The sole function of the regulator is to prevent high voltage by limiting the
generator voltage to a safe preset value.
Charging circuit (pictorial).
Speed vs voltage.
2. RELAY REGULATORS. There are several ways of regulating generator output, but
the most common way is to regulate the field current. Figure 3 shows a typical
generator where the field current is controlled by a variable field rheostat. The
output voltage to the load could also be manually regulated by adjusting the
variable field resistance. The controlling action would be as follows:
a. As the generator speed increases, we would observe an-increase in
voltage on the voltmeter. Since we are manually regulating, we would turn the
variable field resistance down, maintaining the proper voltage output on the
(l) As the generator speed decreases, we would have to increase the
field current to maintain the proper output voltage.
(2) By adjusting the field resistance, we control the field current
(IF), which in turn controls the amount of magnetic flux to the stator, thereby
inducing more or less current (IL) into the stator windings. The rectified current
(IL) goes to the load developing more or less voltage across the load. Now observe
the voltage change and regulate it with the field resistance.
06 010, 5-P2