Blowing voltage regulators
Using this drawing from a 1966 booklet.
When the system voltage is low (relative to the set point), not much current flows through the coil.
The spring holds the upper contacts together.
Current flows directly through the regulator to the alternator's rotor.
The only resistance in the circuit is the rotor windings. This limits the current flow to 2 or 3 amps. (specs vary with specific alternator).
If there is a short to ground, then there is no resistance and current flow will increase greatly.
Then the fusible link melts and there's no flow.
Those illustrations are from this booklet.
Link is to page 5 which addresses the fusible wires but the whole beginning should be useful.
Alternators and Regulators (Session 228) from the Master Technician's Service Conference
Using this drawing from a 1966 booklet.
When the system voltage is low (relative to the set point), not much current flows through the coil.
The spring holds the upper contacts together.
Current flows directly through the regulator to the alternator's rotor.
The only resistance in the circuit is the rotor windings. This limits the current flow to 2 or 3 amps. (specs vary with specific alternator).
If there is a short to ground, then there is no resistance and current flow will increase greatly.
Then the fusible link melts and there's no flow.
Those illustrations are from this booklet.
Link is to page 5 which addresses the fusible wires but the whole beginning should be useful.
Alternators and Regulators (Session 228) from the Master Technician's Service Conference
