Automatic Air Flow Control

A/C auto amp. decides target air flow depending on target air mix door opening angle.
A/C auto amp. changes voltage to power transistor gate and controls air flow in 31 stages, so that target airflow is achieved.
When air outlet is VENT or B/L, the minimum air flow is changed depending on sunload.

Fig 1: Automatic Air Flow Control Function Graph
Courtesy of NISSAN NORTH AMERICA, INC.