I saw a quite interesting looking waveform from a 10W LED floodlight powered from 230V AC. It looks like when AC voltage waveform instantaneous voltage lower than some voltage, it takes practucally no current and above it it looks like a constant current load. This is picture of the light. This looks like this uses →
Here is maybe simplest power over Ethernet (PoE) powered LED Christmas light. This circuit provides powering of LED light string from IEEE 803.2af compatible standard power supply. On the up there is the IEEE 802.3af PoE power supply that feeds 48V DC power to RJ-45 connector when it detects a PoE needing device connected. I →
I saw an advertisement video of LED hat on Facebook some days ago. This kind of had might not be the best idea to wear on many parties, but maybe could have some uses for advertisement purposes. This kind of LED hat is something that makes hacker mind spinning. The hat had wireless connection so, →
Traditionally, an optical communication system would require two components at each end: transmitter and receiver. It has been known that LEDs can act as photo sensors, but they have not been very practical for optical communications applications. Researchers have now shown switching between LED and photodetector modes on new type component quickly enough for real-time →
While switching to LED lighting certainly helps reduce power consumption, we can do more. Each conventional mains powered LED bulb has its own AC/DC power supply, which is needed for bulbs to be compatible with AC wiring and lighting fixtures with sockets designed 100 years ago. Having individual power supplies adds cost and decreases efficiency →
https://spectrum.ieee.org/energywise/semiconductors/optoelectronics/acpowered-leds-could-cut-the-cost-of-lighting “Engineers at Pennsylvania State University have demonstrated a practical way to integrate gallium nitride LEDs and their power supply circuits onto the same chip using industry-standard manufacturing processes.” The results promise a cheap lighting chip that runs directly from the AC electricity supplied by a wall outlet (110-120V AC). Researchers say that this makes →
I had some broked LED flashlights and I thought of using components from them. Especially the compact battery holder that takes three AAA batteries looks useful in other small projects. Those worked OK when lightly loaded. But when I started taking current for a small motor, I could not get acceptable power out of them. →
http://www.southgatearc.org/news/2018/october/led-lighting-can-disrupt-radio-communications.htm#.W9XAslNyg0M Dutch amateur radio society VERON reports the current EMC standard, developed in the last century, no longer suffices. “The faulty LED lights disrupt wireless connections in and around the house. Radiocommunications Agency therefore starts an investigation into 50 LED lamp suppliers.” “A number of lamps do not appear to meet the EMC standard. Especially →
Found this from eBay for about 2 dollars: New Mini Handy 2~150mA LED Tester Test Box for Light-emitting Diode Bulb Lamp Description: 100% brand new and high quality Material: Plastic Color: White Handy device for testing LED’s. Simply plug your LED into the correct holes (all of which are marked) and push the button to →
LED Energie brand LED bulb with following data stopped to work properly: 230V 50Hz 7W E27 450lm 3000K 60mA 20D 3684 Mod.5161 So lets make a tear-down Inside There seems to be 20 small LEDs in series inside bulb and one of them burned black. As such this LED string is expected to need around →