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Preferred Numbers
In industrial design, preferred numbers (also called preferred values or preferred series) are standard guidelines for choosing exact product dimensions within a given set of constraints. Product developers must choose numerous lengths, distances, diameters, volumes, and other characteristic quantities. While all of these choices are constrained by considerations of functionality, usability, compatibility, safety or cost, there usually remains considerable leeway in the ''exact'' choice for many dimensions. Preferred numbers serve two purposes: # Using them increases the probability of compatibility between objects designed at different times by different people. In other words, it is one tactic among many in standardization, whether within a company or within an industry, and it is usually desirable in industrial contexts (unless the goal is vendor lock-in or planned obsolescence) # They are chosen such that when a product is manufactured in many different sizes, these will en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Renard Series
Renard series are a system of preferred numbers dividing an interval from 1 to 10 into 5, 10, 20, or 40 steps. This set of preferred numbers was proposed in 1877 by French army engineer Colonel Charles Renard. His system was adopted by the ISO in 1949 to form the ISO Recommendation R3, first published in 1953 or 1954, which evolved into the international standard ISO 3. The factor between two consecutive numbers in a Renard series is approximately constant (before rounding), namely the 5th, 10th, 20th, or 40th root of 10 (approximately 1.58, 1.26, 1.12, and 1.06, respectively), which leads to a geometric sequence. This way, the maximum relative error is minimized if an arbitrary number is replaced by the nearest Renard number multiplied by the appropriate power of 10. One application of the Renard series of numbers is to current rating of electric fuses. Another common use is the voltage rating of capacitors (e.g. 100 V, 160 V, 250 V, 400 V, 630 V). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Renard
Charles Renard (1847–1905) born in Damblain, Vosges, was a French military engineer. Airships After the Franco-Prussian War of 1870-1871 he started work on the design of airships at the French army aeronautical department. Together with Arthur C. Krebs and his brother Paul, in 1884 he constructed '' La France'', which made its maiden flight on 9 August 1884 at Chalais-Meudon, making a 23-minute circular flight. This was the first time that a flying machine made a flight which returned to the place of take-off. It was later exhibited at the Paris Exposition Universelle (1889). Preferred numbers He also proposed a now widely used system of preferred numbers known as Renard numbers that was later named after him and became international standard ISO 3. It helped the French army to reduce the number of different balloon ropes kept on inventory from 425 to 17. Road Train Colonel Renard invented the Renard Road Train first developed by Darracq and displayed by them in 1903 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Industrial Design
Industrial design is a process of design applied to physical Product (business), products that are to be manufactured by mass production. It is the creative act of determining and defining a product's form and features, which takes place in advance of the manufacture or production of the product. It consists purely of repeated, often automated, replication, while craft-based design is a process or approach in which the form of the product is determined by the product's creator largely concurrent with the act of its production. All manufactured products are the result of a design process, but the nature of this process can vary. It can be conducted by an individual or a team, and such a team could include people with varied expertise (e.g. designers, engineers, business experts, etc.). It can emphasize intuitive creativity or calculated Evidence-based design, scientific decision-making, and often emphasizes a mix of both. It can be influenced by factors as varied as Raw material, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
E96 Series (preferred Numbers)
The E series is a system of preferred numbers (also called preferred values) derived for use in electronic components. It consists of the E3, E6, E12, E24, E48, E96 and E192 series, where the number after the 'E' designates the quantity of logarithmic value "steps" per decade. Although it is theoretically possible to produce components of any value, in practice the need for inventory simplification has led the industry to settle on the E series for resistors, capacitors, inductors, and zener diodes. Other types of electrical components are either specified by the Renard series (for example fuses) or are defined in relevant product standards (for example IEC 60228 for wires). History During the Golden Age of Radio (1920s to 1950s), numerous companies manufactured AM radio receivers for consumer use. In the early years, many components were not standardized between radio manufacturers. The capacitance values of capacitors (previously called condensers) and resista ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euro
The euro ( symbol: €; code: EUR) is the official currency of 19 out of the member states of the European Union (EU). This group of states is known as the eurozone or, officially, the euro area, and includes about 340 million citizens . The euro is divided into 100 cents. The currency is also used officially by the institutions of the European Union, by four European microstates that are not EU members, the British Overseas Territory of Akrotiri and Dhekelia, as well as unilaterally by Montenegro and Kosovo. Outside Europe, a number of special territories of EU members also use the euro as their currency. Additionally, over 200 million people worldwide use currencies pegged to the euro. As of 2013, the euro is the second-largest reserve currency as well as the second-most traded currency in the world after the United States dollar. , with more than €1.3 trillion in circulation, the euro has one of the highest combined values of banknotes and coins in c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Currency
A currency, "in circulation", from la, currens, -entis, literally meaning "running" or "traversing" is a standardization of money in any form, in use or circulation as a medium of exchange, for example banknotes and coins. A more general definition is that a currency is a ''system of money'' in common use within a specific environment over time, especially for people in a nation state. Under this definition, the British Pound Sterling (£), euros (€), Japanese yen (¥), and U.S. dollars (US$)) are examples of (government-issued) fiat currencies. Currencies may act as stores of value and be traded between nations in foreign exchange markets, which determine the relative values of the different currencies. Currencies in this sense are either chosen by users or decreed by governments, and each type has limited boundaries of acceptance - i.e. legal tender laws may require a particular unit of account for payments to government agencies. Other definitions of the term "curren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denomination (currency)
Denomination is a proper description of a currency amount, usually for coins or banknotes. Denominations may also be used with other means of payment such as gift cards. For example, ''five euros'' is the denomination of a five-euro note. Subunit and super unit In a currency, there is usually a main unit (base) and a subunit that is a fraction of the main unit. In some countries, there are multiple levels of subunits. In the former Ottoman Empire, 1 lira = 100 kuruş = 4000 para = 12000 akçe. Today, only a few places have more than one subunit, notably the Jordanian dinar is divided into 10 dirham, 100 qirsh/piastres, or 1000 fils. Many countries where Western European languages are spoken currently have their main units divided into 100 subunits. Some currencies that previously had subunits no longer do, because inflation has rendered the subunit useless. A prominent example is the Japanese yen, which was formerly divided into 100 sen or 1000 rin. Both subunits were demone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oscilloscope
An oscilloscope (informally a scope) is a type of electronic test instrument that graphically displays varying electrical voltages as a two-dimensional plot of one or more signals as a function of time. The main purposes are to display repetitive or single waveforms on the screen that would otherwise occur too briefly to be perceived by the human eye. The displayed waveform can then be analyzed for properties such as amplitude, frequency, rise time, time interval, distortion, and others. Originally, calculation of these values required manually measuring the waveform against the scales built into the screen of the instrument. Modern digital instruments may calculate and display these properties directly. Oscilloscopes are used in the sciences, medicine, engineering, automotive and the telecommunications industry. General-purpose instruments are used for maintenance of electronic equipment and laboratory work. Special-purpose oscilloscopes may be used to analyze an automotive ign ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Standard
international standard is a technical standard developed by one or more international standards organizations. International standards are available for consideration and use worldwide. The most prominent such organization is the International Organization for Standardization (ISO). Other prominent international standards organizations including the International Telecommunication Union (ITU) and the International Electrotechnical Commission (IEC). Together, these three organizations have formed the World Standards Cooperation alliance. Purpose International standards may be used either by direct application or by a process of modifying an international standard to suit local conditions. Adopting international standards results in creating national standards that are equivalent, or substantially the same as international standards in technical content, but may have (i) editorial differences as to appearance, use of symbols and measurement units, substitution of a point for a com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decade (log Scale)
One decade (symbol dec) is a unit for measuring ratios on a logarithmic scale, with one decade corresponding to a ratio of 10 between two numbers. Example: Scientific notation When a real number like .007 is denoted alternatively by 7. × 10—3 then it is said that the number is represented in scientific notation. More generally, to write a number in the form ''a'' × 10''b'', where 1 < ''a'' < 10 and ''b'' is an , is to express it in , and ''a'' is called the ''significand'' or the ''mantissa'', and ''b'' is its |
IEC 60228
IEC 60228 is the International Electrotechnical Commission (IEC)'s international standard on ''conductors of insulated cables''. the current version is Third Edition 2004-11 Among other things, it defines a set of standard wire cross-sectional areas: In engineering applications, it is often most convenient to describe a wire in terms of its cross-section area, rather than its diameter, because the cross section is directly proportional to its strength and weight, and inversely proportional to its resistance. The cross-sectional area is also related to the maximum current that a wire can carry safely. This document is one considered ''fundamental'' in that it does not contain reference to any other standard. Description The document describes several aspects of the conductors for electrical cables Class This refers to the flexibility and thermal effects i.e temperature of a conductor. * Class 1: Solid conductor * Class 2: Stranded conductor intended for fixed installation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronics
The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification and rectification, which distinguishes it from classical electrical engineering, which only uses passive effects such as resistance, capacitance and inductance to control electric current flow. Electronics has hugely influenced the development of modern society. The central driving force behind the entire electronics industry is the semiconductor industry sector, which has annual sales of over $481 billion as of 2018. The largest industry sector is e-commerce, which generated over $29 trillion in 2017. History and development Electronics has hugely influenced the development of modern society. The identification of the electron in 1897, along with the subsequent invention of the vacuum tube which could amplify and rectify small ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
