The voltage control unit BRN120T5A-3C is designed to stabilize the voltage of the GN30NZh412 generator within 115...119 V when its load and rotation frequency change.

Compound:

- MO - measuring organ;

- PS - phase shifter;

- PS1, PS2, PS3 - pulse shapers;

- ED - executive device;

- К - generator excitation relay.

The power source for the generator excitation and the unit operation is the generator booster. 
 
The unit body is made in the form of a cassette and is installed on the RMB-1B mounting frame in compartment No. 7 of the right wing overflow. 

There is a trimmer resistor on the front panel of the unit.

Principle of operation:

To eliminate auto-oscillations of the voltage during the regulation process, a flexible negative feedback on the exciter excitation current is provided, implemented using a stabilizing transformer TC and a resistor R4. 
 
The voltage applied to R4 is summed with the signal of the measuring body and proportionally the rate of change of the excitation current of the exciter.

In steady-state modes of generator operation, the average value of this voltage is zero. 
 
In transient modes of operation, the feedback signal always prevents changes in the conductivity of the transistor VT1 FSU and, thus, provides damping of voltage regulation processes.