https://www.facebook.com/share/r/1MqEUa6oyN/ A bad design that for most control range LEDs are off, then there is some brightness control and then turn a little bit more and you have your LEDs fried. Trying to control LED brightness without series resistor by adjusting voltage going to then is a bad design. The LM317 should have been configured →
The flickering of the LED light bulbs can be a problem for some people and also when making video/film. Some LED light bulbs flicker noticeably when new, some do not flicker noticeably. In home lighting applications, flickering LED lights can be particularly bothersome in areas such as the living room or bedroom where people often →
Here is a look at old KEMO M087 LED tester module (the original M087 is discontinued product but there is a newer different looking M087M product. With the aid of this test module it is made possible to carry out tests with all kinds of light emitting diodes in order to check function, brightness, colour →
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. →