Provides information and reviews of electronics and electrical products, including computers, audio and video electronics, fiber optics, electronic components, RF and microwave electronics, security and alarm products, sensors and detectors, lightings and lamps, digital cameras, camcorders, cell phone, battery, printers and copiers, power supplies, optoelectronics, cables and connectors, and satellite communication products.
|
|
Monday, 16 October 2006 |
|
A motion detector is an electronic device that detects the physical movement in a given area and transforms motion into an electric signal. Motion sensors are used in a wide variety of applications and as a result many different types of motion sensors are available. Motion detectors are mainly used in for security systems. A passive infrared motion detection system detects heat energy radiated or emitted by an object. Infrared motion detector devices are often used in automatic light switches and security systems to turn on a light or to activate some other form of alarm or warning indicator when a person or motor vehicle enters a monitored area. Radar motion detectors emit a continuous wave microwave signal and compare the emitted and echo frequencies to produce a beat frequency. |
|
Read more...
|
|
|
Sunday, 15 October 2006 |
|
The single lens reflex (SLR) camera is a type of highly developed and popular camera which uses a hinged mirror to reflect the image formed by the lens onto a viewing screen until exposure. A single lens reflex camera generally consists of an optical system comprised of an objective lens, a pivoted movable mirror to reflect an inverted image upward to a viewing screen, and optics (a pentaprism) to erect the inverted image and direct it to an eyepiece. With the advance of digitization of cameras in recent years, digital cameras have become widely used instead of cameras using silver-halide films. A digital SLR camera combines the advantage of an image processing function, which is unique to digital cameras, with the advantage of the optical system being free from parallax error, which is unique to SLR cameras. |
|
Read more...
|
|
|
Sunday, 15 October 2006 |
|
Flat panel monitors employ technologies such as thin film transistor (TFT) LCD, organic light emitting diode (OLED), plasma display panel (PDP), and field emission display (FED) to display image. The flat panel display receives image signals and horizontal and vertical synchronizing signals. The received image signals are synchronized by the flat panel display according to the horizontal and vertical synchronizing signals and displayed. An LCD monitor displays images by a refractive index difference utilizing optical anisotropy properties of a liquid crystal material. The principle of operation of a plasma flat panel display is the conversion of ultraviolet radiation into visible light by phosphors. Vacuum fluorescent displays utilize thermal emission of electrons from a cathode and phosphor excitation. |
|
Read more...
|
|
|
Sunday, 15 October 2006 |
|
Image projection devices such as liquid crystal display (LCD) projectors, digital light processing (DLP) projectors, film projectors, slide projectors, and overhead projectors are used to project an image onto a surface. A digital light projector (DLP) includes a digital mirror device (DMD) that receives a demanded image to produce a video image that is projected onto a screen. The deformable mirror device is a monolithic single-chip integrated circuit spatial light modulator (SLM), comprised of a high density array of micron square movable micromirrors on micron centers. The digital micromirror device chip functions as a reflective digital optical switch, which can precisely control the light. DLP projectors have high brightness, accurate tone reproduction, quick response time, thin and light composition. |
|
Read more...
|
|
|
Saturday, 14 October 2006 |
|
Computer cables are used for transferring information between computers and other electrical systems. In a personal computer, cable assemblies are used for many purposes including power distribution, low speed signal communication, and high speed signal communication. A typical computer includes a plurality of input and output cables coupled to a back panel of the server, including power cables, data cables, communication lines, and keyboard lines, etc. Cables are used to connect the monitor, printer, speakers and input devices to the processor housing. Typical cables used for cabling computer components are made up of a plurality of electrical conductors. A universal aerial bus (USB) cable is used to electrically connect a computer and other peripherals such as keyboard, mouse, and printer. |
|
Read more...
|
|
|
Saturday, 14 October 2006 |
|
Batteries are classified into primary batteries and secondary batteries or rechargeable batteries. Batteries which are not rechargeable are generally referred to as primary batteries while ones capable of discharge and recharge by being provided with electricity from other electric powers are referred to as secondary batteries or rechargeable batteries. Present rechargeable battery systems can be classified into two groups those employing liquid electrolytes and those employing solid electrolytes. Examples of liquid electrolyte rechargeable battery systems include lead-acid, nickel cadmium, and nickel-metal hydride systems. Rechargeable lithium batteries produce electric energy by an oxidation and reduction reaction during the intercalation and deintercalation of lithium ions. |
|
Read more...
|
|
|
Saturday, 14 October 2006 |
|
A cable television (CATV) system distributes video signals from one head end to subscribers' television receivers via optical fiber cables. A cable modem is a device which allows high speed data accesses to the internet via the CATV network at speeds much faster than that of a telephone modem. Cable modem systems include head ends or cable modem termination system (CMTS) devices that engage in bidirectional communication with the various subscribers' cable modems. In the cable modem system, both television service and digital communication service can be provided to a member via the same cable. Cable modems transmit and receive digital signals at radio frequencies. Digital data on upstream and downstream channels of the cable network is carried over RF carrier signals. |
|
Read more...
|
|
|
|
<< Start < Prev 11 12 13 14 15 16 17 18 19 Next > End >>
|
| Results 205 - 221 of 322 |
Electronics Information
