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Bogey Value
In manufacturers' specifications for electronic devices, a bogey device (or bogie device) - especially a vacuum tube- is one that has all characteristics equal to the published values, in other words that its parameters all lie in the centre of their bell curve distributions. Parameter value A bogey is a published value for a parameter of an electronic component, such as a vacuum tube A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied. The type known as ..., that is average or typical of devices that will be sold, and which the device's manufacturer is attempting to achieve. With manufacturing tolerances and variables in production, most devices produced do not exactly meet the bogey value for each parameter. Apart from a bogey device being a ''theoretical'' device that has the given characteristics, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum Tube
A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied. The type known as a thermionic tube or thermionic valve utilizes thermionic emission of electrons from a hot cathode for fundamental electronic functions such as signal amplification and current rectification. Non-thermionic types such as a vacuum phototube, however, achieve electron emission through the photoelectric effect, and are used for such purposes as the detection of light intensities. In both types, the electrons are accelerated from the cathode to the anode by the electric field in the tube. The simplest vacuum tube, the diode (i.e. Fleming valve), invented in 1904 by John Ambrose Fleming, contains only a heated electron-emitting cathode and an anode. Electrons can only flow in one direction through the device—from the cathode to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Normal Distribution
In statistics, a normal distribution or Gaussian distribution is a type of continuous probability distribution for a real-valued random variable. The general form of its probability density function is : f(x) = \frac e^ The parameter \mu is the mean or expectation of the distribution (and also its median and mode), while the parameter \sigma is its standard deviation. The variance of the distribution is \sigma^2. A random variable with a Gaussian distribution is said to be normally distributed, and is called a normal deviate. Normal distributions are important in statistics and are often used in the natural and social sciences to represent real-valued random variables whose distributions are not known. Their importance is partly due to the central limit theorem. It states that, under some conditions, the average of many samples (observations) of a random variable with finite mean and variance is itself a random variable—whose distribution converges to a normal d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tube Tester
A tube tester is an electronic instrument designed to test certain characteristics of vacuum tubes (thermionic valves). Tube testers evolved along with the vacuum tube to satisfy the demands of the time, and their evolution ended with the tube era. The first tube testers were simple units designed for specific tubes to be used in the battlefields of World War I by radio operators, so they could easily test the tubes of their communication equipment. Types of tube testers Modern testers The most modern testers perform a multitude of the below tests and are fully automated. Examples of modern testers include the Amplitrex AT1000, the Space-Tech Lab EasyTubeTester, the Maxi pre-amp tester and the maxi-matcher (power tubes only) by maxi test and the new, and somewhat more primitive, DIVO VT1000 by Orange Amplification. While the AT1000, EasyTubeTester and the Maxi-test brand testers offer precise measurements of transconductance/Gm and emissions/iP at full or near full voltages, the O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
