all about led lamp technical: Learn how to make a LED bulb in 3 minutes

LED lamps are energy efficient and have long life, etc., and gradually accepted by people! At this point, I introduce LED energy-saving lamps production making process, I hope you can not only make a LED bulb, but also save your electric bill.

This figure has given the principle schematic I make this time.
The LED bulb use 220 v power supply, the 220 v alternating current (ac) after C1 step-down capacitance then step-down by C2 again, after the whole bridge rectifier filter and the current limiting resistor R3 provide series of 38 LED constant current power supply. The Rated current of the LED is 20 mA, But when we in the production of energy-saving lamps we need to consider the influence of many factors on the LED, Including the problem of luminous decay and heat. When we are doing this kind of lamp, the installation of the LED density is higher, the heat is not easy out. Temperature of the LED light is a great influence to brightness decay and the life of LED bulb. If heat dissipation is not good then will easy to produce light failure, because of the temperature rise the LED current will increase. In a high power lighting, heat dissipation is one of the most important problem which Will affect the stability of the LED lamp.

R1 is a protective resistor in the figure, R2 is the resistance of the capacitor C1 discharge unloading, R3 is a current limiting resistor to prevent the voltage rises and the temperature increase of the LED current increases. C2 is the filter capacitor, there is no need to consider the LED filter circuit in the actual circuit. C2 is used to prevent inrush current damage when switched on the LED. Turn on the light there will be a large charging current because of the existence of C1, The current flowing through the LED will produce damage to the LED. With the intervention of C2, turn on the light of the charging current is completely absorbed by the C2 to impact protection when turn on the light. This circuit is the most practical circuit, occupy small space can be easily installed in a small lamp cup, lamp cup products are now widely adopted. Advantages: constant current source, power consumption, small size, economical and practical. However, in the design of the buck capacitor voltage needs more than 400V polyester capacitor or CBB capacitor, and resistant to more than pressure 250v if use filter capacitor. This circuit is suitable for driving 20-40 pieces of LED(20mA).