Diodes and triodes.

The English physicist John Ambrose Fleming worked as an engineering consultant for many technology firms of his day, including Edison Telephone; in 1904, as a result of experiments conducted on Edison Effect bulbs imported from the USA and while working as scientific adviser to the Marconi company, he developed a device he called an "oscillation valve" (because it passes current in only one direction) or kenotron, which can also be used as part of a radio wave detector. Later known as the Fleming valve and then the diode, it allowed electrical current to flow in only one direction, enabling the rectification of alternating current. Its operation is described in greater detail in the previous section.

In 1907 Lee De Forest placed a bent wire serving as a screen, later known as the "grid" electrode, between the filament and plate electrode. As the voltage applied to the grid was varied from negative to positive, the number of electrons flowing from the filament to the plate would vary accordingly. Thus the grid was said to electrostatically "control" the plate current. The resulting three-electrode device was therefore an excellent and very sensitive amplifier of voltages. DeForest called his invention the "Audion". In 1907, DeForest filed[2] for a three-electrode version of the Audion for use in radio communications. The device is now known as the triode.
De Forest's device was not strictly a vacuum tube, but clearly depended for its action on ionisation of the relatively high levels of gas remaining after evacuation. The De Forest company, in its Audion leaflets, warned against operation which might cause the vacuum to become too hard. The Finnish inventor Eric Tigerstedt significantly improved on the original triode design in 1914, while working on his sound-on-film process in Berlin, Germany. The first true vacuum triodes were the Pliotrons developed by Irving Langmuir at the General Electric research laboratory (Schenectady, New York) in 1915. Langmuir was one of the first scientists to realize that a harder vacuum would improve the amplifying behaviour of the triode. Pliotrons were closely followed by the French 'R' Type which was in widespread use by the allied military by 1916. These two types were the first true vacuum tubes. Historically, vacuum levels in production vacuum tubes typically ranged between 10 µPa to 10 nPa.
The non-linear operating characteristic of the triode caused early tube audio amplifiers to exhibit harmonic distortions at low volumes. This is not to be confused with the overdrive that tube amplifiers exhibit at high volume levels (known as the tube sound). To remedy the low volume distortion problem, engineers plotted curves of the applied grid voltage and resulting plate currents, and discovered that there was a range of relatively linear operation. In order to use this range, a negative voltage had to be applied to the grid to place the tube in the "middle" of the linear area with no signal applied. This was called the idle condition, and the plate current at this point the "idle current". Today this current would be called the quiescent or standing current. The controlling voltage was superimposed onto this fixed voltage, resulting in linear swings of plate current for both positive and negative swings of the input voltage. This concept was called grid bias.

Write the correct past perfect tense of the verbs in parenthesis, to complete the paraghraphs. Translate.

The English physicist John Ambrose Fleming ________ __________

(work) as an engineering consultant for many technology firms of his

day, including Edison Telephone; in 1904, as a result of experiments

he ________ __________ (conduct) on Edison Effect bulbs

he ________ __________ (import) from the USA and while he

________ __________ (be) working as a scientific adviser

to the Marconi company, he ________ __________

(develop) a device he ________ __________ (call) an "oscillation

valve" (because it passes current in only one direction) or kenotron,

which can also be used as part of a radio wave detector.

Later it ________ __________ (be) known as the Fleming valve and

then the diode, it ________ __________ (allow) electrical current

to flow in only one direction, enabling the rectification of alternating current.

Its operation ________ __________ __________ (be /describe) in greater detail in the

previous section.

Structure of a vacuum tube triode.

In electronics, a vacuum tube, electron tube (in North America), thermionic valve, or just valve (elsewhere, especially in Britain), is a device used to amplify, switch, otherwise modify, or create an electrical signal by controlling the movement of electrons in a low-pressure space, often tubular in form. Many devices called vacuum tubes are filled with low-pressure gas: these are so-called soft valves (or tubes); as distinct from the hard vacuum type, which have the internal gas pressure reduced as far as possible. Almost all depend on the thermal emission of electrons, hence thermionic.
Vacuum tubes were critical to the development of electronics technology, which drove the expansion and commercialization of radio broadcasting, television, radar, high fidelity sound reproduction, large telephone networks, modern types of digital computer, and industrial process control. Some of these applications pre-dated electronics, but it was electronics that made them widespread and practical; electronics have driven mechanical computers such as slide-rules to the point of obsolescence.
For most purposes, the vacuum tube has been replaced by solid-state semiconductor devices such as transistors and solid-state diodes: for most applications, they are smaller, more efficient, more reliable, and cheaper—either as discrete devices or as integrated circuits. However, tubes are still used in specialized applications: for engineering reasons, as in high power radio frequency transmitters; or for their aesthetic appeal, as in modern audio amplification. Cathode ray tubes are still used as display devices in television sets, video monitors, and oscilloscopes, although they are being replaced at various rates by LCDs and other flat-panel displays. A specialized form of the electron tube, the magnetron, is the source of microwave energy in microwave ovens and some radar systems.
A vacuum tube consists of arrangements of electrodes in a vacuum within an insulating, temperature-resistant envelope. Although the envelope is classically glass, power tubes often use ceramic and metal. The electrodes are attached to leads which pass through the envelope via an air tight seal. On most tubes, the leads are designed to plug into a tube socket for easy replacement.

Explanation:
The simplest vacuum tubes resemble incandescent light bulbs in that they have a filament sealed in a glass envelope which has been evacuated of all air. When hot, the filament releases electrons into the vacuum: a process called thermionic emission. The resulting negatively-charged cloud of electrons is called a space charge. These electrons will be drawn to a metal plate inside the envelope, if the plate (also called the anode) is positively charged relative to the filament (or cathode). The result is a flow of electrons from filament to plate. This cannot work in the reverse direction because the plate is not heated and does not emit electrons. This very simple example described can thus be seen to operate as a diode: a device that conducts current only in one direction. The vacuum tube diode conducts conventional current from plate (anode) to the filament (cathode); this is the opposite direction to the flow of electrons (called electron current).
***************************************************************
Answer the questions, based on the dialog above, and translate
the answers. Some answers will be found on the internet.

1. What is a vacuum tube, electron tube?
___________________________________

2. How is the electric signal created?
___________________________________

3. What are vavuum tubes filled with?
___________________________________

4. How are they so-called?
___________________________________

5. How is it distinct from the hard vacuum type?
___________________________________

6. What do all these devises depend on?
___________________________________

7. Vacuum tubes were critical to the development of electronics technology, because they drove the expansion and commercialization of what?
___________________________________

8. What has the vacuum tube been replaced by?
___________________________________

9. Where are Cathode ray tubes are still used as display devices?
___________________________________

10. A specialized form of the electron tube, the magnetron, is still the sourse of what?
___________________________________

11. What do the simplest vacuum tubes resemble?
___________________________________

12. What do they have that makes them resemble light bulbs?
___________________________________

13. What happends when it’s hot, and what does it realease, and how is the process called?
___________________________________

14. What is the resulting negatively-charged cloud of electrons is called?
___________________________________

History of development:

Write the correct present perfect tense of the verbs in parenthesis, to complete the paraghraphs.

The 19th century ______ __________ (saw) increasing research with evacuated tubes, such

as the Geissler and Crookes tubes. Scientists who ______ __________ (enperiment) with

such tubes and ______ __________ (include) Eugen Goldstein, Nikola Tesla, Johann Wilhelm

Hittorf, Thomas Edison, and many others.

Write the correct form of the verb “to be” and change the verbs in parentesis to the past tense to complete the paraghraphs.

These tubes ______ (be) mostly for __________ (specialize) scientific applications, or

______ (be) novelties, with the exception of the light bulb. The groundwork ______

(be) __________ (lay) by these scientists and inventors, however, this ______ (be) critical to

the development of vacuum tube technology.

Though the thermionic emission effect ________ (be) originally __________ (report) in 1873

by Frederick Guthrie, it is Thomas Edison's 1883 investigation of the "Edison Effect" that is more often mentioned.

History of the first Leyden jars.

Answer the questions, based on the internet.

1. What did the ancient Greeks know about rubbing pieces of amber?

___________________________________

2. What is the triboelectric effect,?

___________________________________

3. What is another name gine to the triboelectric effect,?

___________________________________

4. According to what does the polarity and strength of the charges produced differ?

___________________________________

5. What is a dielectric?

___________________________________

6. Who buit a crude friction generator around 1650?

___________________________________

7. What did it consist of?

___________________________________

8. Who found a method of storing large amounts of electric charge and in what year?

___________________________________

9. How was it done?

___________________________________

10. Why did the Kleistian jar go on to be known as the Leyden jar?

___________________________________

11. What does the word “endurance” mean in terms of electricity or electronics?

___________________________________


12. What is it’s formula?

___________________________________

Do You Know Your Electronics? (1)

Find out if you are an electronic whiz or if you completely know nothing at all?

Question 1: What is this? A...
Memory Card
D.A.T.
PSP
Flash Drive
CPU

Question 2: What does PSP stand for?
Park Sand Play
Play Station Playable
Play Station Portable
Portable Station Play
Pan Sand Pack

Question 3: What is this? A...
Ipod Shuffle
PSP
Ipod
RCA
Ipod Nano

Question 4: Which One of these is not a website?
braingle.com
explosm.net
Sandha.com
allthetests.com
Chacha.com

Question 5: Which one of these is not a Cable Company?
Comcast
Zenith
Fandango
Dish Network

Question 6: What is an RCA Cable?
2 Wires. = One red, One yellow,
right corn aerodynamics
A cable company called RCA
3 Wires. = One red, One White, One Yellow

Question 7: If there is a cable that points outward, it is called.
Male
Female
Nacka
Tiger
Wire

Question 8: If there is a wire that doesn't point out, what is it called?
Hard
Lion
Female
Nick
Male

Question 9: What is the name of a computer screen?
Computer
Screen
CPU
Monitor
S.T.N.

Question 10: What is the name of the person who created Microsoft?
Bill Gates
Bill Fameal
Chelsea Heggersten
Sam Sunrise
Benjamin Franklin

Capacitor

A capacitor is an electrical/electronic device that can store energy in the electric field between a pair of conductors (called "plates"). The process of storing energy in the capacitor is known as "charging", and involves electric charges of equal magnitude, but opposite polarity, building up on each plate.
Capacitors are often used in electric and electronic circuits as energy-storage devices. They can also be used to differentiate between high-frequency and low-frequency signals. This property makes them useful in electronic filters.
Capacitors are occasionally referred to as condensers. This is considered an antiquated term in English, but most other languages use an equivalent, like "Kondensator" in German, "Condensador" in Spanish, or "Kondensa" in Japanese.
In October 1745, Ewald Georg von Kleist of Pomerania in Germany invented the first recorded capacitor: a glass jar with water inside as one plate was held on the hand as the other plate. A wire in the mouth of the bottle received charge from an electric machine, and released it as a spark.[1]

In the same year, Dutch physicist Pieter van Musschenbroek independently invented a very similar capacitor. It was named the Leyden jar, after the University of Leyden where van Musschenbroek worked. Daniel Gralath was the first to combine several jars in parallel into a "battery" to increase the total possible stored charge.
Benjamin Franklin investigated the Leyden jar, and proved that the charge was stored on the glass, not in the water as others had assumed. The earliest unit of capacitance was the 'jar', equivalent to about 1 nF.

Early capacitors were also known as condensers, a term that is still occasionally used today. It was coined by Alessandro Volta in 1782 (derived from the Italian condensatore), with reference to the device's ability to store a higher density of electric charge than a normal isolated conductor.
Most non-English European languages still use a word derived from "condensatore".

*********************************************************
Answer the questions, based on the dialog above, and translate the answers.

Some answers will be found on the internet.
_______________________________________

1. What is a capacitor?
_______________________________________

2. What is another name given to conductors?
_______________________________________

3. Give an example of the materials used in conductors?
_______________________________________

4. Why are the materias mentioned in # 3 used?
_______________________________________

5. How is the process of storing energy in the capacitor is known as?
_______________________________________

6. What does this process involve?
_______________________________________

7. What builds up on each plate as a resolt?
_______________________________________

8. How are capacitors often used in electric and electronic circuits?
_______________________________________

9. How can they also be used?
_______________________________________

10. Who invented the first recorded capacitor, in what month & year?
_______________________________________

11. Who invented the Leyden jar?
_______________________________________

12. Who investigated the Leyden jar, and proved that the charge was stored on the glass, not in the water as others had assumed?
_______________________________________

Identifying resistors

A resistor is a two-terminal electrical or electronic component that opposes an electric current by producing a voltage drop between its terminals in accordance with Ohm's law: The electrical resistance is equal to the voltage drop across the resistor divided by the current through the resistor while the temperature remains the same. Resistors are used as part of electrical networks and electronic circuits.

Identifying resistors

Most axial resistors use a pattern of colored stripes to indicate resistance. Surface-mount resistors are marked numerically. Cases are usually brown, blue, or green, though other colors are occasionally found such as dark red or dark grey.
One can also use a multimeter or ohmmeter to test the values of a resistor.

Four-band axial resistors

Main article: Electronic color code
Four-band identification is the most commonly used color coding scheme on all resistors. It consists of four colored bands that are painted around the body of the resistor.
Each color corresponds to a certain number, shown in the chart.

The scheme is simple.

The first two numbers are the first two significant digits of the resistance value, the third is a multiplier, and the fourth is the tolerance of the value. Each color corresponds to a certain number, shown in the chart below. The tolerance for a 4-band resistor will be 1%, 5%, or 10%.

************************************************************

Answer the questions based on the paragraphs above, and translate.
Some answers can be found on the internet.

1. What is a resistor?
________________________________________

2. How does a resistor opose an electric current?
________________________________________

3. Where does a Ohm's law apply to?
________________________________________

4. What does the Ohm's law state?
________________________________________

5. Give the mathematical equation that describes this relationship is:
________________________________________

6. What does the “I” stand for?
________________________________________

7. What does the “V” stand for?
________________________________________

8. What does the “R” stand for?
________________________________________

9. What do Most axial resistors use indicate resistance.
________________________________________

10. How are Surface-mount resistors are marked?
________________________________________

11. What can also be used to test the values of a resistor?
________________________________________

12. Which is the is the most commonly used color coding scheme on all resistors?
________________________________________

13. Describe how the coding scheme is composed?
________________________________________

14. What is the the tolerance for a 4-band resistor?
________________________________________

Electronic circuits.

An electronic circuit is an electrical circuit that also contains active electronic devices such as transistors or vacuum tubes.

Electronic circuits can display highly complex behaviors, even though they are governed by the same laws as simple electrical circuits.

Electronic circuits can usually be categorized as analog, digital, or mixed-signal (a combination of analog and digital) electronic circuits.

Analog circuits

Analog electronic circuits are those in which electric signals vary continuously to correspond to the information being represented. Electronic equipment like voltage amplifiers, power amplifiers, tuning circuits, radios, and televisions are largely analog (with the exception of their control sections, which may be digital, especially in modern units).

The basic units of analog circuits are passive (resistors, capacitors, inductors) and active (independent power sources and dependent power sources). Components such as transistors may be represented by a model containing passive components and dependent sources. Another classification is to take impedance and independent sources and opamp as basic electronic components; this allows us to model frequency dependent negative resistors, gyrators, negative impedance converters, and dependent sources as secondary electronic components.

Digital circuits

In digital electronic circuits, electric signals take on discrete values to represent logical and numeric values that represent the information to be processed. Transistors are used primarily as switches to make logic gates. Examples of electronic equipment which use digital circuits include digital wristwatches, calculators and PDAs, and microprocessors.

Mixed-signal circuits

Mixed-signal or hybrid circuits contain elements of both analog and digital circuits. Examples include comparators, timers, PLLs, ADCs (analog-to-digital converters), and DACs (digital-to-analog converters).

3 Basic Parts

Energy source - converts nonelectric energy into energy, examples are batteries and generators.

Output device - uses electric energy to do work and a connection, examples are motor and lamp.

Connection - allows electric current to flow, examples are wire and cable.

Answer the questions based on the paragraphs above, and translate.

1. Why do Analog electronic circuits vary continuously?
________________________________________

2. Name some electronic equipment that is largely “analog”.
________________________________________

3. Are the control sections of the equipment you named above, also “analog”?
________________________________________

4. How can electronic circuits be categorized?
________________________________________

5. What is an electronic circuit?

________________________________________

6. What does it also contain?

________________________________________

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Write the correct present perfect tense of the verbs in parenthesis, to complete the paraghraphs.

Digital circuits

In digital electronic circuits, electric signals ________ __________ (take) on discrete values to represent logical and numeric values that ________ __________ (represent) the information to be processed. Transistors ________ been __________ (use) primarily as switches to make logic gates. Examples of electronic equipment which ________ __________ (use) digital circuits include digital wristwatches, calculators and PDAs, and microprocessors.

Mixed-signal circuits

Mixed-signal or hybrid circuits ________ __________ (contain) elements of both analog and digital circuits. Examples include comparators, timers, PLLs, ADCs (analog-to-digital converters), and DACs (digital-to-analog converters).

3 Basic Parts

Energy source – ________ __________ (convert) nonelectric energy into energy, examples are batteries and generators.
Output device – ________ __________ (use) electric energy to do work and a connection, examples are motor and lamp.
Connection – ________ __________ (allow) electric current to flow, examples are wire and cable.