How Light bulbs Work | How To make LED light Bulbs | Types of LED bulbs |E27 led bulb:

 The first question that comes to mind about the LED light bulbs is how it works? 
Now, first we start with the assembly of the LED or Light Emitting Diode Bulb and how its been made in home. The various components of LED diode has many parts such as:
1. The Translucent/milky/Transparent upper cap from which we get the light.
2. The Plastic/Aluminium Body of the Bulb. 
3. The bottom cap of the bulb which is usually put in bulb holder.
These three parts combined to be called as Housing of the LED bulb.
4. The Circuit/PCB of the bulb which contains the LED’s in it which illuminate to give light and the LED driver in it which drives the circuit or in precise language changes the 220v AC current to a 12 v to drive the LED’s
5. Small wires that drive the current from the bottom cap to the LED circuit.

How LED Bulbs Work?
When we attach the LED bulb to a Holder in which we have the 220/230v AC current supply, the current gets passed from the wires of the bulb to the driver in the PCB. The driver converts the 220/230v to 12v for the LED’s.
The LED’s then emits light. This is measured in lumens of the led’s. The more the Lumens of the led the more the brightness of the bulb.
What LED is used in Bulb?
Generally, there are many types and models of led but SMD2835 is much more used. 
What size of LED bulbs Available? 
There are many sizes available according to the wattages like 3W, 5W, 7W, 12W, 18W, etc.

What numbers of  Led’s are used in a bulb?
Number of LED is used according to the Wattage of the led bulb that has to be made. Below is the chart:
Watts SIZE(mm) No. of LED’s POWER Lumens SOCKET
3W 82*55mm 10pcs SMD2835 3W 200LM B22/E27
5W 100*60mm 18pcs SMD2835 5W 360LM B22/E27
7W  110*68mm 21pcs SMD2835 7W 420LM B22/E27
9W 120*78mm 30pcs SMD2835 9W 600LM B22/E27
12W 142*95mm 45pcs SMD2835 12W 900LM B22/E27
15W 92*160mm 30pcs SMD5730 15W 1500LM B22/E27
18W 95*160mm 36pcs SMD5730 18W 1800LM B22/E27
Now, What is a Socket and how led bulbs work for it?
The socket is the type of male/female combination of bulb bottom and the holder. A B22 is the spiral male-female while a E27 is the simple in-out male-female type shown below:
What types of Housing/plastic body are available for led bulb? There are many types shown below:

How to Assemble/make a LED bulb? Steps to follow:
1. Firstly, gather the items Led housing/body (3). Upper cap, middle body & bottom cap(E27 /B22 type), Circuit usually comes with driver, 2 small wires ( 110 mm or more in length according to the size of the bulb).
For example, 5W led bulb:
Gather 5w led bulb housing/body (100*60mm), 18pcs led bulb circuit with driver, 2 small wires of length 105mm approx.
2. Now, solder one ends of 2 wires in negative and positive of the circuit respectively.
3. Put this in the middle body and take out the other two ends of wires from the bottom of the middle body.
4. Solder the other two ends of wires in the bottom cap.
5. Attach the bottom cap to the middle body and lock it through cap locking hand tool as shown.
6. Attach the PCB in the middle body and put the upper cap to the middle body.
7. A small glue can be put in between the upper cap and middle body to make it sealed.
8. Last test to attach the bulb to the battern holder and check it.
9. Pack the bulb in respective cartons and could be sold in markets.
The Question arouse to your mind as why led bulbs are better than cfl?

If for example, there are 100 no.s of cfl of 5W in house and replace by 100 no.s led 3W (as lumens are same). Then the power saved is (5*100)-(3*100)= 200 w per hour. That means in a day in 10 hr consumption pattern 10*200W= 2kW
In a month, 2kW*30 days= 60 kWh
Amount saved per bill if assumed $0.1/kWh=60*0.1=$6 saved per month and 60 kWh saved per household in a country. Moreover it is experimented that the life of a LED bulb is more then CFL. This is how Lights bulb work.
Thus energy saved is energy produced. Save Electricity!