# Full Wave bridge rectifier circuit with working explanation

What is a rectifier? A rectifier is an electronic circuit that converts AC voltage to DC voltage. It can be implemented using a capacitor diode combination. The unique property of diodes, permitting the current to flow in a single direction is utilized in here.Now what is a bridge rectifier? Bridge rectifier is a full wave rectifier circuit using the combination of four diodes to form a bridge. It has the advantage that it converts both the half cycles of AC input into DC output.

Rectifiers are one of the basic electronic circuits. If you are an electronic hobbyist then this tutorial will help you to get started with your lessons in electronic circuits.

A good bridge rectifier power supply (rectifier applications) is essential to start your home electronics lab. Below is the full wave bridge rectifier schematic and operation explanation in detail.

## Components Required

1. Step down transformer-1 (230V to 12V or 110V to 12V)
2. Diodes-4 (1N4007)
3. Capacitor-1 (470µF)
4. Led-1 (Red)
5. Resistor-1 (1K)
NOTE: You can use step down center tapped transformer as well as ordinary step down transformer. If you choose a center tapped transformer it is possible to change the output DC. By connecting middle point and a terminal point of transformer to rectifier or by connecting both terminal points of transformer to the rectifier voltage can be changed.

## Working of a bridge rectifier

• During the positive half cycle of secondary voltage, diodes D2 and D3 are forward biased and diodes D1 and D4 are reverse biased. Now the current flows through D2–>Load–>D3
• During the negative half cycle of the secondary voltage, diodes D1 and D4 are forward biased and rectifier diodes D2 and D3 are reverse biased. Now the current flows through D4–>Load–>D1
• In both the cycles, load current flows in the same direction. Hence we get a pulsating DC voltage as shown in fig (2).
Fig (1). Input sine wave
Fig (2). Pulsating DC output
• Addition of a capacitor at the output converts the pulsating DC voltage to fixed DC voltage.
• Upto a time period of t=1s input voltage is increasing, so the capacitor charges up to peak value of the input. After t=1s input starts to decrease, then the voltage across the capacitor reverse biases the diodes D2 and D4 and therefore it will not conduct. Now capacitor discharges through the load, then voltage across the capacitor decreases.
• When the peak voltage exceeds the capacitor voltage, diodes D2 or D4 forward biases and as a result capacitor again charges to the peak value. This process continues. Hence we get almost smooth DC voltage as shown in fig (3).
Fig (3). Filtered output

## 10 thoughts on “Full Wave bridge rectifier circuit with working explanation”

1. TITO says:

when converting Ac to Dc their values remain the same or they also change?

2. Satyaprakash Singh says:

3. versha says:

I don’t have a capacitor in my circuit on its place I have a bulb how can I explain the circuit

• Let’s say we have a normal circuit with a light bulb, with wires and a battery.

When one places a capacitor in this circuit, how is the light bulb able to light up, even when the capacitor prevents the flow of charge? Also, why does it dim and then go out eventually?

Then when the battery is removed from this circuit, how is the light bulb still able to light up? And what is happening when the light bulb dims and goes out in this situation as well?

First, note that the light bulb is essentially just a glorified resistor. As current flows through the filament, Joule heating causes the filament to get hot and emit light.

When one places a capacitor in a circuit containing a light bulb and a battery, the capacitor will initially charge up, and as this charging up is happening, there will be a nonzero current in the circuit, so the light bulb will light up. However, the capacitor will eventually be fully charged at which point the potential between its plates will match the voltage of the battery, and the current in the circuit will drop to zero. This is when the light bulb will dim and then fizzle out.

When the battery is removed from the circuit, there is nothing to maintain the potential difference between the plates, and the capacitor will discharge. As this happens, there will once again be a nonzero current flowing through the circuit, and the bulb will light up. However, the current will steadily decrease as the capacitor discharges and will eventually drop to zero at which point the bulb will go off.

4. Daniel Renton says:

Can you please explain the operation in detail of a bridge rectifier when single phase AC is the input signal

5. santosh says:

for higher rating like 12V 20A is it sutable

6. Dr. Shanu says:

Hello Sir,
I am having a centre tapped 12 – 0- 12 transformer. Can I connect both the terminals, and leave the wire at the centre as shown in the circuit given above?

7. ravi kumar says:

why deside the value of capacitor,,,,,,,,,,,,,,,,,,,tell me sir

8. Swati says:

Can I get to know a working of capacitor input filter for brigde rectifier