Amazing Artificial LED Candle

The Akafugu LED Candle is an artificial candle that imitates the flickering of a real candle. Use it in place of a real tea candle: It will fit inside a tea candle casing or any holder made for tea candles.

Features:

• Randomly flickering LED: Imitates a candle
• Fits inside a tea candle casing
• Open Source Firmware (available at GitHub)
• Open Source Hardware: Eagle PCB design files available at GitHub
• On-board ISP header for upgrading firmware

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LED Chaser Circuit

Description

I dont know why, but people like blinking lights. You see LED chasers everywhere, in TV shows (Knight Rider), movies, and store windows. This schematic is my version of a simple 10 LED chaser. There is no 555 timer used because at my local electronics store they are over $4 Cdn. Instead, an oscillator made up of two sections of a 4011 NAND gate is employed. This chip is very inexpensive and extremely common.

Circuit Diagram

Parts:
R1 1 Meg 1/4W Resistor
R2 100K Pot
R3 1K 1/4W Resistor or 220Ohm if using blue LEDs
C1 0.1uF 16V Ceramic Disk Capacitor
U1 4011 CMOS NAND Gate
U2 4017 CMOS Counter
LED1-10 LEDs Of Any Colour
MISC Board, Sockets For ICs, Knob For R2

Notes:
1. Use R2 to adjust the "chase rate".
2. You may need to use a lower value resistor if you wish to use blue LEDs. Try 220 Ohm.
3. You can also use incandescent lamps instead of LEDs. Use transistors to drive them by connecting the base of the transistors to each of the outputs of the 4017 through a 1K resistor. Connect one end of the lamp to the positive supply. Then connect the other end to the collector of the transistor. The emitter then goes to ground. Depending on the lamps, you may need power transistors that are heat sinked.
4. C1 may be replaced with a larger value for a slower "chase rate".
5. If you have problems with weird circuit behavior, try replacing R1 with a 33K resistor, and increasing C1 to 1uF.
6. If you plan to use this circuit in your car, be warned that in some areas it is illegal to have red, blue or yellow flashing lights unless you are an emergency vehicle.

 Source: http://www.aaroncake.net

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STMicroelectronics exceeded the limits of LED camera flash

STMicroelectronics (referred to as ST) will allow for compact digital cameras and smart phones to meet the user to improve the built-in flash output power requirements, while supporting the more advanced user control.

STMicroelectronics new chip STCF04 of a built-in flash / best LED flashlight, dual-mode camera flash controllers, LED flash module maximum power from today, generally a few watts of power designed to improve more than 40W, the issue of outdoor security floodlights level brightness. The new product offers more flash and flashlight brightness control feature, the flash mode has 8 user-selectable brightness, LED flashlight mode 12 user-selectable brightness, and a light sensor input. The controller chip built-in flash and torch safety timer, temperature sensor and short circuit protection.

STCF04 STMicroelectronics unique architectural design, integration of a super capacitor, a high-current MOSFET switching of discrete devices and multi-branch high-power white LED light, is the ideal choice for high brightness emergency flash and the camera and camera phone flash.

MOSFET discrete devices STCF04 of power than similar products key, because the other brands of controllers only integration of a power MOSFET. The new product design alternative to traditional high-power xenon flash (to xenon flash) with LED flash, to meet the requirements of todays high-pixel camera sensor, the higher light, but also has the advantages of compact design and simple.

STMicroelectronics has begun to the two major partners Murata (of MURATA) and OSRAM provides STCF04 sample. Murata Manufacturing Co., a market leader in the super capacitor manufacturers, Osram is the worlds leading supplier of flash module of the smartphone, the two companies have begun to show the latest products using the chip.

STCF04 main features:

Maximum flash power> 40W

Torch-mode current (the torch current): 1 x 320mA

100mA Red LED privacy indicator light output; 12 adjustment

Address optional I2C bus

Temperature sensing, short circuit shut down, overvoltage protection and security features of flash / flashlight mode timer

STCF04 TFBGA package 3 x 3mm, 25-ball has been available for sampling. Is expected to begin volume production in the first quarter of 2012.

More LED items: 12 volt LED lights and others.

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Horseshoe Magnetic LED Night Light

Xinhua Ming design this LED magnetic night-light was inspired from symbol of luck horseshoe, the shape brings a freshness to the stone bedside lamp. One end of it is equipped with a built-in battery charger plug the other end is a USB connector, in addition to providing power to the lights, but also it can charge mobile phones and other digital products by the USB connector.Are you still looking for the bright night light, get it!!

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LED Flasher for RC Planes

This is so useful circuit for Rc lovers.Because you can use this circuit simply for your Rc plane or RC car.Here I have used common IC NE 555.So easily you can find it.

Note

* This circuit operates with 6V power supply.

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LED FLASHER WITH ONE TRANSISTOR

This is a unique flasher circuit employing a single driver transistor that takes its flash-rate from a flashing LED. The flasher within the photo is 3mm. An ordinary LED wont work. The flash rate can not be altered by the brightness of the high-bright white LED will be adjusted by altering the 1k resistor across the 100u electrolytic to 4k7 or 10k. The 1k resistor discharges the 100u in order that when the transistor activates, the charging current into the 100u illuminates the white

LED.
If a 10k discharge resistor is used, the 100u isnt absolutely discharged and therefore the LED doesnt flash as bright. All the components within the photo are within the same places as within the circuit diagram to make it simple to envision how the components are connected.

The circuit uses a flashing LED to flash a super-bright 20,000mcd white LED

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Build LED Light Pen Schematic

Physicians and repair engineers often use small light pens for visual examination purposes. Rugged and expensive as these pens may be, their weak point is the bulb, which is a ‘serviceable’ part. In practice, that nearly always equates to ‘expensive’ and / or ‘impossible to find’ when you need one.

LEDs have a much longer life than bulbs and the latest ultra bright white ones also offer higher energy-to-light conversion efficiency. On the down side, LEDs require a small electronic helper circuit called ‘constant-current source’ to get the most out of them.
 
LED Light Pen Circuit Diagram


Here, T1 and R1 switch on the LED. R2 acts as a current sensor with T2 shunting off (most of) T1’s base bias current when the voltage developed across R2 exceeds about 0.65 V. The constant current through the white LED is calculated from

R2 = 0.65 / ILED
With some skill the complete circuit can be built such that its size is equal to an AA battery. The four button cells take the place of the other AA battery that used to be inside the light pen. Link

Author: Myo Min – Copyright: Elektor

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LED Driver Circuit Delivers Constant Luminosity

This is a design of LED driver circuit. This circuit is work with based on 2two transistor. This is the figure of the design circuit.


The operation of the circuit is begin from the output current is almost constant over an input-voltage range of 1.2 to 1.5V and is insensitive to variations of transistor gain. Transistors Q1 and Q2 form an astable flip-flop.R1 and C define the on-time of Q2. During that time, Q1 is off, and the voltage at the base of Q1 and the current in inductor L ramp up. When the voltage at the base of Q1 reaches approximately 0.6V, Q1 turns on, and Q2 turns off. This switching causes “fly back” action in inductor L. The voltage across the inductor reverses, and the energy stored in the inductor transfers to the LED in the form of a down-ramping pulse of current. During fly back time, voltage across the LED is approximately constant. The voltage for yellow and white LEDs is approximately 1.9 and 3.5V, respectively. When the current through the LED falls to zero, the voltage at the collector of Q2 falls sharply, and this circuit condition triggers the next cycle

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