Subaru SVX 1992 Manual page 958

4-7 [M4019] AUTOMATIC AIR CONDITIONING SYSTEM
19. MODE DOOR MOTOR
The mode door motor is installed on the left side of the
heater unit, and is controlled by the signal sent from the
auto amplifier. This motor actuates the defroster door,
vent door and heat door via linkage mechanisms so as
to nrovide ontirnum air rirrulation_
1) Operation of mode door motor
The auto amplifier determines the mode door position .
The mode door motor rotates normally or in reverse
direction corresponding to the auto amplifier signal as
shown below .
The output shaft and sliding contact are made integral .
If the sliding contact exceeds the position of terminal
plate ® or ® (DEF or VENT position), the current is cut
off and the motor stops rotating .
If the auto amplifier output signal turns OFF, the motor
operation stops irrespective of the position of the slid-
ing contact .
Energizing terminal
Direction of
Positive 0+
Negative
rotation
Remarks
1Q Q CCw VENT -> DEF
Q 1Q
Cw
DEF - VENT
~A
P.B .R .
Terminal
Auto
plate
amp.
I VENT *
2 1
Terminal plate ©
7 6 5 4
C4-422
Fig . 61
2) P .B .R. (Potentiometric Balance Resister)
The potentiometric balance resister is built into the
printed board in the mode door motor. This resister
detects the mode door position corresponding to the
output shaft rotation as a ratio of variable terminal
voltage VM to reference voltage Vpo, and feeds the
signal back to the auto amplifier.
VENT DEF
0 .s
Radio
VM
5 3 4
VDD
VM
0.1
VDD 0
VENT
DEF
Mode door position
C4-423
Fig. 62
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