Simple 220V LED Night Lamp Circuit

This circuit design lets a night light operate directly from your homes standard electrical outlet typically 220V AC.

It achieves this by either using a transformer or special capacitors to bring the voltage down to a safe level for the LED lamp.

Circuit Working:

Parts List:

White Light Emitting Diodes LEDs now offer a compelling alternative to incandescent lamps in lighting applications.

Modern White LEDs are cost effective consume less power and produce a focused beam.

Presented here is a basic circuit for an efficient white LED Night Light that can be directly powered from an AC 220V supply.

It utilizes a “capacitive transformerless power supply,” where a capacitor and resistor in series with an AC source can maintain a constant current through the resistor provided the capacitors reactance is much higher than the resistance.

With a 0.47µF capacitor, the current reaches approximately 70mA at 220V AC 50Hz input.

To convert this AC voltage to DC rectifiers and filter capacitors are added.

In this design, a 12VDC 70mA capacitive transformerless power supply is used to power three 5mm white straw-hat LEDs.

An advantage of this circuit is that the output voltage remains safe even if the LED string is disconnected.

This safety feature is achieved with two zener diodes (ZD1 and ZD2) as part of the bridge rectifier unit.

In traditional capacitive transformerless power supply LED circuits, there is a risk of filter capacitor explosion in an open load condition.

Resistor R1 limits inrush current chosen to balance power dissipation and inrush current.

Capacitor C1 is crucial controlling the maximum current flow through the components.

Electrolytic capacitor C2 stores current for the load and should be rated at twice the expected output voltage.

Resistor R3 limits the operating current of the three white LEDs LED 1 to 3 in series.

This circuit is suitable for various lighting applications including staircases, corridors, wardrobes, bedrooms and bathrooms.

Formulas:

A capacitor is used in transformless capacitive power supplies to reduce the mains voltage to a level that is tolerable.

The output voltage, current, and ripple are strongly influenced by the value of the input capacitor.

Formula for Input Capacitor Value

The following is the main formula to get the value of the input capacitor C1:

C1 = I_out / (2 * f * V_ripple)

where,

• The farads value of the input capacitor is C1.
• F is the primary frequency either 50 Hz or 60 Hz, and Iout is the required output current in amps.
• The intended peak to peak ripple voltage across the capacitor is called ripple.

Note:

Using the given circuit arrangement and the above formulas , you may successfully build 220V LED Night Lamp Circuit by comprehending these fundamental ideas and choosing components with care.

How to Build:

To build a Simple 220V LED Night Lamp Circuit follow the below mentioned steps:

Safety First:

• Ensure the circuit is not connected to power while assembling.

Connect Capacitor C1 and Resistor R1 in Series:

• Connect the 0.47 capacitor C1 and a suitable resistor R1 in series to the AC 230V supply.
• The value of R1 should limit inrush current but not dissipate too much power.
• The specific values will depend on the desired current and voltage.

Connect Capacitor C2:

• Connect the electrolytic capacitor C2 in parallel with the output.
• C2 should be rated at least twice the expected output voltage.

Connect Resistor R3 and LEDs:

• Connect resistor R3 in series with the three white LEDs LED1 to 3.
• R3 should limit the operating current of the LEDs.
• The values of R3 and the LEDs depend on the desired current for the LEDs.

Test and Adjust:

• Once the circuit is assembled, test it with a power source.
• Adjust the values of R1, R3 and the LEDs if necessary to achieve the desired brightness and current.

Enclose the Circuit:

• Once the circuit is working correctly enclose it in a suitable housing to protect against accidental contact and to diffuse the light from the LEDs.

Install the Night Light:

• Install the night light in the desired location, such as staircases, corridors, wardrobes, bedrooms or bathrooms.

Note:

• Please note that working with high voltage can be dangerous, and it is essential to take proper safety precautions.
• If you are not experienced with working with electronics, consider seeking assistance from someone with more experience.

Conclusion:

A 220V LED night lamp circuit is a simple and efficient way to power a night lamp using the standard 220V AC power supply.

By using components like capacitors, resistors, zener diodes and a bridge rectifier, it is possible to create a safe and reliable circuit for illuminating a night light in various settings.

References:

Nightlight