Making a simple mains LED decorative lamp. скачать в хорошем качестве

Making a simple mains LED decorative lamp.

I've now added this as a project on my website at http://www.bigclive.com/diyled.htm It's basically a super simple mains powered decorative LED lamp that has super simple circuitry and runs at VERY low power. Just quarter of a watt. It uses a simple resistive dropper and discrete four diode rectifier to apply current limited DC to a series string of LEDs. The current is very low at about 1mA for 230/240V and 2mA for 110/120V. The resistors are common quarter watt ones, and two are used as a safety feature and to keep individual resistor heat dissipation low. The diodes are common 1N4007's but you could use 1N4004/5/6 or 7's depending on what you can find easily. The LEDs I used were just random ones from my junk box, and I deliberately mixed alternate warm and cold white LEDs with a scattering of other colours for variety. You can use any standard small LED with the ideal type being the Xmas light style side emitting ones. I converted standard lensed ones to side emitting by "cracking the ice" on them. (clipping off the end of the lens to leave a rough surface on the resin). The light is mounted into a standard lamp base taking precautions to ensure the circuitry in the base is adequately insulated, and a plastic (or glass) bottle of suitable neck and body size can be glued into the base to form the globe. It's worth mentioning that the simplicity of the circuitry and the low current means that if the lamp is plugged into a ceiling or wall light on its own the LEDs may glow dimly even when the switch is turned off. This is because capacitive coupling across the switch wires may pass the few microamps required to light the LEDs. It doesn't indicate a fault in the wiring.