inductance concept
inductor is able to convert electrical energy into magnetic energy stored components. Inductor structure similar to a transformer, but only one winding. The inductor has a certain inductance, only to stop the current changes. If there is no current through the inductor, it prevents the current flowing through it; if there is current flowing through it, the circuit is disconnected, it will attempt to maintain the current constant. Inductor, also known as chokes, reactors, dynamic reactor.
3, counting, display circuit:
The display consists of three LED digital tube, counter by
MC14553 three bit dynamic scan counter as the core. T = 1 ~ s < br /> standard pulse into the MC14553 12 foot, multivibrator generates a
rectangular pulse into the MC14553 11 foot, 11 foot when it is in
high level, 4553 of the 12 foot standard pulse can join , pin 11
is low, the RP, differential, get a positive sharp pulse, the first
to counter reset, at the same time, the 4553 latch release, start
on the standard pulse count, 11 feet and then enter the high level,
the counter and the latch, and 10 feet high, counter data latch,
display in front of count results showed stable, located in the
loop counter for N, then TW = NT or Lx / RLln2 = NT, reasonable
selection of RL or Rc, the display can display Lx micro enjoy
number or Cx leather method, very intuitive, this instrument has a
total of 0 ~ 999 Lx / H and 0 ~ 999mH two Cx file, a total of 0 ~
999pF, 0 ~ 999nF (admittance method 0), 999 ~ F range.
Two, the key points of producing
The key element is the range resistance RL and Rc, Omega 1.443
Omega 0.693 and two Resistors can be used high strength enamelLED
wire to wire winding, preferably in the bridge for proofing, ensure
the precision of 1%. Other range resistance can be multiple
Resistors in series and parallel, also should ensure the precision
of 1%.
In three, the debugging
The adjustment circuit is very simple, only needs to adjust the
standard C2 pulse frequency can 1MHz, later without the use of
zero.
The circuit is only using 3 digital tube display, but can display
six digits. If there is a 47312pF Capacitor, in the pF
file show only 732pF, shifting to nF file, the display shows the
004nF, so the measured capacitance for 004732pF 4.732nF, which is
0.04732 ~ F. Inductance measuring the same. Very convenient.
January 27, 2012
takeaway English how to say?
takeaway the “takeaway food” or simply “takeaway”.
If you say “point of take-away” and others, can be said Would you prefer to order out? restaurant, the waiter asked, “or to go” could simply say “For here or to go?” out meal to eat out. For example, the “I used to eat out when I lived alone around the campus.” I have a person living near the school often went out for dinner.
2, light rail how to say in English?
light rail precisely, you can use “light rail”, “Light, Rail Transit,” the short. U.S. teacher Ashley tells us that life without light rail, while direct and simply say that the subway or train, the latter more. For example: I on the train right now I am on the light rail.
3, maglev: maglev
maglev maglev train picture
4, giveaways English argument.
gifts generally said to be the giveaway, and its English explanation is that “something given away free”. Note that the gifts into gift or present, after all the gifts and gifts of great difference.
5, attendance and absenteeism rates of English expression.
attendance: attendance rate;
absenteeism rate: the absence rate.
6 Junsao how to say in English?
Junsao word belongs to the Chinese word formation, and its corresponding English saying so often in the U.S. media expression: army wife.
,
If you speak often intentionally or unintentionally interrupted, “Let me finish, this expression: Bear with me and others.
8. HI-FI, WI-FI, Sci-FI means:
HI-FI is the abbreviation of High Fidelity, the meaning of “fidelity”;
with WI-FI wireless network called
is mainly used in the 802.11b protocol;
Sci-FI, science fiction mean, all known as “Science Fiction”;
< br /> For example: Sci-fi film sci-fi film; Sci-fi story science fiction.
9, four of Shanghai gold: medical insurance, pension insurance, unemployment insurance, housing fund of the English expression:
medical insurance: medical care insurance
old-age insurance: unemployment insurance, endowment insurance
: unemployment insurance
housing fund: housing fund
10, cliches and superficial:
the
stereotyped can be: scratching the surface of the cut-and-dried words.
general: eyewash
11 altitude sickness: altitude sickness
< br /> 12, an invoice: the invoice; receipts: receipt.
October 29, 2011
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It also might be a good idea to carry a coldpack and an Ace bandage or other flexible support with you in your gear bag to aid in any ankle or wrist twists that may happen during your adventure. Slipping on wet grass or leaves, or turning holding your airsoft rifle incorrectly for a prolonged period of time can have quite an impact on certain body parts. Airsoft Gun Safety and First Aid: Play Safe!
Common sense reminds us to know our bodies when heading out for a safe day of airsoft. If you have weak ankles, Cheap Groom Wear Shirt, be sure to wear the proper footwear and ankle support for a long day on your feet. If you e prone to back pain, a back brace or other support will help to keep you comfortable and pain free while you spend some relaxing time practicing the latest maneuvers and tactics in the realm of airsoft guns. But the most important of all safety tips is to wear your protective gear like gloves and other body coverings. Always use your protective eyewear according to the manufacturer instructions, as eye injuries can be some of the most painful of all. If your eye ruptures, beach bridal gowns, there is a good chance that you will lose your eyesight permanently, wedding gown online, so don t try to “look cool” by skipping protective eyewear! No matter how safe a game or sport is, the fact still remains that there just no such thing as a pastime that guaranteed to be accident (or incident) free. This holds true for bike riding, jogging, baseball, and even airsoft guns. But just like everything else, Designer Dresses Women, if you use the proper safety techniques, are aware of some of the basic mishaps and carry a suitable first aid kit, cheap Groom Tie, you l be able to enjoy a worryfree day of airsoft fun. First on our list of safety topics is the allimportant first aid kit. While most of the major playing fields and areas will have a substantial kit or a medical professional available, you might want to consider the possibility of injury when you e well out of range of the base. For this reason and many others, you should always carry a personalsized first aid kit. Most discount retailers, Wedding Accessories wholesale, convenience stores and pharmacies carry the “readymade” kits for you to grab and go, or you can make your own for a lot less money. It needs to be the right size to carry with you at all times, but also needs to hold the essentials like waterproof bandaids, tiffany blue bridesmaid dresses, eyewash pods (to get dust and other tiny, foreign objects out of eyes), Tylenol or Advil, wound dressing, wound disinfecting spray and medical tape. Remember that you l want to treat a small cut or abrasion early on before it gets infected and becomes a real problem. Related themes article:
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October 8, 2011
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Synopsis: Tang Caifeng (also named as Tang Xiaoyan) left home very early. She has muddled in the society for many years, but evertying doesn go on well with her.This winter , she came back her hometown in North East China alone, She thought to have a happy reunion Chinese New Year with her eighty years old father: Old Man Tang Chinese New Year eve is coming soon, and Old Man Tang sons and daughters had also come back home to reunion happily. But they didn keep the happy scene for long, they began to quarelle a lot and finally left home one by one, only leaving Old Man Tang alone, waiting for death by himself In the shattered winter, old man Tang tells his lifestory fragmentarily In this winter, it snowed a lot, some eyewash was told, some dim memory of past revolution was picked up …… It is such a ridiculously cold winter. In the end, Tang Caifeng left home again, she has an unpredictable future waiting for her Resume and Award: 2011 The 5th Cinema Digital Seoul_Film Festival – Special Mention 2011 The 35th HongKong International Film Festival – Humanitarian Awards For Documentaries 2010 The 15th Pusan ??International Film Festival – Asian Cinema Fund (ACF) 2010 MIDA Filmmaker Plan “Asian” Category Selected Proposal award.
Information of Documentary” Shattered “: Film Title: Shattered Screenwriter: Xu Tong Director: Xu Tong Cinematographer: Xu Tong Film editing: Xu Tong Length: 100 mins Year: March, 2011 Type: Documentary Country: China Language: Chinese (mandarin) Subtitle: Chinese / English Color: color black and white Sound: Stereo Format: HDCAM / Digital-Beta Signal system: Pal Screening format: 16:9 Projection speed: 25 / s
Synopsis:
Tangcai Feng (also known as Tang Xiaoyan) away from home, mix in the community for many years; the end all she was not liking. That winter, she is still alone, back home in the Northeast, wondering and her 80-year-old father – Laotang head, have a reunion years.
stalk under the sons and daughters of Laotang head full of joy came back; but did not last long, noisy, as set out birds and animals – like dispersed to dropped Laotang first, lonely waiting for their dying day.
In this fragmented winter Laotang head intermittently tells the story of his life …
this winter, there are a lot of snow; a lot of wild jokes ; there is a distant dull red memory …… chilly; ridiculous …
end the Tang Caifeng again uprooted. Future is uncertain.
award-winning screenings experience:
2011 5th Seoul Digital Film Festival – Special Prize
2011 35th Hong Kong International Film Festival – Humanitarian Awards for Documentaries unit
2010 – Asian fund
2010 won the 15th Pusan ??International Film Festival the 16th Shanghai Television Festival – MIDA director plan the “winning proposal”
 the
documentary.” Laotang head “movie information: < strong>
Title: “Laotang head
screenwriter: Xu Tong
Director: Xu Tong
Photo: Xu Tong
clip: Xu Tong
Length: 100 minutes
Year: March 2011
Type: Documentary
country: Chinese mainland
language: Chinese (Mandarin)
subtitles: Chinese \ English
color: color black and white
sound: stereo
format: of HDCAM / Digital-Beta
standard: PAL
Aspect Ratio: 16:9 Frame rate: 25 / s
< br />
February 22, 2011
semiconductor
refers to a conductive semiconductor can be controlled, ranging from insulators to conductors between the materials. In terms of technological or economic development perspective, the importance of semiconductors is very large. Today, most electronic products, such as computers, mobile phones or digital Recorder and Player are among the core unit and the semiconductor has a very closely connected. Common semiconductor materials are silicon, germanium, gallium arsenide, but silicon is a variety of semiconductor materials in commercial applications in the most influential one.
by selective semiconductor join other “impurities” (three to five elements) to control. If we are in a pure silicon doped (doping) a little arsenic or phosphorus (five outermost electrons), it will be more of a free electron, so that the formation of N-type semiconductor; if we are a little mixed in pure silicon boron (the outermost of three electrons), on the contrary, one less electron, to form a hole (hole), so that the formation of P-type semiconductor (one less negatively charged electrons, can be regarded as a more positive charge).
N-type semiconductor
mixed with a small amount of phosphorus impurity elements (or Sb) in silicon (or germanium crystals), because the semiconductor atoms (such as silicon atoms) are replaced by impurity atoms, phosphorus atoms of the five outer electrons of the outer four with the surrounding semiconductor atoms form a covalent bond, more of an electronic almost unfettered, free electrons are more likely to become . Thus, N-type semiconductor becomes a semiconductor with high electron concentration, the conductivity is mainly due to free-electron conductivity.
P-type semiconductor
mixed with a small amount of impurity boron (or indium element) of the silicon (or germanium crystals), because the semiconductor atoms (such as silicon atoms) are replaced by impurity atoms, the outer layer of the three boron atoms the outer electrons with the surrounding boron atoms form a covalent bond when, will produce a “hole”, this hole may attract the bound electrons to “fill “making boron atoms become negatively charged ions. This type of semiconductor because it contains a higher concentration of “holes” (“equivalent to” positive charge), can become conductive material.
PN junction
one side of the doped P-type semiconductor into the other side of the doped N-type semiconductor into the middle of the two connected contact surface is called the PN junction (English: pn junction). PN junction is electronic technology, many components such as semiconductor diodes, transistors of the material basis. In 1948, William Shockley paper “in a semiconductor PN junction and PN junction transistor theory” at Bell Labs internal publications. Shockley, published in 1950, “the electrons and holes in semiconductors,” to discuss in detail the principle of end-type transistor with John Bardeen, Walter terbutaline La Dayton invented the common point-contact transistor used in different the theory.
Semiconductor also because the applied electric field on the change of its dynamic changes. Semiconductor materials because of this characteristic, it is suitable for use as circuit elements, such as transistors. The transistor is active (active) semiconductors (active semiconductor devices), when the active components and passive (passive) semiconductor devices (passive semiconductor devices) such as resistors (resistor) or capacitor (capacitor) when combined , can be used to design a wide range of integrated circuit products, such as a microprocessor.
When the electrons from the conduction band fall back to the valence band, reducing the energy may be released in the form of light. This process is to create light-emitting diode (light-emitting diode, LED) and semiconductor laser (semiconductor laser) based in the commercial application has a pivotal position. The contrary, the semiconductor can absorb photons through the photoelectric effect and stimulate the valence band electrons, generate electrical signals. This is a light detector (photodetector) sources in fiber-optic communications (fiber-optic communications) or solar cell (solar cell) area is the most important component.
It was found that the semiconductor device can function vacuum tubes , and the mid-20th century, advances in semiconductor manufacturing technology, making the integrated circuits possible. Compared to manual assembly of circuits using discrete electronic components, integrated large number of transistors into a small micro-chip, is a huge step forward. Scale production of integrated circuits, reliability, modular approach to circuit design ensured the rapid adoption of standardized IC design using discrete transistors instead. IC for discrete transistor has two major advantages: cost and performance. Low cost is due to chip all the components through photolithography techniques, printed as a unit, rather than just a time to make a transistor. High performance is due to fast switching components, consume less energy, because the components are small and close to each other. In 2006, the chip size from a few square millimeters to 350 mm?, Per mm? Can reach one million transistors.
is the most advanced integrated circuit microprocessor, or “cores”, can control computers to cell phones to digital microwave everything. Memory and other integrated circuit ASIC family are examples of the modern information society is very important. Although a complex integrated circuit design and development costs are very high, but when the spread is usually millions of products, minimizing the cost of each IC. IC performance is high, because the small size brings a short path, making the low-power logic applications in fast switching speed.
in the computer before, but also appeared to gears, axles and lever-based mechanical computer. The famous Renaissance artist and scientist Leonardo da Vinci had done a similar design, but the manufacturing technology of that era behind this design simply can not afford to put into practice. Computer central processing unit on the experience from vacuum tubes to transistors and then later discrete TTL integrated circuits several important stages. Overnight if the microprocessor era has arrived. Three companies, three programs, almost invariably become a pioneer in the microprocessor industry. Which is Intel Intel 4004, Texas Instruments TMS 1000 and 盖瑞特艾雷赛奇 (Garrett AiResearch) Ministry of Industry CADC (Central Air Data Computer).
1968 年 Garrett was invited to participate in the development of a digital computer, the same is being developed for the U.S. Navy F- 14 Tomcat fighter aircraft flight control computer main competition in the motor system. The MOS-based chipset technology, the CPU core design is completed in 1970, and to a smaller size and higher reliability defeated based on the motor system design, was used in all the early Tomcat fighter. But today it seems, knew CADC and the MP944 chipset, not many people, mainly because the U.S. Navy that this technology is too advanced and not allow the public the details of its design, this situation continued until 1997.
Texas Instruments developed to pre-programmed embedded applications (pre-programmed embedded applications) primarily 4-bit microprocessor technology, TMS 1000, and on September 17, 1971, codenamed TMS1802NC version of the market for the production of single-chip calculator. Intel 4004 plan by the ephod Rick Law Gold (Federico Faggin) presided over the development, and on November 15, 1971 release. Texas Instruments filed a patent for the microprocessor. September 4, 1973 Gary Boone received a single-chip microprocessor of U.S. patent number is 3,757,306. But we may be unable to determine which company actually made the first microprocessor in the laboratory.
According to MIT published the “History of modern computing,” No. 200-221, San Antonio, with Intel, a company called Computer Terminal (later renamed the number of points the company) signed a contract, cooperation design a chip for the terminal. Points later decided not to this chip, and Intel will be named as 8008, and in April 1972 sale. This is the world first 8-bit microprocessors, but also later, “Radio Electronics” magazine prestigious Mark -8 to sell the main components of a computer. 8008 and its successor of 8080 created the microprocessor market.
very successful in the market in the Intel 8080 and Zilog Z80, and a host of other 8-bit microprocessor has been introduced. Originally designed by Motorola 6800 Motorola group of people left the company, another company formed MOS Technology in 6800 and introduction of improved technology based on the product 6502, to 80 in the 20th century with the Z80 microprocessor market rival. Z80 and 6502 chips are designed to reduce overall system cost, for developers to use a reduced scale, to simplify the bus, merger-specific chips (such as the Z80 includes a memory controller on the other methods. These measures led to the 1980s Early home computer “revolution”: consumers with $ 99 can buy a half a computer available.
Intel went a different way, because there is no minicomputer can be simulated, 8080 to expand their approach to design a 16-bit 8086, which is the dominant PC chip was almost the first member of x86 family, Intel introduced the 8086 makes the 8080 economic migration software can reuse business success than expected. Then they released the Intel 80186, 80286, and in 1985 introduced 32-bit 80386, which are forward-compatible processor, Intel created the PC market dominance. integrated memory manager of Intel microprocessors companies such as the development of diesel Scholz, U.S. patent No. 4442484.
world first single-chip 32-bit microprocessor is AT
April 3, 2011
Design of a Time-of-Flight Range-Finder Mark D. McNeill, Lawrence Williams, and HuaMeng Chu Department Electrical Engineering Bucknell University Lewisburg, PA 17837 Abstract -Described is the extension of an ongoing research project to build a pulsed time-of-flight (TOF) laser radar device for use in measuring moderately close objects. Although laser based range-finders do not represent a new area of ??research, they provide an excellent opportunity for undergraduates to enter the area of ??optoelectronic and electronic system design. In this paper we show how such a project can be realized by presenting technical and non-technical obstacles that are specifically related to design in the context of an educational experience. This electrical engineering senior design project allows a team of two students to develop useful teamwork skills in addition to providing a rewarding design and research experience. The goals of the project are to design, build and test a pulsed transmitter, optoelectronic receiver, and time to voltage converter (TVC). The final system will be a single standalone device designed for both technical and non-technical users. We have targeted an observance distance in the 15 to 75 meter range. Our system uses a laser pulse round trip time of flight to determine the distance a target is away from the observer. The system will be portable and temperature compensated for operation between 50 ° F and 80 ° F. This device is designed for application in the recreational bow-hunting area.
Introduction
This work derived from a collaboration between Bucknell University, the Small Business Development Center (SBDC), the Ben Franklin Technology Center (BFTC), and Rightnour Manufacturing Company. At the beginning of December 1997, Professor McNeill met with representatives from Rightenour Manufacturing, the SBDC, and the BFTC about the possibility of designing a small, compact range-finder for the archery and bow hunting recreational sports industry. We initiated a feasibility study to better understand existing technology for range-finders. In consultation with the collaborative partners, we reached agreement to build a prototype of a possible marketable device by January 1999. At this point, Mark McNeill suggested using the project as a senior design experience for students. Bucknell received notification from the SBDC that the project was funded through the BTFC program by mid-February. At this time two senior students came on board and was given the task of designing a prototype for the laser based range-finder by the end of the semester. The professor attracted these students by advertising the project to the entire 26-student class. Senior Design students at Bucknell normally choose the professor with whom they want to work and are encouraged to work in teams of two to four.
Rightnour Manufacturing and the BTFC funded the project through a competitive grant awarded by the state of Pennsylvania for the purpose of increasing joint partnerships between industry and universities. Rightnour manufacturing is a 23-employee company located in Mingoville, Pennsylvania. It manufactures and sells hunting supplies for Bow-Hunting and archery industries. BFTC is funded by the Pennsylvania Department of Community and Economic Development to help strengthen the high technology component of the state economy. The Ben Franklin Partnership unites public, private and educational resources to help small-to-medium sized businesses develop and commercialize new products and processes with the potential for significant job growth in the state. Funds from the BFTC were matched by contributions from Rightenour manufacturing and Bucknell University through cash, in-kind materials and equipment.
The educational objective of this project was to give students an opportunity to design a system for a real customer. We used this as a chance to have students work alongside industry to assist in writing requirements and constraints for the proposed system. Our desire was to have students experience a complete design cycle with the customer so that he / she may see more than just the technical aspects of the process. Specifically, students had a chance to meet directly with the customer, to have direct input into the project scope, and to present orally their chosen design directions. In addition to working directly with the customer, students had the educational benefit of working with a design methodology. This proved useful when obstacles presented themselves. Lastly, as with many design experiences, much was gained by having the students work closely together as a team.
The technical objective of this project was to design and build a compact range-finder that is capable of measuring distances between 15 and 75 meters. Our aim was to provide users of Bow systems with accurate yardage measurements to the target. Often when approaching a target one has difficulty estimating his / her exact distance from the target, thus range- finders are often used to pinpoint a target. At the time we began this project, no laser based range-finders were on the market specifically designed for this distance. Bushnell, a manufacturer of recreational devices, has since placed a system on the market. One of Rightenour early goals was to be the first one to place a system on the market.
The pulsed time-of flight (TOF) laser range-finding technique is a mature technology and has been incorporated into many distance measurement applications [1-3]. A basic device consists of a pulsed laser transmitter, a receiver channel for start and stop pulses, and a time interval measurement unit. The receiver channel includes a photodetector, a preamplifier and a timing discriminator unit . The receiver produces logic level pulses for the time-interval measurement unit.
This paper presents our attempt at achieving such a device while working in the confines of a university system. Specifically, we discuss the educational objectives and benefits for the students who participated in this collaborative project. We stress how a project like this enhances the educational experience of undergraduates. Next we give an overview of our design by presenting the major building blocks of a TOF based range-finder. Following this section, we provide the current status of the project and discuss some of the refinements being implemented by the current senior design students working on the project. Lastly, we reflect on the successes and failures of the collaborative effort and provide a summary of our experiences.
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