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Making a user color selection AC powered 220-240v LED lighting. Answered

I want to light my room's ceiling edge with led lights which can change colors using a switch. I am not so good with electronics, except for basic stuff!! SO would like a nice and elaborated guide to build this.



Best Answer 7 years ago

Getting into high voltage is where you run into dangerous problems. I'd recommend a commercial solution.

For what you'd pay to MAKE it, I'd recommend dealextreme: http://www.dealextreme.com/p/rgb-150x5050-smd-led-multicolored-light-strip-5-meter-dc-12v-41523
5 meter long strip that you can change the colours.

I should point out you'll need a suitable 12 volt power supply that can handle 50 or so watts...I'd recommend one of the modded ATX power supplies here on ibles.

The string will operate although it will not be as bright as it would be if you were using DC current. Led's consume D.C to produce light and are generally meant to be operated on D.C. but they will operate on A.C. However with A.C. of equal voltage the value of the current limiting resistor will have to be adjusted to achieve the same brightness. This is because with A.C. the led will only be lit when the current flow is in the proper direction. When the current flow reverses the led blocks current flow and remains unlit. Thus A.C. applied to an led will cause it to blink on and off even though at high enough frequencies it will appear to be lit continuously. To make a blinking led appear as bright as constantly lit led the current limiting resistor's value is lowered to allow more current flow causing the led to be brighter when lit. This causes a greater average light output and thus a brighter appearing led. This trick of the eye is a phenomenon known as persistence of vision. This is also the reason the led appears to be continuously lit when it is actually blinking.
There is an led type specifically meant to be operated on both A.C. and D.C. They are called Tri-color led's and as the name suggests they are capable of producing three distinct colors. They are actually composed of two led's one red and one green, wired cathode to anode and anode to cathode. This arrangement will cause the led to light up red when D.C. of one polarity is applied and green when D.C. of the opposite polarity is applied. The third color is generated by applying A.C. which alternately lights the red and green led's. The rapidly alternating colors mix visually to produce the third color, a greenish yellow. This is the kind of led used in moving dot displays that can change color.

SolidAxle !

Thanks avadhut1001 very informative, but i am looking for something very basic. Thanks again :)