How to Make a Simple LED Bulb Circuit

LED lights are become very popular these days.

People also call them LED bulbs or solid state lights.

These lights use very less power like only 0.5 to 3 watts so they save lot of electricity bill.

Before 10 years these bulbs were not so bright.

But still we can make our own easy LED bulb with this guide..

We can show How to Make a Simple LED Bulb Circuit in different colors and also talk about good things of using them.

What is a LED Bulb Circuit:

LED bulb circuit is electric setup that give power to LED bulb and control it.

LED lights uses small chip like semiconductor to make light.

They save more energy than old bulbs like incandescent or tube light.

Inside LED bulb parts change electricity into light and control the current and also do extra things like change color or make light dim.

Circuit Working:

Parts List:

Every year LED become more powerful and more bright because technology improve fast.

White LED is popular for many uses and it give different color of light from warm like old bulb to very white like sunlight from 2700 to 10,000k.

We can choose LED by place and type like diffused LED.

Also it have different beam angle from 10° to 150°.

When technology grows LED price goes down but brightness and efficiency goes up.

Online tool also there to help change brightness into light flowing easily.

Power Supply:

Good power source is needed when using LED bulb with main electricity.

Transformer is not good for small size and low power so people use capacitor based power supply.

Best is class X2 capacitor with 250V AC which helps to reduce high current at start.

Also it uses series resistor between 220Ω to 2.2kΩ.

When power turn OFF one parallel safety resistor around 1M ohm checks capacitor loses charge.

Small bridge diode change AC to DC low voltage.

For normal 5mm LED to online tool can help us find right part values for making LED bulb.

Formulas and Calculations:

Now we show some simple formulas to calculate current for easy LED bulb circuit.

We used capacitor 0.33uF and check how much current come out for 50Hz and 60Hz mains power.

Capacitance (C): 0.33 microFarad (uF) = 0.33 × 10⁻⁶ Farad (F)

Formula:

Xc = 1 / (2 × π × f × C)

where:

• Xc is resistance from capacitor called reactance in ohms Ω
• π (pi) is around 3.14159
• f is frequency Hz

Calculation:

For 50Hz:

Xc_50Hz = 1 / (2 × π × 50 × 0.33 × 10⁻⁶)

Xc_50Hz = 9.55k ohm

For 60Hz:

Xc_60Hz = 1 / (2 × π × 60 × 0.33 × 10⁻⁶)

Xc_60Hz = 7.96k ohm

Now we find the current using this formula:

I = Vin / Xc

where:

• I is current in mA
• Vin is voltage in 120V or 230V

Important:

This is just rough math and it does not count all things in real circuit.

Also never test mains voltage yourself it can be dangerous.

Estimated current:

For 50Hz:

If 120V → I = 120 / 9550 ≈ 12.6 mA

If 230V → I = 230 / 9550 ≈ 24 mA

For 60Hz:

If 120V → I = 120 / 7960 ≈ 15.1 mA

If 230V → I = 230 / 7960 ≈ 29 mA

Note:

These are just guess numbers.

Real current can be lower because of power loss, part quality or safety reasons.

Also this 0.33uF capacitor may not give enough current for many LEDs.

How to Build:

How to Make a Simple LED Bulb Circuit the following steps are needed to be followed:

Choosing an LED:

• Pick LED with color, brightness, current and angle we need.

Power Supply Design:

• Choose power supply type after counting how many LEDs and how much power they need.
• Use X2 capacitor for saving power in capacitor based supply.
• Formula: Q = C × V
• (where, Q = charge C = capacitance V = voltage)

Resistor Calculation:

• To stop high current at start use series resistor between 220Ω to 2.2kΩ.
• Ohms Law: R = V / I where, R = resistance V = voltage I = current

Safety Tips:

• Use one 1MΩ resistor in parallel to make capacitor discharge safe.
• Also put fuse or fusible resistor at input to protect circuit.

Correction:

• Use small bridge diode to fix lower voltage problem.

LED Connection:

• Bridge diode also help with low voltage.
• LEDs usually work with 20mA current.
• Formula to find capacitor: C = I × Δt / ΔV where, C = capacitance I = current Δt = time ΔV = voltage
• Connect LEDs in series up to 20mA without changing parts value.
• If need more current then increase capacitor value.

Making the Circuit:

• Put all parts on PCB (circuit board) with good spacing and insulation.
• Place LEDs into correct socket or base.
• Use electrolyte capacitor to make power more stable and by remove blinking stroboscopic effect and to protect from big starting current.

Safety Precautions:

• Be very careful when working with mains voltage it can be dangerous.
• Cover all metal parts so no one get electric shock.
• Put warning that circuit has no galvanic isolation so risk is higher.
• Make this circuit only at ones own risk.

Note:

Real values can change because different parts give different result and this is just simple guide.

Always check if parts which we use are safe and follow safety rules.

If anyone is not sure about electronics ask someone who knows better.

Electric work is risky so always stay safe at every step.

References:

LED lamp

LED-Lamp Design for Renewable Energy