An LED produces light when current flows through it. The LED will have a rated current specified by the manufacturer. The current can be 2 mA for some of the smaller ones, 150 mA for the ones in most LED flashlights, up to 500 mA for some of the elements in LED traffic lights.
Some background: In order to conduct current, there must be at least a certain voltage across the LED. This is its "forward voltage." Evendiodes that don't emit visible light have the same requirement for a forward voltage before they conduct. Neither type of diode will conduct much current (or emit light) below that voltage, or if the voltage is reversed. Typical values for LEDs are 2V for red, 2.6V for green and 3.5V for white.
Too much reverse voltage across, or too much forward current through, a diode will damage it.
A very common method of lighting an LED is to connect a resistor in series and connect a voltage source, such as a battery, across them. The resistor helps limit the current through the diode and minimize the effect of variations in supply voltage and LED specification variability.
Some other notes:
Driving multiple LEDs in parallel from a single voltage source requires a resistor in series with each LED to compensate for the variations in forward voltage among LEDs.
Pulse width modulation (PWM) can be used to vary the brightness of an LED.
The application of an electric charge to the LED causes the electrons of the applied charge to excite the atoms in a semi-conductive material within the LED that then produces photons in the wavelength of visible light.
LEDs are more efficient than traditional light bulbs as they produce far less heat.
Traditional bulbs contain an element that heats up when a current is passed through it, becoming incandescent. This is terribly inefficient as light is essentially a by-product of the heated element, and much of the energy is wasted. In an LED, however, light is the primary radiated energy, and the transparent materials in the LED's construction allow that light to escape with very little being absorbed and lost as heat.
An LED is a semiconductor diode. It consists of a chip of semiconducting material treated to create a structure called a p-n (positive-negative) junction. When connected to a power source, current flows from the p-side or anode to the n-side, or cathode, but not in the reverse direction. Charge-carriers (electrons and electron holes) flow into the junction from electrodes. When an electron meets a hole, it falls into a lower energy level, and releases energy in the form of a photon (light).
A red LED, for example, has inside it a P-N junction of Gallium Nitride (a semiconductor). When a current is passed through this, electrons in the junction are excited and diffuse from the N-type into the P-type. As they "jump the gap" they release a photon, this is where light is emitted.
A light-emitting diode (LED) is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting. Introduced as a practical electronic component in 1962, early LEDs emitted low-intensity red light, but modern versions are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness.
When a light-emitting diode is forward-biased (switched on), electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence and the color of the light (corresponding to the energy of the photon) is determined by the energy gap of the semiconductor. LEDs are often small in area (less than 1 mm2), and integrated optical components may be used to shape its radiation pattern. LEDs present many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved robustness, smaller size, and faster switching. LEDs powerful enough for room lighting are relatively expensive and require more precise current and heat management than compact fluorescent lamp sources of comparable output.
Light-emitting diodes are used in applications as diverse as aviation lighting, automotive lighting, advertising, general lighting, and traffic signals. LEDs have allowed new text, video displays, and sensors to be developed, while their high switching rates are also useful in advanced communications technology. Infrared LEDs are also used in the remote control units of many commercial products including televisions, DVD players, and other domestic appliances.
The application of an electric charge to the LED causes the electrons of the applied charge to excite the atoms in the LED that then produce photons in the wavelength of visible light.
in 1910 french chemist George Claude ran electricity through a tube of gas and produced a colored light that led to the lighting up of advertisement signs
heat is produced
LED bulbs are specially designed for use in tightly sealed housings that can cause the bulb to overheat. LED bulb solution can physically resemble a familiar light bulb and may well match the appearance of a traditional light bulb. There are a number of vintage light bulbs that use LED filaments to mimic the look and feel of old - contemporary - fluorescent bulbs such as the old and modern. Use one type of LED bulbs Mid-power (SMD) LEDs, which are much lighter and more energy efficient than conventional LED luminaires. How to light an LED bulb: How does a standard LED bulb differ from an LED bulb and how does it differ from a conventional bulb? LED bulb gets hot, the heat sink at the bottom of the bulb pulls some of that heat away, but not everything. If the LED lamp is housed in a closed casing, this heat has no chance of sending it straight back into the lamps and condemning it to a slow and agonizing death. LED Retrofit Module is a bracket that can be attached to the current standard housing without replacing the old bulb hood. It includes the LED bulb base, LED light bulbs and their recessed fairing so you don't have to worry about retaining multiple parts. LED lamps are inserted by plugging their base and then into their retrofit module into the factory housing. To install LED housings and panels, you need to buy more than one component for each of your LED retrofits and LED light bulbs.
Light is produced it does not produce. It is produced by the excitement of subatomic particles called photons and propagated by radiation
There is no such thing as and an infra-red LED. Nor will an any LED glow without a power source. That power may come from a solar cell but an LED (Light Emitting Diode) emits light it does not collect light energy.
You nee to give information about the led. Candel power.
LED lights are cool lights. More light is produced per watt in an LED light, verses an incandescent light. Even more energy can be saved if the light is solar.
in 1910 french chemist George Claude ran electricity through a tube of gas and produced a colored light that led to the lighting up of advertisement signs
in 1910 french chemist George Claude ran electricity through a tube of gas and produced a colored light that led to the lighting up of advertisement signs
in 1910 french chemist George Claude ran electricity through a tube of gas and produced a colored light that led to the lighting up of advertisement signs
That would be an LED or Light Emitting Diode an LED is a light
LED stands for Light-Emitting Diode.
Light Emitting Diode - LED
A 3 watt led light is not the same as a 45 watt bulb. A led light is a lot brighter.
"Nick Holonyak, 75, invented the LED (light emitting diode) in the 1960s."
Depends. Normally, no. Some suggest that the impure white light produced by LEDs can cause headaches. Also, due to the method of most white LEDs (blue LED coated with yellow reactive phosphor) used to produce the color some have suggested that the LED's blue light might be dangerous (see: blue-light hazard).
LED Light is Toxic to the eyes