Ultraviolet Portable ultraviolet lamp Ultraviolet (UV) light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, that is, in the range between 400 nm and 100 nm, corresponding to photon energies from 3 eV to 124 eV. It is so-named because the spectrum consists of electromagnetic waves with frequencies higher than those that humans identify as the color violet. These frequencies are invisible to most humans except those with aphakia. Near-UV is visible to a number of insects and birds. UV light is found in sunlight and is emitted by electric arcs and specialized lights such as mercury lamps and black lights. Although ultraviolet radiation is invisible to the human eye, most people are aware of the effect it has on the skin of fair-skinned people, i.e., the suntan and sunburn. Discovery Origin of the term The name means "beyond violet" (from Latin ultra, "beyond"), violet being the color of the shortest wavelengths of visible light. Subtypes Sources
LED LED-uri albastre, roşii şi verzi; acestea pot fi combinate pentru a produce orice culoare. Un LED (din engleză light-emitting diode, însemnând diodă emițătoare de lumină) este o diodă semiconductoare ce emite lumină la polarizarea directă a joncțiunii p-n. Efectul este o formă de electroluminescență. Un LED este o sursă de lumină mică, de cele mai multe ori însoțită de un circuit electric ce permite modularea formei radiației luminoase. In anul 2008, cel mai puternic LED comercializat aparținea firmei sud-coreene Seoul Semiconductor[1]. La 12 mai 2010, firma Nexxus Lighting a prezentat cea mai puternica lampă LED de uz casnic disponibilă pe piață, cu o eficiență de 50 Lumen/Watt[2]. La 12 aprilie 2010, firma Toshiba a prezentat prototipul celei mai puternice lămpi LED de uz casnic și industrial, cu o eficiență de 120 Lumen/Watt.[4]. La 18 decembrie 2012, firma Cree a prezentat Lampa LED XLamp MK-R cu o eficiență de 200 Lumen/Watt si cu o dimensiune de 7 x 7 mm.[5].
Diode Closeup of a diode, showing the square-shaped semiconductor crystal (black object on left). Structure of a vacuum tube diode. The filament may be bare, or more commonly (as shown here), embedded within and insulated from an enclosing cathode. Main functions[edit] However, diodes can have more complicated behavior than this simple on–off action, due to their nonlinear current-voltage characteristics. Semiconductor diodes begin conducting electricity only if a certain threshold voltage or cut-in voltage is present in the forward direction (a state in which the diode is said to be forward-biased). History[edit] Vacuum tube diodes[edit] Thomas Edison independently rediscovered the principle on February 13, 1880. Edison devised a circuit where his modified light bulb effectively replaced the resistor in a DC voltmeter. Solid-state diodes[edit] Etymology[edit] At the time of their invention, such devices were known as rectifiers. Rectifiers[edit] Thermionic diodes[edit] Diode vacuum tube construction
LED lights Color changing, and Bluetooth LED accessories Wholesale Electronics, Gadgets, & LED lighting You Will Love When You Order Are you shopping for wholesale electronics, discount gadgets, and LED lights online? How to find cool and trendy gadgets is a bit difficult, but with perseverance and determination eventually you will find some of the best wholesalers of these products. As you all know, many of the best wholesale gadgets are found online. Technology has produced higher quality electronics such as in: mobile phones, media players, game consoles, Bluetooth accessories, and a whole lot more. For people who are asking how to find wholesale electronics distributors and suppliers, here are some helpful tips for you: The first thing that you should do is to conduct a thorough investigation about the wholesaler companies in the electronics manufacturing industry. Communicate with vendors about your orders and about warranties, and refund policies. Then your are ready to place your order.
DigitalReadSerial Learning Examples | Foundations | Hacking | Links Examples > Basics Digital Read Serial This example shows you how to monitor the state of a switch by establishing serial communication between your Arduino and your computer over USB. Hardware Required Arduino Board A momentary switch, button, or toggle switch 10k ohm resistor breadboard hook-up wire Circuit image developed using Fritzing. Connect three wires to the Arduino board. Pushbuttons or switches connect two points in a circuit when you press them. If you disconnect the digital i/o pin from everything, the LED may blink erratically. Schematic Code In the program below, the very first thing that you do will in the setup function is to begin serial communications, at 9600 bits of data per second, between your Arduino and your computer with the line: Serial.begin(9600); Next, initialize digital pin 2, the pin that will read the output from your button, as an input: pinMode(2,INPUT); int sensorValue = digitalRead(2); Serial.println(sensorValue);
Laser diode Top: a packaged laser diode shown with a penny for scale. Bottom: the laser diode chip is removed from the above package and placed on the eye of a needle for scale. A laser diode with the case cut away. A laser diode, or LD, is an electrically pumped semiconductor laser in which the active medium is formed by a p-n junction of a semiconductor diode similar to that found in a light-emitting diode. The laser diode is the most common type of laser produced with a wide range of uses that include, but are not limited to, fiber optic communications, barcode readers, laser pointers, CD/DVD/Blu-ray reading and recording, laser printing, scanning and increasingly directional lighting sources. Theory of operation[edit] Semi-conductor lasers (660 nm, 635 nm, 532 nm, 520 nm, 445 nm, 405 nm) A laser diode is electrically a P-i-n diode. Laser diodes form a subset of the larger classification of semiconductor p-n junction diodes. Diagram of a simple laser diode, such as shown above; not to scale
LED Lighting - LED Lights & Fixtures for the Home Brighten up your home with LED lights LED lights are an energy-efficient, great modern solution in lighting that casts a diffuse, even light that’s crisp yet soft. The even illumination of LED lighting will do away with shadowy recesses in rooms while providing clarity through direct lighting. Types of LED lighting LED spotlights with shelving or cabinet clamp Enjoy glare-free light anywhere with the flexibility of a bendable lamp neck and a clamp that can firmly attach to desks, shelving, headboards or cabinets. LED light strips Flexible lighting strips allow you to express your creativity in lighting. LED lamps Light up even the smallest space in your home and put it to practical use with this super-slim lamp with an adjustable lamp head. LED track lighting Use cabinet spotlights to showcase your piece of art or to make collectibles or cherished family heirlooms come to life. Save with LED light bulbs Frequently asked questions about LED lighting? How much more efficient are LED lights?
PIR Sensor (Rev B) Item code: 555-28027 What It Can Do Detects motion of humans or animals from as far away as 30 feetSilent operation for alarms, motion activated nightlights, holiday propsAutomatically resets after period of inactivity Passive infrared (PIR) sensors detect motion by comparing the amount of infrared radiation that reaches a pair of detectors. The Parallax PIR Motion Sensor has a simple on/off output: when on, the sensor is detecting movement. A selectable jumper on the sensor lets you set working distance: L (for Long) position, the effective sensor distance is up to 30 feet. For proper operation the sensor should be allowed to warm up for 20 to 60 seconds after first applying power. This KickStart is for Rev B of the PIR Motion Sensor. Parts List PIR Motion SensorBASIC Stamp HomeWork Board, Propeller Board of Education, Propeller QuickStart, or Arduino Uno microcontroller22 gauge solid conductor hookup wire Basic Wiring Program KickStarts BASIC Stamp HomeWork Board Propeller BOE Wiring Diagram
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