Alternator

[dave4754]

I have an alternator from an R22 helicopter and cant tell if it has an internal regulator?

It started life as a Prestolite alternator, would anyone here know how i could tell if it has an internal regulator?

no plate on it.

[Jermechanic]

Take it by an alternator repair shop. They would be able to test it and tell you.

[lr172]

An externally regulated alt will have a B lead (power) a Neg lead and a Field lead. Most modern internally regulated Alt's only have a power lead and possibly a ground lead. However, some older internally regulated Alt's also had a field lead.

If it has no filed lead, it is internal. If it has one it probably is external, but maybe not. I unfortunately have no experience with the prestolite Alt's, only general automotive.

Larry

[dave4754]

thanks for the help. It appears to be an internally regulated Prestolite with two field attach, field 1 and field 2. I am given to understand that one is grounded and the other of course goes to the Alt. switch on the panel.

Any other opinions on this greatly accepted.