Voltage Regulator replacement

mikem wrote:
Jay Masino wrote:


What's the brand name?


It was a Lamar. I didn't write down the model number. It was for a 14V
aircraft, probably a Piper, meaning that the regulator sinks the field
current.

Piper electrical systems source the field current. The other side of
the field winding is connected to ground.

Ray Andraka wrote:
mikem wrote:

Jay Masino wrote:


What's the brand name?



It was a Lamar. I didn't write down the model number. It was for a 14V
aircraft, probably a Piper, meaning that the regulator sinks the field
current.

Piper electrical systems source the field current. The other side of
the field winding is connected to ground.
My Comanche regulator grounds the field wiring. I thought most pipers
were that way.

ktbr wrote:
My Comanche regulator grounds the field wiring. I thought most pipers
were that way.

Well, let me clarify... grounded is for max generator output.
The regulator controls the generator output by controlling
"how much" it is grounded. This could be done in a pulse-width
method or linear method.

ktbr wrote:


It was a Lamar. I didn't write down the model number. It was for a 14V
aircraft, probably a Piper, meaning that the regulator sinks the field
current.

Piper electrical systems source the field current. The other side of
the field winding is connected to ground.

My Comanche regulator grounds the field wiring. I thought most pipers
were that way.

I should have clarified. The Cherokee line uses "B" type regulators.
For those, the regulator is connected between the power buss and the
alternator. Higher voltage at the regulator output (average voltage for
PWM regulators) yields higher alternator output. The other end of the
field winding is grounded. I wasn't aware the the Commanche used the
other type.

Ray Andraka wrote:
mikem wrote:

It was a Lamar. I didn't write down the model number. It was for a 14V
aircraft, probably a Piper, meaning that the regulator sinks the field
current.

Piper electrical systems source the field current. The other side of
the field winding is connected to ground.

I was wrong. I picked up the unit at the airport tonight. It has
"PAC-484121 Voltage Regulator 14V B-00331-2 Lamar, inc. Bancocas N.J.
USA" silk-screened on the cover.
It is a linear regulator. It regulates in the high side (sources
current to the field). If your alternator has two field terminals, you
have to ground the other one..., just like my Cessna. The Lamar unit
came out of a PA32.