Low cost LED Driver. Start Up Project 22

2ALED Drivers are used to drive High Power LEDs that require more than 100 mA current. A typical 1 watt LED consumes around 100-300 mA current while a 10 watt LED consumes 600 mA to 1 Amps current. So a resistor to drop the current is not sufficient since it heats up when high current passes. Moreover, the high power LEDs require a Constant Current to give steady brightness. So LED Drivers are used for this purpose. A typical LED driver has two sections. An SMPS converts 220V AC to DC and a Constant Current Generator Circuit provides Constant current to LED. But LED Drivers are costly units and the cost range from Rs. 150- Rs.600. We can make a Low cost LED driver just for Rs.15. Try it.
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LED Tube light Repairing. Home Utility Circuit 32

1ALED Tube lights are costly lights but susceptible to instant damage. Since it uses an LED Driver and very sensitive LED Chips, voltage fluctuations, voltage surge, over heating etc can destroy it easily. But all the parts of the LED Tube light will not fail, so that we can easily repair it. The major problem may be the failure of one or more LED chips or the driver. By doing some repair works, we can use the LED Tube light again. I found one of my 12 Watts LED Tube light is not glowing and decided to repair it. Now it is working well. Its expense was just Rs.50 for the driver only. See the step wise method of LED Tube light repairing.
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LED Driver CC Chip .Design Note 40

High current White LED requires constant current for giving maximum brightness. Connecting 1 Watt LED to the DC source using a current limiting resistor gives poor performance and the LED will be either too bright or too dim. More over, the low value resistor (10 Ohm or less) will heat up since the LED consumes around 200 to 350 milli ampere current . So here is a simple LED driver chip AMC 7135 that gives constant current (CC) to LED to give maximum brightness. It also increases the life of LED. It is too simple and enjoy the project.
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