Single Phase Full Wave Controlled Rectifier | New Topic 2025

In this note, we are going to know about Single Phase Full Wave Controlled Rectifier and also about its types, circuit diagram, working principle, applications as well. Welcome to Poly Notes Hub, a leading destination for engineering notes for diploma and degree engineering students.

Author Name: Arun Paul.

What is Single Phase Full Wave Controlled Rectifier?

A single phase full wave Controlled Rectifier is a type of rectifier circuit that uses two pairs of diodes or thyristors to convert alternating current (AC) voltage to direct current (DC). It is commonly used in DC motor drives, battery charging systems, and other applications that require regulated DC output.

Types of Single Phase Full Wave Controlled Rectifier

There are two types of Single Phase Full Wave Controlled Rectifier –

• Single Phase Full Wave Controlled Rectifier with R Load
• Single Phase Full Wave Controlled Rectifier with RL Load

About Single Phase Full Wave Controlled Rectifier with R Load

A single phase full wave Controlled Rectifier with R load (resistive load) is a type of rectifier circuit that uses two pairs of diodes or thyristors to convert alternating current (AC) voltage to direct current (DC). It is commonly used in DC motor drives, battery charging systems, and other applications that require regulated DC output.

Circuit Diagram of Single Phase Full Wave Controlled Rectifier with R Load

Working Principle of Single Phase Full Wave Controlled Rectifier with R Load

The operation of the Single Phase Full Wave Controlled Rectifier with R Load is based on triggering the thyristors in pairs during each half-cycle of the AC supply. The waveform is divided into two modes: positive half-cycle and negative half-cycle.

1. For Positive Half Cycle
   • When the AC voltage is positive, thyristors T1 and T2 are triggered.
   • These thyristors conduct, and the load current flows through T1, the load resistor, and T2.
   • The output voltage is equal to the input AC voltage.
2. For Negative Half Cycle
   • When the AC voltage is negative, thyristors T3 and T4 are triggered.
   • The current flows through T3, the load resistor, and T4 in the opposite direction.
   • Again, the output voltage is positive because the load is resistive.

Applications of Single Phase Full Wave Controlled Rectifier with R Load

Here are the applications of 1 Phase Full Wave Rectifier with R Load –

1. Used in Battery Charging System.
2. Used in Motor Drives.
3. Used in Heating Control System, Electroplating Purposes, and in Welding Equipment as well.

About Single Phase Full Wave Controlled Rectifier with RL Load

A Single Phase Full Wave Controlled Rectifier with an RL Load is an AC to DC converter that converts a single-phase AC input voltage to a controlled DC output voltage via thyristors (SCRs). This sort of converter is widely used in applications that require controlled DC power, such as motor drives, battery charging, and power supplies.

Circuit Diagram of Single Phase Full Wave Controlled Rectifier with RL Load

Working Principle of Single Phase Full Wave Controlled Rectifier with RL Load

In a single phase full wave controlled rectifier with RL load, the operation can be explained separately for the positive and negative half cycles of the AC input voltage.

During the positive half cycle, the AC input voltage is positive, and thyristors T1 and T2 are forward-biased. At the firing angle α, gate pulses are provided to T1 and T2, turning them on. Current then flows through T1, the load, and T2, delivering power to the load. The output voltage across the load follows the input voltage from the firing angle α until the end of the positive half cycle at π. The inductive nature of the load causes the current to lag behind the voltage, which ensures that the current continues to flow even beyond π, until it naturally commutates.

In the negative half cycle, the AC input voltage reverses polarity, making thyristors T3 and T4 forward biased. At a firing angle π+α, gate pulses are applied to T3 and T4, turning them on. Current flows through T3, the load, and T4, again delivering power to the load. The output voltage follows the negative half of the input voltage from π+α to 2π. As in the positive half cycle, the inductive load ensures that the current lags, allowing for continuous conduction even after the input voltage crosses zero.

By controlling the firing angle α, the average DC output voltage can be regulated, making the converter suitable for applications like DC motor drives and controlled DC power supplies.

Applications of Single Phase Full Wave Controlled Rectifier with RL Load

Here are some applications of 1 Phase Full Wave Controlled Rectifier with RL Load –

1. DC motor drives.
2. Battery charging.
3. Power supplies with controlled DC output.