A vehicle electrical system comprises a generator, voltage regulator, switch module, and control device. The generator includes a field coil and one or more stator windings coupled together via the switch module. The generator provides electrical current to one or more electrical loads. The voltage regulator maintains the generator output voltage at a constant voltage by varying the field current. The switch module may include low-power transistors. The control device monitors the field current, output voltage and stator current and applies control signals to the switch module to improve transient recovery due to sudden variations in the electrical load and increase system efficiency during normal operation.