digital circuit

digital circuit, electronic circuit that can take on only a finite number of states. That is contrasted with analog circuits, whose voltages or other quantities vary in a continuous manner. Binary (two-state) digital circuits are the most common. The two possible states of a binary circuit are represented by the binary digits, or bits, 0 and 1. The states are also commonly referred to as "on" and "off" or "high" and "low" (see information theory). The simplest forms of digital circuits are built from logic gates, the building blocks of the digital computer. Since most of the physical variables encountered in the real world, e.g., position and temperature, exist in analog form, they are represented electrically by continuously varying currents and voltages in analog circuits. To make digital and analog circuits compatible special converters are used-either analog-to-digital or digital-to-analog depending on the direction of information flow. Digital circuits simulate continuous functions with strings of bits; the more bits that are used, the more accurately the continuous signal can be represented. For example, if 16 bits are used to represent a varying voltage, the signal can be assigned one of more than 65,000 different values. Digital circuits are more immune to noise than analog circuits, and digital signals can be stored and duplicated without degradation (see compact disc). Digital circuits can often manipulate signals more effectively-and less expensively-than analog circuits. Those reasons helped digital systems to succeed over all analog contenders for proposed high-definition television in the United States.

Information can be represented and stored on a variety of electrical/mechanical devices. In many cases, the information relates to measurable variables such as elapsed time or total rainfall or accumulated electrical charge (for which the hourglass, raingauge, and capacitor, respectively, are suitable representation devices). But what about abstract information, such as quantities in mathematics? Here we create an analogy between something that can be stored and measured in an electrical/mechanical device and a mathematical value. For example, we can assign an equivalence between mathematical value and electrical charge. The extent to which we can operate on that electrical charge via the capacitor and our measuring instruments is the degreee to which we can perform analogous mathematical calculations.

There are problems, however, with relating mathematics to storable parameters on physical devices. Two of the more important ones are 1) measuring instruments are rarely more accurate than three decimal digits--so mathematics carried out through these devices would have intrinsic limited accuracy; 2) there is typically unrecoverable loss of information--a capacitor could leak away part of its charge, i.e., its analogous mathematical value would arbitrarily change.

But there is a solution to these problems: store mathematical values in discrete rather than analog form. Here one uses devices whose variations are limited to discrete states--typically two, e.g., on or off, positive or negative, closed or open. Then, by representing mathematical quantities in a number system having only two digits--a binary number system--any value can be represented with arbitrary accuracy by linking together a sequence of two-state devices and setting the appropriate state for each device. Information integrity in this discrete representation is better than that of analog representation because here information loss requires an arbitrary change of state of a device, not a drift in value. That is much less likely, and there are ways to correct for it.

Computers

Computers are developed to store and mathematically manipulate quantitative information. Earlier computers were analog--usually electrical or mechanical. Circuits and mechanisms were built to represent fixed mathematical problems with results appearing in the form of a final voltage or a rotation angle of a gear. The electrical and mechanical equivalents of addition, multiplication, integration, and differentiation were incorporated into these computers. Complex problems could be solved, albeit with the accuracy problems mentioned above.

Then the digital computer emerged. Here the electrical and mechanical analogies for mathematical operations are replaced by the digital manipulation of 1's and 0's--the two possible states of binary devices storing information. How does one carry out mathematics with binary devices? That is the topic of this exercise.

Binary Logic

The objective is to devise and to piece together a series of binary logic elements to effect an ultimate mathematical operation such as addition, or subtraction, or multiplication. It is necessary and sufficient to consider logic elements for which there are two binary inputs and one binary output. We consider three logic elements from which all binary logic may be constructed: the AND, OR, and NOT gates.

Problems

Note: in the problems that follow, use the circuit builder to develop your circuits. When you link to the circuit builder you will be asked to specify the number of inputs and outputs--that will be determined, of course, by the problem. You will then be presented with the circuit display having the specified number of inputs and outputs. To build your circuit, drag logic components into the circuit area. Inputs (circles) may be connected to outputs (squares) by clicking first on one, then dragging to the other and releasing the mouse button. (A single output (square) may be connected to several inputs (circles), but only one output may be connected to any input.) Once your circuit is completed you can choose either single input or all inputs. With the single input option, you can specify a particular bit configuration of inputs. Once these inputs are specified, the state (1 or 0) of each logic line will be displayed. This will give you an opportunity to find errors in your circuit. With the "all possible inputs" option, outputs for all possible inputs will be presented. This should be your final confirmation that your circuit operates correctly.

Click here to view the available logic elements, their graphic representation, and their input/output tables.

1. Confirm that each of the elementary circuits behaves as advertised. That is, use the circuit builder to establish the logic behavior of AND, NOT, OR, NAND, NOR. These will all be two-input and one output circuits (except for NOT, which will be one input and one output).

2. Using only the component NAND, create a circuit that is equivalent to the logic of an AND gate. Do the same to emulate a NOT gate. Do the same to emulate an OR gate. (If this is doable, it means that all binary logic circuitry can ultimately be generated from the single logic element NAND).

3. Using only the component NOR, see if you can create circuits equivalent to AND, OR, and NOT is you did in problem 2.

4. Using only AND, NOT, and OR produce a three-input AND circuit, i.e., the output is 0 unless all three inputs are a 1. (You don't have to use all three circuit elements.)

5. Using only AND, NOT, and OR produce a three-input OR circuit, ie., the output is 1 if any of the inputs is 1.

6. Create a two-input "adder" with two outputs: the one-digit result of the add, and the value of a "carry" bit. In binary arithmetic, 1+1=0 with a carry=1.

7. One of the more interesting public works problems is the "Superbowl" problem. At the beginning of halftime during the Superbowl, 35 million toilets are flushed almost simultaneously. The resulting loss of water pressure wreaks havoc on many municipal water systems. Here you will solve the problem for a "three toilet" system. Devise a logic circuit whose "1" inputs represent "flushes" and whose "1" outputs represent opened water-feed valves. If no more than one toilet is flushed, then that toilet's water valve opens, the others remaining closed. If more than one toilet is flushed, then all the water valves remain closed.


8. You are designing a robot to move toward a light source. Three photosensors SL, SC, and SR are mounted at the front of the robot pointing 45o to the left, straight ahead, and 45o to the right, respectively. Two wheels WL and WR are powered depending on the output of the sensors. If SL detects light, the robot is pointing too far to the right, and the right wheel WR must be powered up to turn the robot to the left. The opposite is necessary if SR receives light. If only the forward-pointing sensor SC is lit, then both wheels WL and WR should be powered to propel the robot forward. If one treats the sensors as having binary outputs, i.e., either "on" or "off", and the powered wheels as being "on" or "off", a simple logic circuit can be used to actuate the wheels under each sensor condition. Create such a logic circuit using only NAND gates, and using the least number of these.

9. This picture is a schematic diagram of a 14-pin CMOS chip that contains 4 NAND gates. Your task is to design a printed circuit board that implements the robot circuit you produced in problem 8. Using as many CMOS chips as necessary, and taking into consideration which pins constitute inputs and outputs, create the circuit by connecting the appropriate pins. But now, try to route the connections so that the "wires" don't cross one another. This is a typical problem in printed circuit design. The objective is to "etch" the circuit onto a single layer of a copper-coated circuit board which contains pin holes to accommodate the chips. (Note: this problem does not require the use of the CIRCUIT BUILDER. Just sketch out the connections between the chip(s).

READ MORE - digital circuit

AND OR

In this animated AND Logic example of Doors Opening and Closing, you can see that in order for the "Light" to get through the house, the front door AND the back door must be Open.

Same example: if either the front door OR the back door is Closed the light does NOT get through.
In this animated OR Logic example, you can see that in order to get light through the house: the left front door OR the right front door (or both) must be Open.
Same example: in order to block the light through the house: the left front door AND the right front door must be Closed.

In order for the Output of an AND Logical Function to be TRUE: input (1) AND input (2) must both be TRUE. This is Positive Logic. Hint: TRUE is when the switch is closed, applying power to the LED. FALSE is when the switch is open, NOT applying power to the LED)



Using the Same Function --It is also correct to say: If either input (1) OR input (2) (or both) is NOT TRUE the Output Will be FALSE. This is Negative Logic.
In order for the Output of an OR Logical Function to be TRUE: either
input (1) OR input (2) (or both) must be TRUE. This is Positive Logic.



Using the Same Function --It is also correct to say: In order for the Output to be FALSE: input (1) AND input (2) must both be FALSE. This is Negative Logic.

Remember:
1) A Positive AND gate is a Negative OR gate
2) A Positive OR gate is a Negative AND gate
Logic Element Symbols

READ MORE - AND OR

Digital electronics

Digital electronics represent signals by discrete bands of analog levels, rather than by a continuous range. All levels within a band represent the same signal state. Relatively small changes to the analog signal levels due to manufacturing tolerance, signal attenuation or parasitic noise do not leave the discrete envelope, and as a result are ignored by signal state sensing circuitry.

In most cases the number of these states is two, and they are represented by two voltage bands: one near zero volts and a higher level near the supply voltage, corresponding to the "false" ("0") and "true" ("1") values of the boolean domain respectively.

One advantage of digital circuits when compared to analog circuits is that signals represented digitally can be transmitted without degradation due to noise. For example, a continuous audio signal, transmitted as a sequence of 1s and 0s, can be reconstructed without error provided the noise picked up in transmission is not enough to prevent identification of the 1s and 0s. An hour of music can be stored on a compact disc as about 6 billion binary digits.

In a digital system, a more precise representation of a signal can be obtained by using more binary digits to represent it. While this requires more digital circuits to process the signals, each digit is handled by the same kind of hardware. In an analog system, additional resolution requires fundamental improvements in the linearity and noise characteristics of each step of the signal chain.

Computer-controlled digital systems can be controlled by software, allowing new functions to be added without changing hardware. Often this can be done outside of the factory by updating the product's software. So, the product's design errors can be corrected after the product is in a customer's hands.

Information storage can be easier in digital systems than in analog ones. The noise-immunity of digital systems permits data to be stored and retrieved without degradation. In an analog system, noise from aging and wear degrade the information stored. In a digital system, as long as the total noise is below a certain level, the information can be recovered perfectly.

READ MORE - Digital electronics

Digital or binary logic

Digital or binary logic has fascinated many people over the years. The very idea that a two-valued number system can possibly be the basis for the most powerful and sophisticated computers seems astounding, to say the least. Nevertheless, it is so, and the how and the why of this requires some explanation.

Everything in the digital world is based on the binary number system. Numerically, this involves only two symbols: 0 and 1. Logically, we can use these symbols or we can equate them with others according to the needs of the moment. Thus, when dealing with digital logic, we can specify that:

0 = false = no
1 = true = yes

Using this two-valued logic system, every statement or condition must be either "true" or "false;" it cannot be partly true and partly false. While this approach may seem limited, it actually works quite nicely, and can be expanded to express very complex relationships and interactions among any number of individual conditions.

One essential reason for basing logical operations on the binary number system is that it is easy to design simple, stable electronic circuits that can switch back and forth between two clearly-defined states, with no ambiguity attached. It is also readily possible to design and build circuits that will remain indefinitely in one state unless and until they are deliberately switched to the other state. This makes it possible to construct a machine (the computer) which can remember sequences of events and adjust its behavior accordingly.

READ MORE - Digital or binary logic

Capacitor bank is an equipment used to improve power factor

Capacitor bank is an equipment used to improve power factor, eliminate the interference voltage and reactive power control. But the use of capacitor banks in the world of electricity, which means the operation known as capacitor bank switching can cause new problems in an effort to improve the quality of power, namely the onset of symptoms of high voltage transient (transient overvoltages). In this final project, conducted testing and analysis of transient overvoltages simulation using MATLAB SIMULINK software based data transmission, such as voltage and impedance channels obtained from Waru substation. The test results of simulation with MATLAB SIMULINK shows that the transient overvoltages generated by the operation of the capacitor bank switching on the transmission system substation Waru to achieve the highest value of 1.74 pu at 150 kV transmission system and 2.2 pu at 70 kV transmission system. From the analysis found that the transient overvoltages generated will increase if the voltage level positions closer to the load. This is certainly dangerous because it can damage electrical equipment.

Many say let the electricity bill cheap disposable capacitor bank, but the opinion was not completely wrong or completely right nor because the main function is to maximize tire capacitor power that we have or eliminate the reactive power that we use, because the reactive power charge is PLN (kvarh ) on us, so that with the decrease in reactive power kVA then we only pay a maximum of just making it more and cheaper electricity costs
some things that affect the age capacitor bank

There are two things that affect the capacitor bank

environmental temperature: the higher the labor room temperature the faster the capacitor bank during his lifetime

Harmonics generated: harmonic disturbances that often make life in capacitor banks become increasingly narrow

some equipment that can cause the capacitor bank is rapidly broken
Inverter, DC Drive
UPS or power supply uninteruptable
soft starter
welding machine
rectifier
fluorescent light
arc furnace
laser

by knowing this can we be expected to maximize the use of capacitor banks.

Some problems in the capacitor bank
this incident one of my customers when the capacitor bank exploded, many of us as actors maintenance or engineering are often asked, why capacitor banks explode ..? actually a lot of factors why the capacitor banks could explode following some discussion about the cause - the cause of capacitor banks can explode:

From my observations (CMIIW), many cases of fires at the plant caused by exploding / burning of the capacitor bank.

- I wonder what factors which trigger the explosion / burning of the capacitor bank?

- What are the reply must be considered in the design, installation and maintenance capacitor bank?

- From all electrical maintenance there any specific standards for maintenance?

May exist between rekan2 this mailing list who wish to comment about things they will be on top. Incidentally my background is not electrical. So I do not quite understand how to work and who are in operational hazard capacitor banks.

As short as I know there are several causes of capacitor banks quickly broken:

1. Voltage capacitors, since capacitors are very sensitive to voltage.

2. Room temperature.

3. Working frequency capacitors, whether pairs of capacitors which comply with the frequency mas we can to 50Hz or 50/60Hz (if not sure ask the vendor staement dr letter capacitors).

4. Quality power of the existing system in place mas darma, I often encountered cases are often damaged due to system capacitors containing high harmonics, so that when the capacitor has resonance with the system will occur surge that will damage the capacitor. So also the case I have ever met, the system prior to install capacitor banks no harmonics are significant, but once installed capacitor banks actually harmonics that appear in the system significantly. These harmonics appear due to the non linear load2 such as rectifiers, UPS, battery charge etc..

My suggestion to design a good capacitor bank is enabled as well as harmonic filters, to determine the initial harmonics in the system was measured first by measuring alat2 who have a lot of maintenance store.The capacitor bank room temperature maintained enough is enough.

Please corrected if I am wrong.

Generally, the load on the electricity grid is an inductive load. Some existing inductive loads in electricity network, such as the heater, Neon, electric motor, etc. So the electrical load is mostly inductive load. To eliminate / reduce this inductive power component that is required compensator capacitor / capacitor bank. PLN KVARH charge excess usage on the customer, if the average power factor (cos phi) is less than 0.85. To improve power factor so as not paying fines, should use the Application panel capacitor bank.
The main functions of capacitor bank
capacitor banks eliminate penalty / excess cost (kVARh)
Avoid overloaded transformers
Provide additional resources available
Avoiding the increase of current / temperature on the cable
capacitor bank serves to maximize the power consumption (kVA)
Power saving / efficiency
Avoiding Line Voltage Drop
preserve installation & Electrical Appliances
Capacitor banks are also reducing the losses - other loss on electrical installations

with the increasingly high cost of electricity in Indonesia, the electricity users must be clever - clever maximize its power and make savings so that electricity costs are not to be expensive.

Judging from how it works, capacitor banks are divided into 2:

Fixed capacitor bank type, with a fixed capasitive burden despite load changes. Usually used to direct cost as in the induction motor. A safe value is 5% of motor capacity, consideration is no-load current conditions.

Automatic type, giving capasitive burden that varies according to load conditions. Type panel is equipped with a Power Factor Controller (PFC),Cos phi PFC will maintain the network in accordance with the specified target. For fluctuating loads quickly used the Static Var Compensator type (SVC) using Thyristor as switcher. As for the load fluctuations are not too quick to use Dynamic Var Compensator using Magnetic Contractor and relay as a switcher PFC.

READ MORE - Capacitor bank is an equipment used to improve power factor

An audio equalizer

An audio equalizer, also known as a graphic equalizer, is a set of sliders that allows the stereo user to increase or reduce bands of sound that are on frequencies. The result is a more focused sound, with bass and treble specifications to suit the individual listener. The name from graphic equalizer comes from the fact that we can see the audio levels as we are adjusting them. A typical audio equalizer includes a series of filters and amplifiers that are each set to a certain frequency. A typical audio equalizer will have two sets of these levels, one for each channel in the stereo system. Gain controls affect volume, and are typically represented by a button that you slide up or down. Audio equalizers are most frequent in medium- to high-grade stereo systems, and every recording studio worth its salt will have one. You can even find equalizers for your computer sound, or for your car stereo.

Different kinds of media sound differently on various graphic equalizers. For example, a particular device may play music files better than audio on feature films. In addition, be sure to find an audio equalizer that that doesn’t fuzz up or distort the sound, which is a common problem among audio equalizers. Audio equalizers are great for people with an extensive music collection that includes older recordings, such as cassettes and older CDs. Graphic equalizers brighten up the sound.

Another thing to consider when purchasing a graphic equalizer are “sticky buttons,” or buttons or slides that do not move as easily or as intuitively as you would like them to. Sticky buttons can result in the cutting out of sound on certain frequencies, negatively affecting the quality of sound. In addition, once you find the perfect balance among dials and switches, some models do not contain hash marks that allow you to easily remember these things. This can be easily remedied by applying magic marker to the places that you would like to remember.

Below are some examples of top equalizers in the market.

The Samson D2500 Digital Graphic Equalizer has 31 bands of sound and includes a fader, programmable delay, a noise gate, low pass filters, a limiter and an enhancer. There are up to 1010 programmable settings available, and the device includes a three year warranty that includes parts and labor. Samson S Curve 215 Dual 15 Band Equalizer gives the user control over two audio channels. With a range of 12 dB, users can move sliders that are lit up using LED (light emitting diode) technology. Because the equalizer is low-noise, there are a variety of ways this device can be used, including during live performances and studio recordings. At 15 bands, each frequency represents 2/3 an octave with a range of 25 Hz to 16 kHz. Other features include a switchable low-cut filter at 80 Hz. This feature reduces extra noises and movement. In addition, XLR and TRS connectors are electronically balanced, there are options for stereo or the use of two monophonic signals. There is also faders, circuits that prevent thumps, an internal power supply and a useful 19″ rack design. This device also includes a three year warranty, including parts and labor. The Samson S Curve 231 Dual 31 Band Equalizer has a range of 24 dB, but is otherwise very similar to the Samson S Curve 215, except that it has 31 bands of frequency (rather than 15).

The dbx 1215 Dual 15 Band Equalizer offers 15 2/3 octave bands, dual channels, a range of 12 dB and ISO frequency centers. Other features include low-cut filters, gain adjustments, a barrier strip and easy to use connectors. The dbx 231 Dual 31 Band Graphic Equalizer also is a popular choice. Features of this device include two channels of 31 bands that at 2/3 of an octave. The range is from 6 to 12 dB (12sB per octave) and a low-cut filter is 40 Hz. A front panel switch, LED displays and an internal transformer are other features of this device. The four-band Summit Audio FEQ50 Tube and Solid State Equalizer is passive with a range of 14 dB. There are six frequencies per band, a master bypass and a separate bypassable high pass filter. This device comes with a 3-year warranty.

READ MORE - An audio equalizer

The characteristics of electromagnetic waves

Creeping wave is a vibration. Ideal shape of a wave will follow the motion sinusoide. Apart from electromagnetic radiation, and possibly gravitational radiation, which can run through a vacuum, there are also on medium wave (which is due to change in form can produce restoring forces which flexure) where they can walk and can transfer energy from one place to another without causing particle medium migrate permanently, ie no mass displacement. In fact, every special point oscillates around a certain position.

A medium is called:
linear if the waves are different in every particular point in the medium can be summed,
limited, if limited, but it is called infinite
uniform if its physical characteristics do not change at different points
isotropic if the physical characteristics of the "same" in different directions

Electromagnetic waves are waves that can propagate though no medium. Propagate in a wave of electromagnetic energy with a few characters that can be measured, namely: wavelength / wavelength, frequency, amplitude / amplitude, velocity. Amplitude is the height of the wave, while the wavelength is the distance between two peaks. Frequency is the number of waves passing through a point in one unit of time. Frequency depends on the speed of the wave vine. Because the electromagnetic energy is a constant speed (the speed of light), wavelength and frequency is inversely proportional. The longer a wave, the lower the frequency, and the shorter the wave the higher frequencies.

Electromagnetic energy emitted, or released, by all the time in the universe at a level different. Higher levels of energy in an energy source, the lower the wavelength of the energy produced, and the higher frequency. Different characteristics of the wave energy is used to classify electromagnetic energy.

The characteristics of electromagnetic waves:
From the description above can conclude several characteristics of electromagnetic waves is as follows:

1. Changes in the electric field and magnetic field occurs at the same time, so that the two fields have a maximum and minimum prices at the same time and at the same place.

2. The direction of electric field and magnetic field perpendicular to each other and both perpendicular to the direction of wave propagation.

3. From the characteristics of No. 2 showed that electromagnetic waves are transverse waves.

4. Like the waves in general, an incident electromagnetic wave reflection, refraction, interference, and diffraction. Also experienced a polarization event because it included a transverse wave.

5. Fast propagation of electromagnetic waves depends only on the electrical properties and the magnetic medium by which this occurred.

Light visible to the eye is not only the type that allows electromagnetic radiation. Opinions James Clerk Maxwell showed that electromagnetic waves other, in contrast to visible light by the eye in his wavelength and frequency, could have been there. These theoretical conclusions were remarkably reinforced by the Heinrich Hertz, who could produce and meet the two waves are visible by eye was predicted by Maxwell. A few years later Guglielmo Marconi demonstrates that the wave of the invisible eye that can be used for communication without wires, so what was his name is radio. Now, we use also for television, x-rays, gamma rays, infrared rays, ultraviolet rays are examples of electromagnetic radiation. Everything can be learned through the ideas of Maxwell.

SOURCE electromagnetic waves
Electrical oscillations.
sunlight produces infrared rays.
mercury lamp produces ultra violet.
The shooting of electrons in vacuum tubes on the metal pieces produce X-rays (used for x-rays).

Unstable nuclei produce gamma rays.

SPECTRUM electromagnetic waves
The composition of all forms of electromagnetic waves based on wavelengths and frequencies called the electromagnetic spectrum. Image of the electromagnetic spectrum below have been prepared on the wavelength (measured in units _m) includes a very low energy range, with wavelengths of high and low frequencies, like radio waves to very high energy, with a low wavelength and high frequency radiation such as X -ray and Gamma Ray.

Examples of the electromagnetic spectrum
Radio waves
Radio waves are classified according to wavelength or frequency. If the wavelength is high, then definitely a low frequency or vice versa. The frequency of radio waves from 30 kHz up and grouped according to broad bands. The radio waves generated by electric charges are accelerated through conductive wires. These charges are generated by electronic circuit called the oscillator. These radio waves emitted from the antenna and received by the antenna as well. You can not hear the radio directly, but the radio receiver will change the first wave energy into sound energy.

Microwaves
Microwaves (mikrowaves) is a radio wave with the highest frequency that is above 3 GHz. If the microwaves are absorbed by an object, it would appear that the warming effect on the body. If the food absorb microwave radiation, then the food becomes hot in a very short time interval. The process is utilized in a microwave oven to cook food quickly and economically.

Microwaves are also used in aircraft RADAR (Radio Detection and Ranging) RADAR means finding and determine the trace of an object using microwaves. Aircraft radar utilizing the reflection properties of microwaves. Because the velocity of electromagnetic wave c = 3 X 108 m / s, then by observing the time interval between transmitting the reception.


Infrared Rays
Infrared rays covering area up to 1014 Hz 1011Hz frequency or wavelength region 10-4 cm to 10-1 cm. if you check the spectrum produced by an incandescent lamp with a detector which is connected to the miliampermeter, then the needle ampermeter slightly above the tip of the red spectrum. Light rays are not visible but can be detected in the upper red spectrum is called infrared radiation.
Infrared rays produced by electrons in the molecules vibrate as Theys That in heat. So Would any hot objects emit infrared light. The amount of infrared light emitted Depends on temperature and color of objects.

Visible light
Visible light as electromagnetic radiation most familiar to us can be defined as part of the electromagnetic wave spectrum that can be detected by human eye. The wavelength depends on the color looks nervariasi wavelengths ranging from approximately 4 x 10-7 m to light violet (purple) to 7x 10-7 m for a red light. Usefulness of light one of them go round the use of lasers in optical fiber for telecommunications and medical.


Ultraviolet Rays
Ultraviolet light has a frequency of 1015 Hz in the region until 1016 Hz or in a long region wave 10-8 m 10-7 m. these waves are generated by atoms and molecules in electric flame. The sun is a major source that emits ultraviolet rays on the surface of the earth, the ozone layer is in the top layer that serves atmosfer absorb ultraviolet rays and ultraviolet rays forward that does not endanger the lives of living beings on earth.

X-ray
X-rays have a frequency between 10 Hz to 10 Hz. very short wavelength of 10 cm to 10 cm. although such an X-ray but has strong penetrating power, can penetrate thick books, wood several inches thick and 1 cm thick aluminum plate.

Gamma Rays
Gamma rays have a frequency between 10 Hz to 10 Hz or a wavelength of between 10 cm to 10 cm. Greatest penetrating power, which causes serious effects when absorbed by body tissue.

Examples of the application of electromagnetic waves in everyday life:

Radio

Radio energy is the lowest form of electromagnetic energy levels, with a range of wavelengths from thousands of kilometers to less than one meter. The use of most of the communication, to investigate outer space and radar systems. Radar is useful to study the weather patterns, storms, making the 3D map of the earth's surface, measure rainfall, movement of ice in the polar region and monitor the environment. Radar wavelength range between 0.8 - 100 cm.

Microwave

Microwave radiation wavelength range between 0.3 - 300 cm. Its use is mainly in the fields of communication and information delivery through open space, cooking, and PJ system active. In PJ active system, a microwave pulse is fired through a target and its reflection was measured to study the characteristics of the target. As an application example is the Tropical Rainfall Measuring Mission's (TRMM) Microwave Imager (TMI), which measures the microwave radiation emitted from the electromagnetic spectrum Electromagnetic energy of the earth's atmosphere to measure evaporation, water content in clouds and rain intensity.

Infrared

Health conditions can be diagnosed by investigating the infrared emission from the body. Special infrared photo called thermogram is used to detect blood circulation problems, arthritis and cancer. Infrared radiation can also be used in burglar alarms. A thief without his knowledge will impede the light and hide the alarm. Communicate with the TV remote control via infrared radiation generated by the LED (Light Emitting Diode) contained within the unit, so that we can turn on the TV from a distance with a remote control.

d. Ultraviolet
UV light is needed in the assimilation of plants and can kill the germs in the skin.

e. X-ray
X-rays are commonly used in the medical field to photograph the position of the bones in the body especially to determine a broken bone. However, the use of X-rays have to be careful because the network of human cells can be damaged by use of X-rays that are too long.

READ MORE - The characteristics of electromagnetic waves