# Difference between Shunt and Series Regulator

Last Updated on October 26, 2023 by Electricalvolt

## What is a Voltage Regulator?

A voltage regulator is defined as an electronic device used in an electronic circuit to maintain a constant voltage at the output of any electronic circuit within the desired limits, irrespective of the variations in input voltage supplied or load current.

It plays a vital role in transforming unregulated DC power supply to regulated DC supply with no significant variations in the output voltage generated. A voltage regulator is also sometimes referred to as a control element. Based on the arrangement or placement of the control element. The voltage regulator in an electronic circuit can be of the following two types –

• Shunt voltage regulator
• Series voltage regulator

## What is a Shunt Voltage Regulator?

Figure 1 above illustrates that a shunt voltage regulator is always connected in parallel with the load in an electronic circuit. It is observed from Figure 1 that the input voltage applied to the circuit splits into the shunt voltage regulator or the control element and the rest of the current moves to the load. The shunt current (Ish) plays a vital role in maintaining a constant and invariable output voltage at the output.

A sampling circuit and comparator circuit are also present. The sampling circuit present in the electronic circuit generates a feedback signal to the comparator circuit, which in turn compares the applied input reference voltage and the feedback signal to produce a control signal as the difference. This control signal is basically the amount of current to be provided to the shunt voltage regulator element in order to maintain constant voltage output at the load side.

## What is Series Voltage Regulator?

In the case of a series voltage regulator, the control element or the voltage regulator is connected in series with the load at the output as shown in Figure 2 above. The series voltage regulator determines the amount of input voltage reaching the load element at the output end of the circuit.

The series voltage regulator is placed in between the unregulated input voltage supplied and the regulated output voltage, receiving the entire load current. Similar to a shunt voltage regulator, a sampling circuit and a comparator circuit is present.

The comparator circuit compares the feedback signal from the sampling circuit to that of the reference input voltage to generate a control signal. This control signal is then fed to the series voltage regulator element in order to produce a constant and regulated output voltage at the load.

## Difference between Shunt and Series Voltage Regulators

The following table lists the key differences between the shunt and series voltage regulators.

### Conclusion

In conclusion, both shunt and series voltage regulators are electronic circuits that ensure that the generated output voltage is maintained at a steady rate. The most significant difference between them is that the shunt voltage regulator is connected in parallel with the load, while the series voltage regulator is connected in series with the load at the output side of the electronic circuit. However, despite the ability of the voltage regulators to maintain fixed output voltage values across the load, it results in certain instabilities in the normal circuit operation.