Simple and adjustable voltage regulator for motorcycles with 3-phase alternating current generators and separate rectifiers like most 2-valve BMW or Moto Guzzi. The charge threshold could be adjusted to your need, which will increase the efficiency of charging your battery.
Here you can simulate the circuit, press „Start Simulation“ and turn the voltage knob at the power supply to see how the regulation works. To adjust the charge threshold turn the knob of the potentiometer.