alternator c172
many thanks for your replies.
Hopefully this time i get it right.
The alternator represents the primary source of DC power when the engine is running and it basically consists of a stationary armature and of a rotating field coil driven by the engine through a drive belt and trickle charged from the battery through the ACU and an alternator contactor field, generating an electromagnetic field: as the coil revolves around the stationary armature, it induces as a result of an electromagnetic induction phenomenon a certain amount of induced current into the armature then converted into a direct current flow by rectifier, and the magnitude of which depends upon the strength of the electromagnetic field and thus of the trickle charge and upon the rotational velocity of the field coil with respect to the armature.
The alternator is used in conjunction with an ACU or Alternator Control Unit housed in a power junction box also referred to as the Master Control Unit or MCU located on the forward left side of the firewall and designed to provide a constant 28.5VDC supply to the Main Bus system, by increasing the trickle charge and thus the strength of the electromagnetic field as the load on the electrical system is increased or as the engine spools down or by decreasing it as the load on the electrical system is decreased or as the engine spools up.
In addition the ACU will provide a low voltage indication should the main bus voltage supply drop below 24.5VDC; over-voltage protection should the voltage supply to the main bus exceed 31.5VDC forcing an ALT FIELD CB open, cutting off the trickle charge to the field coil, causing the electromagnetic field to collapse and thus the output of the alternator to drop as reflected by a drop on the voltmeter and by a discharge indication on the ammeter as the battery copes with the extra load and reverse current protection.
Alternator operation is controlled by the ALT half of the split rocker switch that when turned ON it will energize the ACU and the alternator contactor field, restoring the trickle charge to the field coil and thus flashing the electromagnetic field back.
anything to review, or add to it?
Thanks
Baobab72