LCD-LED Display

Mains Operated LED Light Circuit

In this project, I will show you how to build a simple Mains Operated LED Light Circuit, which can light up LEDs directly from the mains supply.


  • Introduction
  • Mains Operated LED Light Circuit Diagram
  • Components used in this Circuit
  • Mains Operated LED Circuit Explanation
    • Rectifier
    • Working of Bridge Rectifier
    • LED
    • Resistor
    • Capacitor
    • Diode
  • Mains Operated LED Light Circuit Working 
  • Advantages of LED Bulbs


Fluorescent bulbs, such as mercury-filled compact bulbs and tube lights, are becoming outdated, with LED lights emerging as their replacement. One significant factor behind this transition is the superior energy efficiency and longer durability of LED lights when compared to fluorescent lamps and tube lights. Towards the conclusion of this article, we’ll delve into the various advantages that LED lights offer over their fluorescent counterparts.

We’ve provided instructions for a straightforward circuit that you can effortlessly create and set up in your home. This circuit not only conserves resources but also saves both energy and money.

Mains Operated LED Light Circuit Diagram

Mains Operated LED Light Circuit

Components used in this Circuit

  • Bridge rectifier – 1
  • Resistor (R1) – 1MΩ
  • Resistor (R2) – 560Ω / 1W
  • Capacitor (C1) – 0.22uF / 400V)
  • LEDs – 5
  • Breadboard
  • Connecting Wires

Mains Operated LED Circuit Explanation

The circuit comprises fundamental elements like a bridge rectifier, resistors, LEDs, and a capacitor, all of which are easily obtainable in the market. Consequently, you can assemble this circuit and install it in your home or office. It’s advisable to review the descriptions of the components before attempting to understand the circuit’s operation.


A rectifier functions as a device for transforming alternating current (AC) into direct current (DC). Rectification is the process that accomplishes this conversion by permitting the flow of electrons in only one direction. In a full-wave rectifier, a circuit is established with the help of four diodes to create a bridge. This technique makes use of both the positive and negative cycles of AC power.

As depicted in the diagram, a bridge rectifier consists of four diodes, namely D1, D2, D3, and D4, giving rise to its designation as a “bridge rectifier.”

Working of Bridge Rectifier

The rectified AC signal is fed into the diagonally opposite terminals of the bridge via the transformer. On the other two terminals of the bridge, we connect the load resistance RL.

During the positive half of the secondary voltage cycle, end P takes on a positive charge while end Q becomes negative. Consequently, diodes D1 and D3 are forward-biased and initiate conduction, while diodes D2 and D4 become reverse-biased and cease conduction.

Given that diodes D1 and D3 are in series with the load resistance RL, current is directed through it, as shown in the diagram.

During the negative half of the secondary voltage cycle, we observe a reversal in polarity with end P becoming negative and end Q becoming positive. This condition causes diodes D2 and D4 to become forward-biased and commence conduction, while diodes D1 and D3 switch to a reverse-biased state. Notably, diode D2 is forward-biased in this configuration.

Since diodes D2 and D4 are linked in series with the load resistor RL, current flows through RL as depicted in the diagram. It’s evident that the current follows the same path from point A to point B through the load as it did during the positive half cycle. Consequently, a direct current (DC) voltage is established across the load RL. Figure 1 provides a visual representation of the output waveform produced by a bridge rectifier. It’s worth noting that the output voltage of a bridge rectifier surpasses that of both full-wave and half-wave rectifiers.


Light emitting diode are different  from other diodes as they emit light and hence referred as light emitting diode. LED are available in RED, GREEN, BLUE color.


In various ways, all materials exhibit resistance to the primary flow. Resistance is the term used to describe this form of opposition, and it depends on the abundance of free electrons within a material. To ascertain the resistance in an electronic or electrical circuit, a range of resistor types can be employed, including but not limited to carbon film, carbon composition, filament resistor, and numerous others.

With the following equation, the resistance of a circuit is determined by p, L, and A.

R = L/Apppppppppp*p


Capacitance denotes the quantity of electrical energy stored at a particular voltage level within a capacitor, which is a specialized apparatus designed for the storage of electrical energy. A capacitor is intentionally crafted to possess a designated capacitance value, allowing it to accumulate electrons for subsequent discharge. This component consists of two metal plates separated by a non-conductive material referred to as the dielectric.


A diode serves as an electrical component that permits the flow of electric current in only one direction. Forward-biased diodes are produced by uniting N-type and P-type semiconductors. The N-type semiconductor contains mobile free electrons, while the P-type semiconductor features electron-absent regions called “holes.” In close proximity to the junction between these two materials, electrons from the N-type semiconductor traverse the junction and occupy the holes in the P-type material. In a similar fashion, holes near the junction of the P-type material cross over to fill the vacancies left by electrons. This interaction at the junction of the PN semiconductor gives rise to the formation of a depletion layer.

Mains Operated LED Light Circuit Working 

The operation of this circuit is quite straightforward. Follow the circuit diagram for assembly, and then connect it to the AC mains. In this setup, resistor R2 acts as a current limiter, while resistor R1 functions as a discharge resistor for capacitor C1, safeguarding against any potentially dangerous electrical shocks.

The electrical power from this point is directed into the bridge rectifier circuit, which converts AC to DC while also regulating the voltage using current-limiting components. This converted power is then directed to the LEDs, causing the LED connected to the output to illuminate. You have the option to either purchase a bridge rectifier or construct your own using four diodes. You can use a total of up to 20 LEDs in this setup.

Advantages of LED Bulbs

  • In comparison to fluorescent and incandescent lights, LED bulbs last ten times longer.
  • Because LED bulbs do not include a filament, they are less likely to be damaged.
  • The common incandescent bulb becomes hot and generates a lot of heat in the room, but the LED light prevents heat buildup and helps to save money on air conditioning.
  • In comparison to fluorescent lamps, LED lamps consume about 2-17 watts, or about 1/3 of the power. So, if you use an LED light, you can save a lot of money on your electric bill.
  • Because LED lamps use extremely little energy, they are increasingly being used in solar panels.
  • Many individuals have inverters in their homes, and they are increasingly using LED lights with inverters to extend the amount of time that inverters can sustain LED light.
  • Although the initial cost of an LED bulb is higher than that of a fluorescent bulb, they have a longer lifespan, can be readily moved from one location to another without breaking, and save electricity. As a result, LED bulbs are more energy efficient than fluorescent bulbs.
  • Temperature and humidity have no effect on LED lights.
  • LED bulb does not contain mercury also hence do not provide harm to environment also.
  • LED lights will turn on instantly.

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