Posted by Vaughn on Saturday, November 12, 2005 at 10:00AM :
In Reply to: electrical question on regulators... posted by George in NW Michigan on Friday, November 11, 2005 at 9:54PM :
The cutout prevents current from being drawn back into the generator windings to prevent possible damage.
Once the engine is running, the generator action increases with engine rpms until it begins to put out current. This causes the regulator relay to energize and close the cutout contacts, so that current will flow through the ammeter to the battery.
The reversal of current flow through the ammeter causes the needle to swing from the discharge zone (battery doing the work) to the charge zone (charging system doing the work).
When the engine is slowed down, the charging system output weakens and the ammeter needle gradually returns to "zero" - the point where the charging system is just meeting the needs of the electrical system load and no more.
If the engine is allowed to idle - especially with several electrical accessories in operation, the ammeter needle will swing down into the discharge zone indicating that the current flow has reversed and the battery has assumed some, or all, of the electrical systems load.
Should the charging system output fall very low, current would be drawn back into the generator windings resulting in a loss of current and possible damage to the generator windings. The cutout prevents this.
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