What is the role of the voltage regulator tube in the DC power supply?
The DC power supply voltage remains constant regardless of the load, as is well known when discussing the idea of a voltage regulator tube. That is to say, the power supply voltage stays at the design value regardless of how the load current varies. So you need to be aware of the following.
Zigzag diode
The Zener diode, also known as the ZENER diode, operates in the reverse breakdown state, as seen in the above image. Reverse bias voltage (VR) increases cause the reverse current (IR) to increase gradually; however, the reverse current increases abruptly when the reverse bias voltage reaches a particular value, or the breakdown voltage. The reverse current is steady right now. Nearly the breakdown voltage VZ is the voltage at the voltage regulator's two portions. At this point, the voltage hardly varies at all, regardless of how much the current fluctuates. This is the voltage regulator tube's principle of voltage stability.
Assume that the alternating current grows and the voltage U1 across the filter capacitor C increases when the load voltage U0 is stable at the breakdown voltage VZ of the voltage regulator tube. The voltage regulator tube's volt-ampere characteristics rise as the load voltage U0 does as well. As can be seen, there is a noticeable increase in the current flowing through the voltage regulator tube at this point. This leads to a rise in the voltage drop across the current limiting resistor R, which lowers the load voltage and approaches the voltage regulator tube's breakdown voltage VZ in order to reach equilibrium.Analyzing the scenario when the alternating current drops is also possible. Both the load voltage U0 and the current passing through the voltage regulator tube are now substantially lower. As a result, the load voltage rises as the voltage drop across the current limiting resistor R drops. After getting close to the voltage regulator tube's breakdown voltage (VZ), it approaches equilibrium.
