|
Petoscope
A Petoscope is an optoelectronic device for detecting small, distant objects such as flying aircraft. The design, as described in 1936, consisted of an instrument with two parallel light paths. In each path was a collimating objective lens, a screen marked with many small, alternating opaque and transparent squares in a chequerboard pattern, and a second concentrating lens focused on a photocell. The two screens were inverted with respect to each other. This caused a small object in the instrument's field of view to produce differing signals in the two photocells, while a large object affected both light paths equally. The difference between the two signals was amplified and used to raise an alarm. At the beginning of World War II, the device was adapted for use in proximity fuses for bombs. The inventor was Alan S. Fitzgerald of Wynnewood, Pennsylvania, U.S.A., a Research Associate in Electrical Engineering at Swarthmore College Swarthmore College ( , ) is a Private colleg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proximity Fuse
A proximity fuze (or fuse) is a Fuze (munitions), fuze that detonates an Explosive material, explosive device automatically when the distance to the target becomes smaller than a predetermined value. Proximity fuzes are designed for targets such as planes, missiles, ships at sea, and ground forces. They provide a more sophisticated trigger mechanism than the common contact fuze or timed fuze. It is estimated that it increases the lethality by 5 to 10 times, compared to these other fuzes. Background Before the invention of the proximity fuze, detonation was induced by direct contact, a timer set at launch or an altimeter. All of these earlier methods have disadvantages. The probability of a direct hit on a small moving target is low; a shell that just misses the target will not explode. A time- or height-triggered fuze requires good prediction by the gunner and accurate timing by the fuze. If either is wrong, then even accurately aimed shells may explode harmlessly before reaching ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optoelectronic
Optoelectronics (or optronics) is the study and application of electronic devices and systems that find, detect and control light, usually considered a sub-field of photonics. In this context, ''light'' often includes invisible forms of radiation such as gamma rays, X-rays, ultraviolet and infrared, in addition to visible light. Optoelectronic devices are electrical-to-optical or optical-to-electrical transducers, or instruments that use such devices in their operation. ''Electro-optics'' is often erroneously used as a synonym, but is a wider branch of physics that concerns all interactions between light and electric fields, whether or not they form part of an electronic device. Optoelectronics is based on the quantum mechanical effects of light on electronic materials, especially semiconductors, sometimes in the presence of electric fields. * Photoelectric or photovoltaic effect, used in: ** photodiodes (including solar cells) ** phototransistors ** photomultipliers ** op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Popular Mechanics
''Popular Mechanics'' (sometimes PM or PopMech) is a magazine of popular science and technology, featuring automotive, home, outdoor, electronics, science, do-it-yourself, and technology topics. Military topics, aviation and transportation of all types, space, tools and gadgets are commonly featured. It was founded in 1902 by Henry Haven Windsor, who was the editor and—as owner of the Popular Mechanics Company—the publisher. For decades, the tagline of the monthly magazine was "Written so you can understand it." In 1958, PM was purchased by the Hearst Corporation, now Hearst Communications. In 2013, the US edition changed from twelve to ten issues per year, and in 2014 the tagline was changed to "How your world works." The magazine added a podcast in recent years, including regular features ''Most Useful Podcast Ever'' and ''How Your World Works''. History ''Popular Mechanics'' was founded in Chicago by Henry Haven Windsor, with the first issue dated January 11, 1902. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Objective Lens
In optical engineering, the objective is the optical element that gathers light from the object being observed and Focus (optics), focuses the ray (optics), light rays to produce a real image. Objectives can be a single Lens (optics), lens or mirror, or combinations of several optical elements. They are used in microscopes, binoculars, telescopes, cameras, slide projectors, CD players and many other optical instruments. Objectives are also called object lenses, object glasses, or objective glasses. Microscope objectives The objective lens of a microscope is the one at the bottom near the sample. At its simplest, it is a very high-powered magnifying glass, with very short focal length. This is brought very close to the specimen being examined so that the light from the specimen comes to a focus inside the microscope tube. The objective itself is usually a cylinder containing one or more lenses that are typically made of glass; its function is to collect light from the sample. Magn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photocell
Photodetectors, also called photosensors, are sensors of light or other electromagnetic radiation. There is a wide variety of photodetectors which may be classified by mechanism of detection, such as photoelectric or photochemical effects, or by various performance metrics, such as spectral response. Semiconductor-based photodetectors typically photo detector have a p–n junction that converts light photons into current. The absorbed photons make electron–hole pairs in the depletion region. Photodiodes and photo transistors are a few examples of photo detectors. Solar cells convert some of the light energy absorbed into electrical energy. Types Photodetectors may be classified by their mechanism for detection: * Photoemission or photoelectric effect: Photons cause electrons to transition from the conduction band of a material to free electrons in a vacuum or gas. * Thermal: Photons cause electrons to transition to mid-gap states then decay back to lower bands, inducing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wireless Engineer
Wireless communication (or just wireless, when the context allows) is the transfer of information between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most common wireless technologies use radio waves. With radio waves, intended distances can be short, such as a few meters for Bluetooth or as far as millions of kilometers for deep-space radio communications. It encompasses various types of fixed, mobile, and portable applications, including two-way radios, cellular telephones, personal digital assistants (PDAs), and wireless networking. Other examples of applications of radio ''wireless technology'' include GPS units, garage door openers, wireless computer mouse, keyboards and headsets, headphones, radio receivers, satellite television, broadcast television and cordless telephones. Somewhat less common methods of achieving wireless communications involve other electromagnetic phenomena, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USPTO
The United States Patent and Trademark Office (USPTO) is an agency in the U.S. Department of Commerce that serves as the national patent office and trademark registration authority for the United States. The USPTO's headquarters are in Alexandria, Virginia, after a 2005 move from the Crystal City area of neighboring Arlington, Virginia. The USPTO is "unique among federal agencies because it operates solely on fees collected by its users, and not on taxpayer dollars". Its "operating structure is like a business in that it receives requests for services—applications for patents and trademark registrations—and charges fees projected to cover the cost of performing the services tprovide . The Office is headed by the Under Secretary of Commerce for Intellectual Property and Director of the United States Patent and Trademark Office, a position last held by Andrei Iancu until he left office on January 20, 2021. Commissioner of Patents Drew Hirshfeld is performing the funct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swarthmore College
Swarthmore College ( , ) is a Private college, private Liberal arts colleges in the United States, liberal arts college in Swarthmore, Pennsylvania. Founded in 1864, with its first classes held in 1869, Swarthmore is one of the earliest coeducational colleges in the United States. It was established as a college "under the care of Quakers, Friends, [and] at which an education may be obtained equal to that of the best institutions of learning in our country." By 1906, Swarthmore had dropped its religious affiliation and officially became non-sectarian. Swarthmore is a member of the Tri-College Consortium, a cooperative academic arrangement with Bryn Mawr College, Bryn Mawr and Haverford College. Swarthmore also is affiliated with the University of Pennsylvania through the Quaker Consortium, which allows for students to cross-register for classes at all four institutions. Swarthmore offers over 600 courses per year in more than 40 areas of study, including an ABET-accredited engin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Proximity Fuse")
