix door motor LCU and intake door motor LCU.
The mode door motor, air mix door motor and intake door motor read their respective signals according to the address signal. Opening angle indication signals received from the unified meter and A/C amp. and each of the motor position sensors is compared by the LCUs in each door motor with the existing decision and open- ing angles. Subsequently, HOT/COLD, DEF/VENT and FRE/REC operation is selected. The new selection data is returned to the unified meter and A/C amp.






Transmission Data and Transmission Order
Unified meter and A/C amp. data is transmitted consecutively to each of the doors motor following the form as shown in the figure below.

START:
- Initial compulsory signal is sent to each of the door motors.

ADDRESS:
- Data sent from the unified meter and A/C amp. are selected according to data-based decisions made by the mode door motor, air mix door motors and intake door motor.
- If the addresses are identical, the opening angle data and error check signals are received by the door motor
LCUs. The LCUs then make the appropriate error decision. If the opening angle data have no error, door control begins.
- If an error exists, the received data are rejected and corrected data received. Finally, door control is based upon the corrected opening angle data.

OPENING ANGLE:
- Data that shows the indicated door opening angle of each door motor.

ERROR CHECK:
- In this procedure, transmitted and received data is checked for errors. Error data are then compiled. The error check prevents corrupted data from being used by the mode door motor, the air mix door motor and the intake door motor. Error data can be related to the following symptoms.
- Malfunction of electrical frequency
- Poor electrical connections
- Signal leakage from transmission lines
- Signal level fluctuation

STOP SIGNAL:
- At the end of each transmission, a stop operation, in-operation, or internal malfunction message is delivered to the unified meter and A/C amp. This completes one data transmission and control cycle.