Originally Posted By: StevieC
My Dodge Journey has a clutch on the pulley but the voltage regulator keeps the voltage the same regardless of acceleration, deceleration and idling. That's really weird if that is what it is. Haven't seen that before. (Smart Alternator Charging)
The clutch you speak of might be an over-running clutch. Think of a bicycle that you get up to speed then stop pedaling. The clutch on the wheel lets it keep spinning without forcing the pedals to move as well.
In this case, it will let the alternator spin faster than the belt drive for example right after a gear shift.
Alternatively, it might be a decouple when the engine speed gets really high.
These smart charging solutions don't actually decouple the alternator from the engine, they are telling the voltage regulator what they want, and then the regulator does its thing.
In this case, they are telling the regulator, "I want 12.6V" and the regulator maintains 12.6V. When you turn on the headlights, they ask for 14.4V, and the regulator does that instead.