High Power Led Display | Electronic Project Circuits

Posts Tagged ‘high power led display’

Mains Powered White LED Lamp

Did it ever occur to you that an array of white LEDs can be used as a small lamp for the living room? If not, read on. LED lamps are available ready-made, look exactly the same as standard halogen lamps and can be fitted in a standard 230-V light fitting. We opened one, and as expected, a capacitor has been used to drop the voltage from 230 V to the voltage suitable for the LEDs. This method is cheaper and smaller compared to using a transformer. The lamp uses only 1 watt and therefore also gives off less light than, say, a 20 W halogen lamp. The light is also somewhat bluer. The circuit operates in the following manner: C1 behaves as a voltage dropping ‘resistor’ and ensures that the current is not too high (about 12 mA).
The bridge rectifier turns the AC voltage into a DC voltage. LEDs can only operate from a DC voltage. They will even fail when the negative voltage is greater then 5 V. The electrolytic capacitor has a double function: it ensures that there is sufficient voltage to light the LEDs when the mains voltage is less than the forward voltage of the LEDs and it takes care of the inrush current peak that occurs when the mains is switched on. This current pulse could otherwise damage the LEDs. Then there is the 560-ohm resistor, it ensures that the current through the LED is more constant and therefore the light output is more uniform. ..
Source link:http://www.extremecircuits.net/2010/07/mains-powered-white-led-lamp.html

Be the first to comment - What do you think? Posted by admin - May 4, 2011 at 8:10 am

Categories: LED Flasher, Lighting Tags: high power led display, led display ac current

Race Start Lights by PIC16F684

This project provides an simple F1 motor racing style 5 light race start sequence with a random delay that you can use on a real race track, kart circuit or even your slot-car circuit. Operation is simple; when the start button is pressed all the LED clusters are off. They then illuminate sequentially at one second intervals until all five LED clusters are on. After a random interval between 1 and about 7 seconds the LEDs extinguish, signalling the start of the race. Once the LEDs have extinguished simply press the start button again to initiate another race start sequence.
Read Source: http://picprojects.org.uk/projects/

Be the first to comment - What do you think? Posted by admin - May 30, 2009 at 9:48 am

Categories: LED Flasher, Lighting, Microcontroller Tags: high power led display, led display sign

1.2V Drive 7 High efficiency white LED flashlight

High efficiency white LEDs have advanced to the point where they can replace glow bulbs and other light sources not only as indicators, but also for illumination. While many of the claims made about the LEDs’ efficiency, light quality, lifetime and economy are mostly exaggeration, the truth is that for very low light levels they are now competitive. They have equal or slightly higher efficiency than a flashlight bulb, a longer lifetime, and are very much tougher. On the other hand, they are still far more expensive than a bulb, for a given light output.

The circuit is a self-oscillating boost converter, and I certainly cannot claim having invented it. It is ages old! I only did the detail design of this one, and optimized it in the course of one afternoon. It runs with a beautifully clean waveform, with all components except the LEDs staying completely cold to the touch. At this low power level, even that doesn’t guarantee a good efficiency, but I measured it at about 72%, which is quite good for a circuit operating from such a low voltage!

Source :http://ludens.cl/Electron/ledlamp/ledlamp.html
Thank you.