Briggs & Stratton 86262GS, Familiarization & Troubleshooting Manual

Page: 46 / 128

Section 2 • Generator Components & Systems
Portable Generator Familiarization & Troubleshooting Guide
44
The Brushless Excitation Method
As the engine spins the rotor, residual magnetism induces an
(AC) Voltage into the DPE winding.This voltage is sent to the
excitation capacitor via wires # 2 and # 6.The excitation
capacitor builds up a charge to the point where they
equalize. (The excitation winding and capacitor voltage are
equal.) This builds a magnetic field in the excitation winding
that is intersected by the rotor winding as it is spun by the
engine.
That induces an (AC) voltage in the rotor winding that is
converted to a (DC) voltage by a diode in the rotor winding.
This creates an electromagnet in the rotor assembly. As the
rotor continues to spin, this electromagnetic field intersects
the power winding, inducing an (AC) voltage in the power
winding.
The voltage is regulated by the amount of turns in the
windings and the size of the capacitor and engine RPM.
Figure 2.67 represents the unit schematically. Figure 2.68
illustrates a typical “brushless excitation system.”
Load
Figure 2.67 — Schematic Of Brushless Excitation System
Figure 2.68 — A Brushless Excitation System