Electronics & Computer Lab

Daftar Mata Kuliah Semester 1

2011-12-29T08:25:00.019+07:00

Daftar Mata kuliah semester 1, Program Studi Teknik Elektronika - Politeknik Negeri Bandung, Tahun ajaran 2008/2009

1. Alat Ukur dan Pengukuran - 2 SKS
2. B.Inggris Teknik 1 - 2 SKS
3. Teknologi Mekanik - 2 SKS
4. Fisika Terapan - 2 SKS
5. Gambar Teknik - 2 SKS
6. K3 dan Hukum Ketenagakerjaan - 2 SKS
7. Komponen Elektronika - 2 SKS
8. Matematika Terapan 1 - 2 SKS
9. Rangkaian Listrik 1 - 2 SKS
10. Rangkaian Logika - 2 SKS

Tahapan Perancangan Elektronika

2011-02-27T17:00:00.014+07:00

Dalam perancangan di bidang teknik elektronika, khususnya pembuatan rangkaian elektronika ada beberapa tahapan yaitu:

Simulasi rangkaian dengan software simulasi rangkaian elektronika,
Pengecekan rangkaian yang sebenarnya dengan protoboard atau breadboard,
Pembuatan rangkaian yang sudah benar pada PCB.

Langkah-langkah diatas adalah langkah-langkah umum yang digunakan oleh kebanyakan pelajar atau orang-orang yang bergelut di bidang teknik elektronika dalam merancang suatu rangkaian elektronika. Dengan langkah-langkah seperti yang telah disebutkan diatas, diharapkan perancangan rangkaian elektronika akan lebih optimal dari segi perancangan dan realisasi (biaya, waktu, dan lain-lain).

Tahapan yang pertama adalah mensimulasikan rangkaian yang akan direalisasikan dengan menggunakan software simulator. Tujuannya adalah untuk mengetahui logik/keadaan rangkaian tanpa harus menyediakan komponen-komponen nyata/aslinya. Jadi, pada simulasi, komponen-komponennya seringnya dalam keadaan ideal. Ada banyak sekali jenis software simulator ini, diantaranya yang pernah penulis gunakan adalah:

Electronics Workbench versi 5.12
Circuit Maker versi 6.0 dan 2000
Proteus versi 7.1

Masing-masing software ini punya kelebihan dan kekurangannya yang insyaallah akan penulis bahas di tulisan selanjutnya.

Tahapan yang kedua adalah mencoba rangkaian hasil simulasi pada protoboard atau breadboard. Tujuannya adalah untuk membandingkan rangkaian bekerja sesuai dengan simulasi atau tidak (tidak harus persis). Protoboard/Breadboard adalah suatu perangkat berbahan plastik (isolator) dengan lubang-lubang untuk menempatkan kaki-kaki komponen, terdapat tembaga dibagian dalamnya dan menghubungkan komponen cukup dengan kawat/kabel tanpa harus disolder (solderless). Jadi apabila ada kesalahan pada rangkaian, maka dapat diperbaiki cukup dengan memindahkan kabel ataupun komponennya. Untuk lebih jelas, dapat dilihat pada gambar dibawah ini.

Sumber gambar : http://simonpstevens.com

Bahasan mengenai protoboard ini insyaallah akan dibahas lebih lanjut pada tulisan berikutnya.

Tahapan yang terakhir adalah merealisasikan rangkaian pada PCB (Printed Circuit Board) atau PRT (Papan Rangkaian Tercetak). Tentu saja, syaratnya adalah rangkaian sudah benar. PCB atau P Ada beberapa teknik dalam merancang PCB, yaitu: dengan manual (menggunakan spidol, setrika, FeCl3) dan semi otomatis (menggunakan software desain PCB, sinar ultraviolet). Software desain PCB dan teknik pembuatan PCB Insyaallah juga akan dibahas pada tulisan selanjutnya.

Sumber : www.google.co.id, http://labdasar.ee.itb.ac.id/lab/EL2195/0910/modul%20praktikum/APENDIKS%20SISDIG.pdf, buku kuliah, dll.

The Current I = V x R

2011-02-09T10:04:00.014+07:00

If we keep the same resistance in a circuit but vary the voltage, the current will vary. The circuit in Fig. 2-1 demonstrates this idea. The applied voltage V can be varied from 0 -12 V, as an example. The bulb has a 12-V filament, which requires this much voltage for its normal current to light with normal intensity. The meter I indicates the amount of current in the circuit for the bulb.

With 12 V applied, the bulb lights, indicating normal current. When V is reduced to 10 V, there is less light because of less I. As V decreases, the bulb becomes dimmer. For zero volts applied there is no current and the bulb cannot light. In summary, the changing brilliance of the bulb shows the current is varying with the changes in applied voltage.

For the general case of any V and R, Ohm's Law is

where I is the amount of current through the resistance R connected across the source of potential difference V. With volts as the practical unit for V and ohms for R, the amount of current I is in amperes. Therefore,

This formula says to simply divide the voltage across R by the ohms of resistance between the two points of potential difference to calculate the amperes of current through R.

Ohm's Law

2011-02-09T09:09:00.007+07:00

This note is explain how the amount of current I in a circuit depends on its resistance R and the applied voltage. Specifically, I = V/R, determined in 1828 by the experiments of George Simon Ohm. If we know any two of the factors V, I, and R, we can calculate the third. As an example, with 6V applied accros an R of 2 ohm, the I is 6/2 = 3 A. Ohm's law also determines the amount of electric power in the circuit. The amount of power consumed P in a circuit is equal to the voltage times the current (P = V x I). The power used by the R above is therefore equal 6 x 3 = 18 W. This relations apply to both DC and AC circuit.

Important terms in this note are:
volt
ampere
ohm
watt
joule
milli
micro
kilo
mega
linear graph
power
voltampere characteristic

Charges of Opposite Polarity Attract

2010-12-25T11:35:00.003+07:00

If two small charged bodies of light weight are mounted so that they are free to move easily and are placed close to each other, one can be attracted to the other when the two charges have opposite polarity. In terms of electrons and protons, they tend to be attracted to each other by the force of attraction between opposite charges. Furthermore, the weight of an electron is only about 1/1840 weight of a proton. As a result, the force of attraction tends to make electrons move to protons.

Negative and Positive Polarities

2010-12-25T11:35:00.001+07:00

Historically, the negative polarity has been assigned to the static charge produced on rubber, amber, and resinous materials in general. Positive polarity refers to the static charge produced on glass and other vitreous materials. On this basis, the electrons in all atoms are basic particles of negative charge because their polarity is the same as the charge on rubber. Protons have positive charge because the polarity is the same as the charge on glass.

The Coulumb Unit of Charge

2010-12-25T11:31:00.002+07:00

If you rub a head rubber pen or comb on a sheet of paper, the rubber will attract a corner of the paper if it is free to move easily. The paper and rubber then give evidence of a static electric charge. The work of rubbing resulted in separating electrons and protons to produce a charge of excess electrons on the surface of the rubber and a charge of excess protons on the paper.

Because paper and rubber are dielectric materials, they hold their extra electrons or protons. As a result, the paper and rubber are no longer neutral, but each has an electric charge. The resultant electric charges provide the force of attraction between the rubber and the paper. This mechanical force of attraction or repulsion between charges is the fundamental method by which electricity makes itself evidence.

Any charge is an example of static electricity because the electrons or protons are not in motion. There are many examples. When you walk across a wool rug, your body becomes charged with an excess of electrons. Similarly, silk, fur, and glass can be rubbed to produce a static charge. This effect is more evident in dry weather, because a moist dielectric does not hold its charge so well. Also, plastic materials can be charged easily, which is why thin, light weight plastics seem to stick to everything.

The charge of many billions of electrons or protons is necessary for common applications of electricity. Therefore, it is convenient to define a practical unit called the coulomb (C) as equal to the charge of 6.25 x 10^18 electrons or protons stored in a dielectric. The analysis of static charge and their forces is called electrostatics.

The symbol for electric charge is Q or q, standing for quantity. For instance, a charge of 6.25 x 10^18 electrons is stated as Q = 1 C. This unit is named after Charles A. Coulomb (1736-1806), a French physicist, who measured the force between charges.

Particles in the Nucleus

2010-12-25T11:14:00.004+07:00

A stable nucleus, which is not radioactive, contains protons and neutrons. A neutron is electrically neutral without any net charge. Its mass is almost the same as a proton.

A proton has the positive charge of a hydrogen nucleus. The charge is the same amount as that of an orbital electron but of opposite polarity. There are no electrons in the nucleus. Table 3 lists the charge and mass for these three basic particles in all atoms.

Subshells

2010-12-25T09:06:00.003+07:00

Although not shown in the illustrations, all the shells except K are divided into subshells. This subdivision accounts for different types of orbits in the same shell. For instance, electrons in one subshell may have elliptical orbits, while other electrons in the same main shell have circular orbits. The subshells indicate magnetic properties of the atom.

Electron Valence

2010-01-07T16:39:00.001+07:00

This value is the number of electrons in an incomplete outermost shell. Copper, for instance, has a valence of 1 because there is 1 electron in the last shell, after the inner shells have been completed with their stable number. Similarly, hydrogen has a valence of 1, and carbon has a valence of 4. The number of outer electrons is considered positive valence, as these electrons are in addition to the stable shells.

Except for H and He, the goal of valence is 8 for all the atoms, as each tends to form the stable structure of 8 electrons in the outside ring. For this reason, valence can also be considered as the number of electron s in the outside ring needed to make 8. This value is the negative valence. As examples, the valence of copper can be considered +1 or -7; carbon has the valence of ±4. The inert gases have a valence of 0, as they all have a complete stable outer shell of 8 electrons.

The valence indicates how easily the atom can gain or lose electrons. For instance, atoms with a valence of +1 can lose this 1 outside electron, especially to atoms with a valence of +7 or -1, which need 1 electron to complete the outside shell with 8 electrons.

Orbital Rings

2009-09-25T13:53:00.000+07:00

Atomic Number

2009-09-21T09:23:00.002+07:00

This gives the number of protons or electrons required in the atom for each element. For the hydrogen atom in Fig. 1, the atomic number is 1, which means the nucleus has 1 proton balanced by 1 orbital electrons. Similarly, the carbon atom in Fig. 2 with atomic number 6 has 6 protons in the nucleus and 6 orbital electrons. Also, the copper atom has 29 electrons because its atomic number is 29.

Structure of the Atom

2009-09-21T09:20:00.001+07:00

Although nobody has ever seen an atom, its hypothetical structure fits experimental evidence that has been measured very exactly. The size and electric charge of the invisible particles in the atom are indicated by how much they are deflected by known forces. Our present planetary model of the atom was proposed by Niels Bohr in 1913. His contribution was joining the new ideas of the nuclear atom developed by Lord Rutherford (1871-1937) with the quantum theory of radiation developed by Max Planck (1858-1947) and Albert Einstein (1879-1955).

The nucleus contains protons for all the positive charge in the atom. The number of protons in the nucleus is equal to the number of planetary electrons. Thus, the positive and negative charges are balanced, as the proton and electron have equal and opposite charges. The orbits for the planetary electrons are also called shells or energy levels.

Molecules and Compounds

2009-09-21T09:16:00.000+07:00

A group of two or more atoms forms a molecule. For instance, two atoms of hydrogen (H) form a hydrogen molecule (H2). When hydrogen unites chemically with oxygen, the result is water (H2O), which is compound. A compound, then consists of two or more elements. The molecule is the smallest unit of a compound with the same chemical characteristic. We can have molecules for either elements or compounds. However, atoms exist only for the elements.

Elements

2009-05-31T18:50:00.002+07:00

The combination of electrons and protons forming stable atomic structures result in different kinds of elementary substance having specific characteristics. A few examples are the elements hydrogen, oxygen, carbon, copper, and iron. An element is defined as substance that cannot be decomposed any further by chemical action. The atom is the smallest particle of an element that still has the same characteristics as the element. Atom itself is a Greek word meaning a particle too small to be subdivided. As an example of the fact that atoms are to small to be visible, a particle of carbon the size of a pinpoint contains many billions of atoms. The electrons and protons within the atom are even smaller.

Table lists some more examples of elements. These are just a few out of a total of 106. Notice how the elements are grouped. The metals listed across the top row are all good conductors of electricity. Each has an atomic structure with an unstable outside ring that allows many free electrons.

The semiconductors have 4 electrons in the outermost ring. This means they neither gain or lose electrons but share them with similar atoms. The reason is that 4 is exactly halfway to the stable condition of 8 electrons in the outside ring.

The inert gases have a complete outside ring of 8 electrons, which makes them chemically inactive. Remember that 8 electrons in the outside ring is a stable structure. An example is neon.

Conductors, Insulators, and Semiconductors

2009-05-31T18:33:00.002+07:00

When electrons can move easily from atom to atom in a material, it is a conductor. In general, all the metals are good conductors, with silver the best and copper second. Their atomic structure allows free movement of the outermost orbital electrons. Copper wire is generally used for practical conductors because it costs much less than silver. The purpose of using conductors is to allow electric current to flow with minimum opposition.

The wire conductor is used only as a means of delivering current produced by the voltage source to a device that needs the current in order to function. As an example, a bulb lights only when current is made to low through the filament.

A material with atoms in which the electrons tend to stay in their own orbits is an insulator because it cannot conduct electricity very easily. However, the insulators are able to hold or store electricity better than the conductors. An insulating material, such as glass, plastic, rubber, paper, air, or mica, is also called a dielectric, meaning it can store electric charge.

Insulators can be useful when it is necessary to prevent current flow. In addition, for applications requiring the storage of electric charge, as in capacitors, a dielectric material must be used because a good conductor cannot store any charge.

Carbon can considered a semiconductor, conducting less than the metal conductors but more the insulators. In the same group are germanium and silicon, which are commonly used for transistors and other semiconductor components.

Electrons and Protons in the Atom

2009-05-26T17:11:00.006+07:00

Although there are many number of posibble methods by which electrons and protons might be grouped, they assemble in specific combinations that result in a stable arrengement. Each stable combination of electrons and protons makes one particular type of atom. Figure 1 illustrates the electron and proton structure of one atom of the gas hydrogen. This atom consists of a central mass called the nucleus and 1 electron outside. The proton in nucleus makes it the massive and stable part of the atom because a proton is 1840 times heavier than electron.

In figure 1, the 1 electron in the hydrogen atom is shown in an orbital ring around the nucleus. In order to account for the electrical stability of atom, we can consider the electron as spinning around the nucleus, as planets revolve around the sun. Then the electrical force attracting the electrons in toward the nucleus is balanced by the mechanical force outward on the rotating electron. As a result, the electron stays in its orbit around the nucleus.

In an atom that has more electrons and protons than hydrogen, all the protons are in the nucleus, while all the electrons are in one or more outside rings. For example, the carbon atom illustrated figure 2a has 6 protons in two outside rings. The total number of electrons in the outside rings must equal the number of protons in the nucleus in a neutral atom.

The distribution of electrons in the orbital rings determines the atom’s electrical stability. Especially important is the number of electrons in the ring farthest from the nucleus. This outermost ring requires 8 electrons for stability, except when there is only one ring, which has a maximum of 2 electrons.

In the carbon atom in fig. 2a, with 6 electrons, there are just 2 electrons in the first ring because 2 is its maximum number. The remaining 4 electrons are in the second ring, which can have a maximum of 8 electrons.

As another example, the copper atom in Fig. 2b has only 1 electron in the last ring, which can include 8 electrons. Therefore, the outside ring of the copper atom is less stable than the outside ring of the carbon atom.

When there are many atoms close together in a copper wire, the outermost orbital electrons are not sure which atoms they belong to. They can migrate easily from ane atom to another at random. Such electrons that can move freely from one atom to the next are often called free electrons. This freedom accounts for the ability of copper to conduct electricity very easily. It is the movement of free electrons that provides electric current in a metal conductor.

The net effect in the wire itself without any applied voltage, however, is zero because of the random motion of the free electrons. When voltage is applied, it forces all the free electrons to move in the same direction to produce electron flow, which is an electric current.

Negative and Positive Polarities

2009-04-30T12:30:00.005+07:00

We see the effects of electricity in a battery, static charge, lightning, radio, television, and many other applications. What do they all have in common that is electrical in nature? The answer is basic particles of electric charge with opposite polarities. All the materials we know, including solids, liquids, and gases, contain two basic particles of electric charge; the electron and proton. An electron is the smallest amount of electric charge having the characteristic called negative polarity. The proton is a basic particle with positive polarity.

Actually, the negative and positive polarities indicate two opposite characteristic that seem to be fundamental in all physical applications. Just magnets have north and south poles. Electric charges have the opposite polarities labeled negative and positive. The opposing characteristics provide a method of balancing one against the other to explain different physical effects.

It is the arrangement of electrons and protons as basic particles of electricity that determines the electrical characteristic of all substances. As an example, the paper has electrons and protons in it. There is no evidence of electricity, though, because the number of electrons equals the number of protons. In that case the opposite electrical forces cancel, making the paper electrically neutral. The neutral condition means that opposing forces are exactly balanced, without any net effect either way.

When we want to use the electrical forces the associated with the negative and positive charges in all matter, work must be done to separate the electrons and protons. Changing the balance of forces produces evidence of electricity. A battery, for instance, can do electrical work because its chemical energy separates electric charges to produce an excess of protons at its positive terminal. With separate and opposite charges at the two terminals, electric energy can be supplied to a circuit connected to the battery.

Electricity

2009-04-01T20:20:00.000+07:00

Electricity is an invisible force that can produce heat, light, motion, and many other physical effects. The force is an attraction or repulsion between electric charges. More specifically, electricity can be explained in terms of electric charge, current, voltage, and resistance. The corresponding electrical units are the coulomb for measuring charge, the ampere for current, voltage for potential difference, and the ohm for resistance. A basic element of electricity is the electric circuit. A circuit is a closed path that allows for the movement of charges. Current is the name given to the movement of charges. The study of electricity involves the behavior of charges, current, and voltage with the components that make up the circuit.

Digital electronics

2009-03-19T22:47:00.004+07:00

We see the digits 0 to 9 on an electronic calculator or digital watch, but digital electronics has a much broader meaning. The circuits for digital applications operate with pulses of voltage or current, as shown in figure (a). A pulse waveform is either completely ON or OFF because of the sudden changes in amplitude. In between values have no function. Note that the ON and OFF states can also be labeled HIGH or LOW, or 1 and 0 in binary notation, which uses only two digits. Effectively, the digital pulses correspond to the action of switching circuits that are either ON or OFF.

Actually, all the possible variations in types of electronic circuits can be divided into just two types-digital circuits that recognize pulses when they are HIGH or LOW, and analog circuits that use all values in the waveform. The applications of digital electronics, including calculators, computers, processing, and data communications, possibly the biggest branch of electronics. Many other applications, including radio and television, use both analog and digital circuits. Analog-to-digital (A/D) converters in change the signal from one form to the other.

Electric power

2009-03-19T22:40:00.000+07:00

These applications are in the generation and distribution of 60-Hz ac power, as the source of energy for electrical equipment. Included are lighting, heating, motors, and generators.

Communications electronics

2009-03-19T22:36:00.000+07:00

This field includes AM radio, FM radio with stereo, and television with color. The equipment is divided between transmitters and receivers. Also, transmitters can be divided between radio-frequency equipment to produce the carrier wave radiated from the antenna and the audio and video equipment in the studio that supplies the modulating signal with the desired information. high-fidelity audio equipment can be considered with radio receivers. The receiver itself has audio amplifiers to drive the loudspeakers that reproduce the sound. Satellite communications is also a transmit-receive system using electromagnetic radio waves. The satellite just happens to be orbiting around the earth at a height of above 22,000 miles in order to have a tremendous field of view. Actually, the satellite is a relay station for transmitter and receiver earth stations.

Application of Electronics

2009-03-19T22:31:00.005+07:00

In addition to its use in radio and television, electronics is used in almost all industries for control functions, automation, and computing. There are so many applications that the broad field of electronics must be considered in smaller areas. Three logical groupings of electronics applications are defined here. Also included is a brief description of some important divisions with some typical job titles for working in the electronics business.

Communications electronics
Electric power
Digital electronics

In addition to all the general applications in communications, digital equipment, and electric power services, several fields that could be of specific interest include automotive electronics, industrial electronics, and medical electronics. Both digital and analog techniques are used.

In automotive electronics, more and more electronic equipment is used in cars for charging the battery, power-assist functions, measuring gages, and monitoring and control of engine performance. Perhaps the most important application is electronic ignition. This method provides better timing of the ignition spark, especially at high speeds.

Industrial electronics includes control of welding and heating processes; the use of elevator control; operation of copying machines; metal detectors and smoke detectors; moisture control; and computer-controlled machinery. In addition, there are many types of remote-control functions, such as automatic garage door openers and burglar alarms. Closed-circuit television is often used for surveillance.

Medical electronics combines electronics with biology. Medical research, diagnosis, and treatment all use electronic equipment. Examples are the electron microscope and the electrocardiograph machine. In hospitals, oscilloscopes are commonly used as the display to monitor the heartbeat of patients in intensive care.

Citizen's Band (CB) Radio

2009-03-19T22:25:00.000+07:00

Forty 10-kHz channels from 26.965 to 27.405 MHz are available for public use of two-way radio. These CB channels are for class D service, with maximum power output of 4 watts (W). The CB transceiver includes a transmitter and a receiver. No operator's license is required for these personal radio services, often used in cars and boats.

Amateur Radio

2009-02-23T16:40:00.002+07:00

This field is one of the largest noncommercial radio services. Amateur radio operators, or "hams', usually build and operate their own transmitters and receivers to call one another in one of the assigned bands. A popular band is 7 to 7.3 MHz. Their main organization is the American Radio Relay League (ARRL), Newington, Connecticut.

Television Broadcasting

2009-02-23T16:38:00.003+07:00

Television is just another application of wireless radio communications, but with picture information in addition to the sound signal. Two separate carrier waves are transmitted by the station in its assigned channel. One carrier is an AM picture signal, modulated by video signal with the picture information. The other carrier is an FM sound signal modulated by the audio.

A television channel is 6 MHz wide to include both the picture and sound signals for each broadcast station. Channel 2, for instance is 54 to 60 MHz.

FM Radio Broadcast Band

2009-02-23T16:37:00.000+07:00

This band is 88 to 108 MHz, with the stations assigned every 200 kHz or 0.2 MHz. The system of frequency modulation reduces static and interference. For this reason, the FM band is used for broadcasting high-fidelity audio signals.

Standard AM Radio Broadcast Band

2009-02-23T16:35:00.000+07:00

This service is the original system of broadcasting for what we generally call radio. Amplitude modulation in transmission of the assigned RF carrier wave. Stations are assigned every 10 kHz in the band of 540 to 1600 kHz. The last digit is usually omitted from this numbers on the tuning dial for the carrier frequencies of different stations.

Radio Broadcast Service

2009-02-23T16:34:00.002+07:00

Radio is an abbreviated form of radiotelegraph and radiotelephone. The word radio means radiation for wireless transmission. At first, communication was by radiotelegraph, using short dots and longer dashes in the Morse code. Now radiotelephone is used more for voice and music programs for entertainment. This application can be considered as communications electronics, which includes television. Practically all radio and television receivers are now solid-state, with transistors and integrated circuits instead of vacuum-tube amplifiers. See figure for a comparison of the old and the new in radio.

The transmission distance for wireless communication can be less than a mile or as much as 5000 miles, depending on the type of service, there are many different uses, such as radio broadcasting of voice and music, television broadcasting, amateur radio, and citizen's band (CB) radio. In addition, radio communication is used for specific services, such as police radio. Finally, radio navigation for ships and planes is another important application.

All radio services in the United States are regulated by the Federal Communication Commission (FCC). The FCC assigns the RF carrier frequencies for transmission and monitors use of the airwaves.

Wireless Broadcasting

2009-02-23T16:30:00.004+07:00

Broadcasting means to send out in all directions. A radio broadcasting system is illustrated in Figure. The transmitter sends out electromagnetic radio waves radiated from its antenna. Receivers can pick up transmitted radio signal by means of receiving antenna or aerial. The receiver reproduces the desired signal transmitted by the broadcast station. There are many radio signals in space from different transmitters, but the receiver can be tuned to the frequency of the station we want.

In Figure, the electromagnetic wave shown is a radio-frequency (RF) carrier signal with amplitude modulation (AM). The Amplitude or strength of the RF carrier varies in step with variations in desired voice of music information, which is the audio signal. This technique of modulating a carrier wave is necessary because the audio signal itself cannot be used for wireless transmission. The variations are too slow for effective radiation from an antenna. A higher-frequency carrier wave is chosen for the best radio transmission. Its modulation provides the desired signal information.

In the method of frequency modulation (FM), the modulating signal varies the frequency of the RF carrier wave. Either AM or FM can be used for any type of modulating signal.

Frequency is an important characteristic of any varying voltage or current, to specify how fast the amplitudes change. A complete set of changes in one cycle. The number of cycles repeated in a second is the frequency. The unit for frequency is the hertz (Hz), equal to one cycle per second (cps). As an example, the 60 cycle ac power line has a frequency of 60 Hz.

Radio frequencies are generally considered to be about 30,000 Hz and above. Radio-frequency carrier frequencies for wireless transmission are usually specified in kilohertz (kHz), equal to 1000 Hz, and megahertz (MHz), where 1 MHz = 1,000,000 Hz.

Development of Electronics - II

2009-02-23T16:26:00.002+07:00

The rapid advances after that are due largely to the introduction and progress of the vacuum tube as an amplifier for electric signals. Dr. Lee DeForest, with his audion tube, invented in 1906, was a leader in this field. As the design of vacuum tubes advanced, radio broadcasting progressed rapidly. Regularly scheduled programs were broadcast in 1920 by station KDKA in the standard amplitude modulation (AM) radio band. The commercial frequency modulation (FM) radio broadcast service was started in 1939. Stereo broadcasting in this band began in 1961.

Commercial television broadcasting was started officially in 1941, but its popular use did not begin until 1945. Our present color television system was adopted in 1953.

Since the invention of transistors in 1948 at Bell Telephone Laboratories, solid-state devices have replaced tubes for most uses in electronics, radio, and television. The transistor is an application of controlled electron flow in solid semiconductor materials such as silicon (Si) and Germanium (Ge). Transistors and tubes have similar uses for the control of electron flow and amplification of signals. The transistor is much smaller, however, and more efficient, as it does not have the heater used in tubes.

Solid-state electronic devices include transistors, diodes, and integrated circuits. A diode is not amplifier but is used as a one-way conductor to convert alternating current to direct current. Solid-state devices have made new application practicable because of their small size and the economy of ICs packages. One example is the rapid growth of digital electronics for electronic calculators, personal computers, and many other uses.

Development of Electronics - I

2009-02-04T16:52:00.006+07:00

History shows that electronics started in the pioneer days of radio communications. Television developed from radio. Furthermore, radio itself is based on earlier experiments in electricity and magnetism. The start of wireless transmission for radio communications can be taken from the work of Heinrich Hertz, a German physicist. In 1887, he was the first demonstrate the effect of electromagnetic radiation through space. The distance of transmission was only a few feet. However, the experiment demonstrated that radio waves could travel from one place to another without the need for any connecting wires between the transmitting and receiving equipment.

Hertz proved that radio waves, although invisible, travel with the same velocity as light waves. In fact, radio waves and light waves are two examples of electromagnetic radiation. This form of energy combines the effects of electricity ad magnetism. An electromagnetic wave transmits electric energy through space.

The work of Hertz followed earlier experiments on electricity and magnetism. In 1820,a Danish physicist, H. C. Oersted, showed that an electric current produces magnetic effects. Then, in 1831, a British physicist, Michael Faraday, discovered that a magnet in motion can generate electricity. The motion provides the requirement of a change in the magnetic field. In 1864, the British physicist James Clark Maxwell, on the basis of earlier work in electricity and magnetism, predicted the electromagnetic waves demonstrated later by Hertz.

The importance of this work can be judge by the fact that basic units are named after this scientists. The Maxwell (Mx) and the Oersted (Oe) are units of magnetism. The Hertz (Hz) unit is equal to one cycle per second, which is the measure for the frequency of any alternating voltage or current. The Farad (F) is the unit of capacitance, indicating how much electric charge can be stored in a capacitor.

In 1895, Guglielmo Marconi used a long wire as an antenna to develop a practical radio system for long distance. The antenna is needed for efficient radiation. He succeeded in producing wireless communication across Atlantic Ocean in 1901.

Tips Cegah Virus

2009-02-04T16:27:00.004+07:00

Ada banyak cara untuk mencegah virus masuk ke komputer kita, mulai dari yang mudah sampai yang susah.. Cara yang paling gampang, adalah dengan memasang anti virus, tapi sayangnya cara ini tidak begitu menjamin komputer kita terbebas dari virus kelas teri apa lagi yang kelas kakap. Masalahnya satu, yaitu anti virus kita harus selalu up to date (update) database-nya, supaya bisa mengenali virus baru dan tidak semua orang tahu cara mengupdate anti virusnya atau mungkin malas untuk mencari update-annya, bahkan ada yang tidak memasang antivirus pada komputernya.

Nah, selagi mencari update terbaru anti virus anda, saya akan memberikan cara sederhana yang mudah-mudahan membuat komputer anda aman dari virus (tapi ga ngejamin 100%)..

Tekan tombol "SHIFT" berbarengan saat memasukkan flasdisk atau Disk ke CD ROM. Virus-virus sekarang banyak yang memanfaatkan fitur autorun yang disediakan oleh windows, inilah salah satu cara mencegah autorun tersebut dan otomatis sang virus pun tidak dapat berjalan untuk sementara waktu (sebelum di double klik virus induknya oleh user).
Buatlah folder dengan salah satu huruf diantaranya menggunakan simbol(yang berbentuk seperti huruf abjad) yang ada pada ms. word. Caranya, buka Ms. Word anda, kemudian insert simbol yang diinginkan (lebih baik yang seperti abjad), copy simbolnya, lalu rename folder yang anda inginkan atau baru anda buat, paste simbol tersebut. Untuk mengecek berhasil atau tidak hasil pekerjaan anda, copy-paste file .EXE ke folder yang tadi, lalu klik 2x(open),,jika filenya tidak terbuka atau ada peringatan dari Windowsnya, maka anda telah berhasil. Tujuan membuat folder ini adalah agar virus yang berakhiran .EXE tidak bisa aktif di dalam folder tersebut.

Baru dua hal diatas yang pernah saya coba untuk mencegah virus, walaupun tidak 100% persen aman dari virus, setidaknya ada usaha untuk mencegah virus masuk. Try it out...!!

Survey of Electronics

2009-01-15T09:58:00.004+07:00

Electronics, radio, and television are practical applications of general principles of electricity. The same electric current produced by battery for a flaslight can also be used in man different ways. Some examples are running a mtor producing heat and light for electric power applications, while electronic calculators and computers illustrate more advanced applications in digital electronics. In addition, radio and television are considered as communications electronics. They all are basedon the fundametal laws of electricity and magnetism. Magnetic effects are always associated with an electric current.

The name electronics comes from the electron, which is very small, invisible quantity of electricity present in all materials. In terms of its many uses, electronics can be defined to include all aplications involving the control of electricity in a vacuum, such as vacuum tubes, in gas or vapor, and in the solid semiconductor materials used for transistor and integrated circuits. The main in their operation is control of individual electrons for desired effect.In a transistor, as an example, tthe input can control a larger output current, to provide amplification. The Integrated-Circuit (IC) contains many transistor on a small semiconductor chip.

Resistor

2009-01-13T15:06:00.002+07:00

Basically, all the materials have resistif but some materials such as copper, silver, gold and metal materials in general have a very small resistansi. The material is to dispatch electric current well, so named conductor. Reverse of conductive material, such as the material of rubber, glass, carbon resistansi have a greater flow of electrons and is called as the insulator. How conduction principle, described in the article about the semiconductor.

Resistor is the basic electronic components used to limit the amount of cash that flows in a series. In accordance with his name and resistif resistor are generally made of carbon materials. Ohms of the law known, resistansi inverted proportionate to the number of current that flows through. Resistansi of a unit called Ohm resistor or symbol is represented with W (Omega).

Resistor type that is common tubular copper with two feet on the left and right. In the body there is a circle shape bracelet color code to make it easier to identify the large size of the measure without resistansi with Ohmmeter. Color code is the standard issued by the manufacturer EIA (Electronic Industries Association) as shown in the table below. Time author entry registration study electrical engineering, there was a test that must be fulfilled that is required is not color-blind.

Components of Electronic

2009-01-13T11:36:00.002+07:00

There are two kinds of Component in electronic:

Passive components are those that do not have gain or directionality. In the Electrical industry they are called Electrical elements or electrical components. They are such as : Terminal & Connectors, Switch, Resistors, Capasitors, Inductors, etc).
Active components are those that have gain or directionality, in contrast to passive components, which have neither. They include Semiconductors (Solid State Devices, Diodes, Transistors, Integrated Circuit - IC, Hybrid Circuit) and Thermionic Valves (Vacuum Tubes).

Electronic Component

2009-01-13T11:28:00.001+07:00

An electronic component is a basic electronic element usually packaged in a discrete form with two or more connecting leads or metallic pads. Components are intended to be connected together, usually by soldering to a printed circuit board>, to create an electronic circuit with a particular function (for example an amplifier, radio receiver, or oscillator). Components may be packaged singly (resistor, capacitor, transistor, diode etc.) or in more or less complex groups as integrated circuits (operational amplifier, resistor array, logic gate etc.)
(wikipedia.org)

Definition of Electronics

2009-01-13T10:57:00.001+07:00

Electronics is the study of the flow of charge through various materials and devices such as semiconductors, resistors, capasitors, inductors, nano-structures.

Although considered to be a theoretical branch of physics, the design and construction of electronic circuits to solve practical problems is an essential technique in the fields of electronic engineering and computer engineering. This science started around 1908 with the invention by Lee De Forest of the valve (triode). Before 1950 this science was called “Radio technics” because its principal application was the design and theory of radio transmitters and recievers.

The study of new semiconductor devices and surrounding technology is sometimes considered a branch of physics. This article focuses on engineering aspects of electronics.
(electro08.wordpress.com)

Analog Signal

2009-01-12T15:53:00.005+07:00

An analog signal uses some attribute of the medium to convey the signal's information. For example, an aneroid barometer uses angular position as the signal to convey pressure information. Electrical signals may represent information by changing their voltage, current, frequency, or total charge. Information is converted from some other physical form ( such as sound, light, temperature, pressure, position) to an electrical signal by a transducer.

The signals take any value from a given range, and each unique signal value represents different information. Any change in the signal is meaningful, and each level of the signal represents a different level of the phenomenon that it represents. For example, suppose the signal is being used to represent temperature, with one volt representing one degree Celsius. In such a system 10 volts would represent 10 degrees, and 10.1 volts would represent 10.1 degrees.

Another method of conveying an analog signal is to use modulation. In this, some base carrier signal has one of its properties altered: amplitude modulation (AM) involves altering the amplitude of a sinusoidal voltage waveform by the source information, frequency modulation (FM) changes the frequency. Other techniques, such as changing the phase of the carrier signal are also used.<

In an analog sound recording, the variation in pressure of a sound striking a microphone creates a corresponding variation in the current passing through it or voltage across it. An increase in the volume of the sound causes the fluctuation of the current or voltage to increase proportionally while keeping the same waveform or shape.

Mechanical, pneumatic, hydraulic and other systems may also use analog signals. (wikipedia.org)

Analog Electronics

2009-01-12T15:38:00.003+07:00

What is Analog Electronics??
Analog electronics (or analogue in British English) are those electronic systems with a continuously variable signal.The term "analogue" describes the proportional relationship between a signal and a voltage or current that represented the signal. (en.wikipedia.org)

Historically, analog electronics was used in large part because of the ease with which circuits could be implemented with analog devices. However, as signals have become more complex, and the ability to fabricate extremely complex digital circuits has increased, the disadvantages of analog electronics have increased in importance, while the importance of simplicity has declined.

In analog electronics, the signals to be manipulated take the form of continuous currents or voltages. The information in the signal is carried by the value of the current or voltage at a particular time t. Some examples of analog electronic signals are amplitude-modulated (AM) and frequency-modulated (FM) radio broadcast signals, thermocouple temperature data signals, and standard audio cassette recording signals. In each of these cases, analog electronic devices and circuits can be used to render the signals intelligible.

Commonly required manipulations include amplification, rectification, and conversion to a nonelectronic signal. Amplification is required when the strength of a signal of interest is not sufficient to perform the task that the signal is required to do. However, the amplification process suffers from the two primary disadvantages of analog electronics: (1) susceptibility to replication errors due to nonlinearities in the amplification process and (2) susceptibility to signal degradation due to the addition, during the amplification process, of noise originating from the analog devices composing the amplifier. These two disadvantages compete with the primary advantage of analog electronics, the ease of implementing any desired electronic signal manipulation.

Rule of Page

2009-01-12T14:53:00.003+07:00

This Blog was made to increase and to share all about electronics or electric engineering. Elctronics in life.
Technology involving the manipulation of voltages and electric currents through the use of various devices for the purpose of performing some useful action. This large field is generally divided into two primary areas, analog electronics and digital electronics.