Introduction: LED Bulb
Hello Everyone, I want to share this interesting project which is 240 Volt Mains operated and costs about INR 60 or is less than $1.
The Led's are 5050 smd type means it is 50mm x 50mm in dimensions and mainly used for surface mounting on pcb, you can use through hole led also. This Led bulb contains seven smd led's of 0.2 watt each.So total power consumption uses is approx.1.6 watt including power wattage of all components.Let's Begin..:)
WARNING: Working with 240 volt is very dangerous if any loose connection or misplaced component is present.Be very careful..
Step 1: Components & Description
a) 5050 Smd Led - Seven in Numbers which costs INR 2.50 each.Actually there are three white led's in one package.So there are three pins at both side of cathode and anode,don't confuse with them.Simply solder these three with each other.The polarity mark on Smd shows the cathode terminal.
b) Metallized Polyester Capacitor - The most important component for lowering down the current and voltage.This capacitor doesn't have any polarity. Xc=1/2pifc is the capacitive resistance offered by capacitor,after finding resistance this value will follow ohm's law to finding current i.e V=IR. where value of 'c' is in Farad.(here c=105K i.e 1uf)
c) Electrolytic Capacitor - Capacitor having polarity and used for filtering the dc.
d) Diodes - 1N4007 is used which can withstand upto 1000 Volts and rectifies upto 1 Ampere current.
e) Resistance - 1 watt resistance are used . For safety of circuit the wattage of resistance should be more than 60% of the voltage drop across it. So these never heats up.
f) Bulb housing - You can use damaged cfl housing or purchase online.
g) Heat Sink - For long operating life of led ,this compound is used below the led's for heat sink . It is very cheaper.
Glitters, Scrap Paper and OHP sheets(used as projector sheet) are optional.
Step 2: Circuit and Making
Follow the circuit very carefully as tiny mistake will lead to short circuit or shock.
Try to solder the components as close as you can so as to fit in the Bulb Housing.
The soldering of the SMD led's are time consuming if you are a newbie like me. After soldering apply heat sink paste on back side of led .
If you wants to add more led then simply increase the value of electrolytic capacitor which is connected in parallel on output side. (This is also known as polar capacitor)
Then fit it with right polarity and enjoy your work.