The Internet

Area networks are subdivided depending on the distance devices such as computers, printers, speakers, etc. can communicate with each other. Those only capable of short distances are local area networks (LAN). Metropolitan area networks (MAN) encompass much larger ranges such as cities. Wide area networks (WAN) can connect computer devices globally and is referred to as the internet requiring substantial computing and transmission capabilities offered by internet service providers (ISPs).

To date there are only two ways to interconnect devices, either hard wired or by using radio waves. Hard wired goes way back to the old telegraph days evolving to the present day ethernet connecting several computer systems together to form a local area network. Ethernet is covered in IEEE 802.3. Twisted pair wires and coaxial cables have been made more efficient with the advent of CAT 5, CAT 6 and so on now capable of more than 10 gigabits per second.

An analog signal is basically a sine wave with information made possible by a variation in its amplitude or difference in its energy and variation in its frequency or difference in the time taken for the wave to complete its cycle. What we see and hear is an analog signal.  Just as telegraphs used dots and dashes interpreted by Morse Code computers have become much faster and more efficient using a series of pulses using 0s and 1s, either the presence of a voltage or not. 10 GBs is one thousand million 0s an 1s transferred each second. Fiber optical cable using tiny glass or plastic threads transmit light instead of voltage making these pulses even faster and capable of maintaining integrity over much larger distances. Fiber optic cable now lay at the bottom of oceans making communication between countries around the world possible.

Routers are not the same as modems. Routers interconnect several devices including the modem together to form a network. Every computer, printer, TV, speaker system, modem, etc. has a unique number. A router determines the address of the device data is to be sent to and ensures information is sent back to the address of the devise it is communicating with and to prohibit transmission at the same time by more than one device. This prevents the printer from communicating with the speaker system for example. Routers route traffic between the devices and modem communicating with the internet.

With the advances of satellites, we depend more on wireless communication. Our satellite TVs and cell phones are wireless using radio waves. As of now radio waves use analog technology by varying the amplitude and frequency of sine waves. Maybe not as efficient as ethernet but more convenient. That’s where modems come in, converting information on radio waves into digital pulses used by computers. Wide area networks, or the internet, use analog radio waves changed to digital signals by modems required by computers in a local area network (LAN). Modems do this by modulating and demodulating analog and digital signals back and forth depending on whether the operator is sending or receiving information.

Analog radio waves are usually classified as either VHF or UHF. The number of sine waves an analog signal has a second is measured in hertz. Very high frequencies (VHF) operate between 30 to 300 million hertz (MHz) mostly used for radios. Televisions, cell phones, etc. require much more information in a quick period of time and use ultra-high frequencies operating between 300 MHz and 3 gigahertz (GHz).

Wi-Fi exchanges data between digital devices by using UHF radio waves. It links computers, phones, televisions, speakers, printers and so forth in local area networks. A hot spot is where the distance between devices is close enough to allow the radio waves between them to be received efficiently.  Repeaters extend the range of wireless local area networks (WLAN). The Wi-Fi Alliance incorporates about a thousand companies globally and is addressed by the Institute of Electrical and Electronic Engineers in IEEE 802.11. Roaming occurs between overlapping hot spots.

Bluetooth is also wireless using ultra high frequencies much like Wi-Fi but is only effective for very short distances up to about 30 feet to create a personal area network (PAN). It is discussed in IEEE 802.15.1 and is controlled by the Blue Tooth Special Interest Group (SIG) which owns its trademark. For Bluetooth to work a special transceiver chip must be embedded in each device intended to communicate with each other.

Although used extensively to access the world wide web the internet is different. The internet interconnects computer networks around the world and can be used to exchange other data such as email, sharing files including videos, music, and messaging for instance. The internet has no dominant administration and is supported by the Internet Engineering Task Force (IETF).

One definition of protocols by Merriam-Webster is a code prescribing strict adherence to correct etiquette procedure. In the computer world protocols are a set of rules for arranging and processing data. Internet protocols include Internet Protocol Security (IPsec), Internet Control Messaging (ICMP), and Internet Group Management (IGMP). In addition there are protocols in transparent layers (TCP). HTTP is a Hyper Text Transfer Protocol. In the dictionary hyper is referred to as existing in a space of more than three dimensions. In the internet world this means a text does not need to be read from start to finish, but keywords can be accessed taking the reader to other pages or websites as far as that is concerned. These are called hyperlinks. HTTPS is basically HTTP that is encrypted. To encrypt is defined in the dictionary as a method of transforming a text into code to conceal its meaning. This prohibits hackers and malware unless they know the code. Updates may possibly be changing the encryption. HTTPS is somewhat similar to a third layer TLS/SSL: Transparent Layer Security or Secure Socket Layer. A fourth is UDP: User Diagram Protocol which is TCP with a fast response. HTML refers to Hyper Text Markup Language.

Open System Interconnection dictates how the internet works. OSI has layers for internet purposes. Osi includes physical, data link, network, transport, session, presentation, and application functions. Routers and modems have protocols as well to determine efficient network pathways to other networks.

Although websites are independent of the internet, the World Wide Web (www.) is a global collection of websites containing information accessed via the internet which can be interconnected and hyperlinked together. The world wide web requires each site to have a Uniform Resource Locator (URL) including a domain name and other information giving it a unique internet protocol (IP) address.

Eberling@www.thndrsns.com

Algorithms

Discussed to this day is whether the universe is composed of mathematical equations required to adhere to or is math our invention describing and predicting the cosmos. One definition of mathematics is the science of numbers pertaining to quantity, space, and time. Algorithms may perhaps be a system of math and can certainly be used for it but deals primarily with cause and effect. If this happens then that will probably if not certainly be made to or will happen as the result.

Preliminary examples of math are keeping count. If there are three marbles in a pile and two more are put in the same pile mathematics concludes there are now five marbles in that pile. When four are taken away one marble is left.

Likewise, fundamental algorithms can also be used for sorting. Given a bag of different colored marbles the first one taken out is put in a first pile, maybe it is blue. If the second marble taken out of the bag is blue it is put in the first pile but it if it is not, say yellow then placed in a second pile. Now the algorithm gets complicated. If the third marble out of the bag is blue it is put in the first pile and if yellow in the second pile but if not either color by being red then it’s located in a third pile. So forth and so on until no marbles remain in the bag. This algorithm makes it simple to count how many of the same colored marbles there are. Webster defines algorithms as a step-by-step procedure for solving a problem or accomplishing some end.

In the above illustration every time a marble is taken out of the bag and decisions are made which pile to put it in is called a loop in the computer world. Integrated electronic computers are extremely fast now capable of performing over a billion loops a second. Given a million marbles these computers can communicate how many marbles of each color are in a bag as soon as the enter key is pressed. Although modern computers are extremely fast they must follow direction of logic and reason.

Electronic computers may be a recent invention but math and algorithms are not. Evidence of counting is found in prehistoric human history before written records can be deciphered to make significant sense of. Wooly mammoth bones or the like have been found with columns of nicks cut in them equal distance apart indicating math and algorithms. Documented logic and reason will not happen until later ancient civilizations.

Evidence of early man have been found dating over a million years ago in north Africa and China. Prehistoric humanoids often referred to as cavemen are considered to be from 700,000 to 200,000 years in the past. They may not have had a conscience concept of logic and reason although religions were being developed. This required a belief in supernatural entities to make sense of why the world exists as it does and subsequently establish a social order. The ones who understood and could explain it best are called Shamans.  This era is also referred to as the stone age. These primitive people spread across the globe.

With discovery of processing metals to make better tools and weapons began the Bronze Age dating back 2,500 years B.C. (Before Christ) or B.C.E. (Before Common Era), whichever is preferred, resulting in ancient civilizations. The Bronze Age lasted until the 1100 B.C. when iron and steel are made. Babylonia originated in the early Bronze Age and ancient Egypt in 1550 B.C. The Xia Dynasty predates 2,000 B.C.E. in China dividing the continent into western and eastern regions. Religions ruled with supernatural deities now referred to as gods. Usually one deity in particular dominated over the others. Evidence of Hinduism is found 4,000, Buddhism 2,500, and Judaism 2,000 B.C.E. Legend has it the supreme Greek god Cronus was defeated by his son Zeus. It can’t be proven one way or other whether these transcendental entities exist or not but societies believing in them appear to outlast others that don’t.

Not until after discussion of philosophy by ancient Greeks and others that the Hebrew concept of only one god began to dominate modern society by Jesus in the first century, Buda the fifth, and Mohammad during seventh century A.D. or C.E. putting an end to Pharos, Caesars, Emperors, Shoguns, Kings and Queens demanding to be exclusive descendants of Gods.

Algorithms could care less about history and religion. They do with logic and reason. Religions are now included in philosophical metaphysics because belief can neither be intrinsically proven nor disproved mathematically. However, there seems no point in discussing philosophy and algorithms without knowing how they evolved.

Logic is an ancient Greek word used by its philosophers. The most well-known are Socrates, Plato, and Aristotle. Confucius was doing the same at the time in China around 500 B.C.E.  Philosophy is defined as the pursuit of wisdom, reason and understanding by applying logic. Not only did these theorists attempt to explain cause and effect but apply it to make decisions.

For example: In a game of marbles should the blue or red one be used to shoot with to achieve best results. This is easier to keep track of by listing the reasons for the blue one on the left side of a paper and for the red on the right side and likewise for not using the blue on the left and red on the right. This can be pictured to look like a diagram of a family tree. Pros and cons are subdivided for each reason and numbered from 1 to 10 ranking importance with positive numbers for and negative numbers given to reasons against. By adding and subtracting all the numbers on the left side of the paper and those on the right logic determines whether a blue marble or a red one has the highest probability of winning and should be used. This paper is called a flow chart explaining algorithms.

These philosophers also concluded it probably don’t matter if the blue or red marble is used to shoot with and may be best left to chance by flipping a coin. An attempt to use flow charts to make decisions in government became long and complicated with a vast number of citizens having reasons for and against when deciding an issue. It was concluded voting is more effective for wellbeing and satisfaction of society as a whole. Hence the idea of democracy was established.

Philosophy embracing collective reason as the path to contentment came to an end with territorial expansion of Alexander the Great conquering the vast territories of Macedonia in 323 B.C. extending from northern Greece to what is now Yugoslavia and Bulgaria. Alexander’s view of divide and conquer was also applied his army and a military divided was of little use. Although different opinions might be considered it became necessary for him to make final decisions how they all were to perform. The Roman Empire dominated not long after that with Caesars claiming absolute authority until its fall in 476 A.D. in the Common Era. Their philosophy basically revolved around aesthetics relating to sensory sensations of beauty and enjoyment.

A computer is a devise for calculating, processing, and storing data. An early device of this nature is the abacus dating back 2400 B.C. in Babylonia. This apparatus has a series of vertical rods supporting five beads on the bottom separated by a barrier from beads on the top. The reason for five is not hard to figure out since there are five digits on one hand. An abacus not only keeps count but can be used for adding and subtracting as well as multiplying and dividing. Modern slide rules also calculate trigonometry and calculus.

Paper may not be a computer in the sense it does not perform computations but assists in it and certainly stores information more easily shared with others. Paper was invented by Egyptians using papyrus plants. Although that paper was thick and heavy it was much easier to write on with ink made of other plants and minerals than carving and painting on sandstone. The Chinese further refined this process using plants growing there. Arabs got hold of this development finding methods to make it as durable and thin increasing their enlightenment and conquests. Arabic numbers are now used replacing Roman numerals. German invention of the printing press started the modern industrial revolution resulting in positive and negative consequences.

At first electric computers weren’t that great and were large and bulky but by using motors they could move mechanical objects around much faster than by hand. It wasn’t until development of electronics that things started rolling. Initially resistors, capacitors, transducers, diodes, and transistors were relatively large but smaller than vacuum tubes. The race is on figuring how to make them more miniature resulting in microchips made up of many of these components in a space smaller than a button on a remote control. They can’t handle much electrical current but that isn’t necessary to operate logical functions. Electricity is extremely fast moving at the speed of light at approximately 186,000 miles per second in a vacuum. Maybe not that fast in metals and silicon but electrons don’t have far to go in microchips.

These extremely small components are used to build electronic gates to determine logical functions. Let’s say one microvolt represents one, on, yes, or true. Then zero or absence of voltage represents off, no, or false. Given two inputs or circuits a simple logic gate has one output. An AND gate requires both circuit feeding it to have a microvolt for a microvolt to leave it. A OR gate requires one, the other or both incoming circuits to have a microvolt for a microvolt to exist on the output. The opposite being NAND and NOR gates. When both inputs are one to a NAND gate the output will be zero and in a NOR gate if any or all of the inputs are one the output will be zero. Depending on how logic gates are interconnected interprets if this and this is true or not true, and that and that might be or not be true, they will determine whether the outcome is true or false.

This all seems impossible although made easier by Boolean algebra resulting in computer programming and coding. Morse code used by crystal radios and telegraph lines is an example. When a switch at one end is taped or pressed creating dots and dashes it causes a light bulb to blink or speaker to make static sounds. Each letter in the alphabet and number is assigned a unique sequence of dots and dashes sent electrically and interpreted back to English at the receiving device. Instead of dots and dashes electronic computers use zeros and ones for coding.

The two basic microchips in a computer are Read Only Memory (ROM) and Random Access Memory (RAM). ROM chips are hard wired meaning their logic can’t be altered. They are used to determine the basic operating characteristics of a computer called firmware. Logic in a RAM chip can be changed by computer programming referred to as software. All computer applications (APPS) are software determined by program coding and algorithms. Computer memory is stored in registers.

There are many types of software computer languages using different coding symbols found on a keyboard the computer understands telling it what to do. If this happens then that will happen. Cause and effect. If Yoda is moved to a location on the computer screen inhabited by an evil wizard he could be gobbled up.

Which came first, the chicken or the egg. Human brains are capable of processing a lot of information and making many decisions based on it a minute. Is the universe made of up of algorithms it must adhere to or are they one way for us to explain and predict it? Our DNA is a genetic code full of algorithms.

Steve Eberling @ www.thndrsns.com

SOLAR ELECTRIC SYSTEMS

Energy produced by the sun has been used to improve our lives since ancient times. Early housing was constructed facing it for heat and more daylight through openings or windows. The sun was regarded a deity by all cultures. Known life cannot exist without its radiation and gravitational pull. Huge pyramids built thousands of years ago have openings correlating to the sun’s position during summer and winter solstices or other times of year considered important. It was thought the sun moved across the sky.

Modern understanding of our solar system and outer space is considerably different with exception of life’s entire dependence on this star. Thought to exist in the current state for four billion years the sun will continue doing so the same amount of time. Although slightly over one-hundred times earth’s size, compressed density makes its mass nearly ninety-nine percent of all orbiting planets.

Radiation and gravity go the speed of light traveling ninety-three million miles to earth in over eight minutes. Some radiation bounces off the atmosphere although one-thousand watts per square meter deposit on this planet’s surface on a clear day, as much electrical energy people use in a year. Heat and vegetation produced by it are abundant.

PHOTOSYNTHESIS
Plants make their own food by photosynthesis. Vegetation converts light into chemical energy by absorbing carbon dioxide from air, making sugars and oxygen. In comparison mammals, reptiles, fish and insects breath oxygen, eat sugars and exhale or deposit carbon. The cycle of life totally depends on light radiated from the sun.

Green plants contain chlorophyll proteins which ironically absorb light from either side of the visible spectrum. Being in the middle, green and yellow are left to reflect making these plants appear that color. When red and blue lights are absorbed, chlorophyll separates water into hydrogen and oxygen. Hydrogen bonds with carbon dioxide forming glucose sugars and oxygen releases into the air. Our atmosphere consists of seventy-eight percent nitrogen. Temperature is a variable for all life forms.

When plants and animals decay carbon remains and when concentrated by fossilization under heat and pressure for a long time become coal, natural gas and oil which burn hot producing heat or mechanical and electrical energy. Under extreme conditions carbon transforms into diamonds, the hardest substance on earth. It is estimated there are hundreds of millions of diamonds in earth’s crust buried too deep to extract.

LIGHT WAVES AND PHOTONS
The sun is basically a massive nuclear reactor fusing hydrogen atoms into helium, converting four million tons of matter into energy per second. When this energy eventually escapes sun’s gravity it radiates at various wave lengths. Longer ones are infrared with shorter ultraviolet and X-rays. Visible light to us is only a short span somewhere in the middle. All waves have a velocity of 186,282 miles per second in a vacuum in outer space. First it was thought radiation is strictly waves, but then realized light bends toward objects with large gravitational pull. Einstein concluded light is made of both waves and particles in his theory of relativity. These particles are called photons with no measurable mass or electric charge. Photons are attributed for exchanging electrons between molecules in photosynthesis and passing electrons from one substance to another in electric solar systems.

PHOTOVOLTAICS
Tangible matter is made of tiny atoms. Atoms contain protons and neutrons forming a nucleus with electrons orbiting around at different distances. Several electrons can be the same distance by orbiting at different angles imagined as clouds or shells. The outer most is the valance orbit. Protons have a positive, neutrons none, and electrons a negative charge. Depending on composition different elements form. They combine into molecules, carbon dioxide and water for example. Electromagnetic force is extremely stronger than gravity at small atomic levels.

Atoms with more protons than electrons have a positive charge and those with more electrons a negative charge. The difference often occur in the outer valance shell. Substances consisting of equal proton and electron charge are semi-conductors. These are made to charge one way or other by adding small amounts of atoms from other material.

Crystalline silicon might not be the best semi-conductor but is abundant and easy to manufacture. Silicon’s ability to stop or allow electricity is essential for computer chips. Originally shining light on some metals produced small amounts electricity. Transparent silicon is more efficient.

SOLAR PANELS
Solar panels are made of several modules subdivided into solar cells. Each cell by itself doesn’t produce much energy. It’s common for sixty cells in a module connected in series, plus to minus, resulting in substantial voltage. Twelve volts is one standard for direct-current. Twelve volt batteries are used in cars. Modules can be connected in parallel by tying negative and positive connections together increasing amperage. The panel is covered with a transparent sheet and solid backing. Several panels connected parallel at a fused combiner boxes make arrays providing more available electricity.

Solar cells made of semi-conductors convert sunlight into electricity. One semi-conductor layer is mixed, called doping, with material having less electrons than protons. Positively charged the P side is bonded by a layer not doped to the N side mixed with extra electrons. The layer in the middle is neutral forming a P-N junction. Photons excite extra electrons displacing them from silicon on the N side. When connected by a wire they want to fill vacant electrons called holes on the P side creating a potential difference across the P-N junction. Voltage forces electrons back to the N side repeating the cycle. If a wire feeds resistive and inductive loads, voltage potential is measured across those devices as well. Solar panels produce direct-current in one direction.

Some solar panels are more efficient than others producing more electricity with the same amount of irradiation. Conversion efficiency is calculated by short circuit current, open circuit voltage and fill factors. Depending on type of silicon and how it’s doped determines electron movement by photons from different light frequencies. Expensive panels have cells with several layers of different semi-conductors increasing electrical production. Panels with transparent coverings resistive to glare but reflecting infrared rays are better. Infrared rays create heat without displacing electrons by photons. Solar panels work best at lower temperatures.

PHOTOVOLTAIC SYSTEMS
Photovoltaic or PV systems are proper names for solar electric systems.

The simplest system connects twelve volt devises such as heaters, lights and motors to twelve volt panels. They only operate when sun shines. Adding battery backup charged by some electricity produced allows operation for a while during night or on cloudy days. An advantage for lights at night and locations without power lines, satellites being an extreme example. Controllers prevent batteries from over or under charging. Trade off exists between size of panel or array and number of batteries. No point installing more batteries than panels can charge. Automotive batteries work but lead-acid, deep-cycle ones are made for this purpose charging up to eighty percent storage capacity. Larger solar panels can output much more than twelve volts.

Inverters added to photovoltaic systems decrease or increase voltage and changes direct into alternating current. 120 and 240 volts at 60 cycles per second are standard. Inverters aren’t complicated like variable drives because only one voltage and frequency are created. Inverters should be capable of suppling circuit breakers protecting smaller wires to ac loads. Unless other production sources are connected to PV wiring, it is called a stand-alone photovoltaic system.

Without many solar panels, arrays produce only enough electricity for some devises or supplement energy delivered by generators, windmills and utility companies. Tying sources together requires computer controlled power conditioning equipment insuring electricity is all the same voltage with frequencies in phase. Companies generally supply most power for property and houses, but electricity from other sources reduce that amount lowering utility fees. Renewable energy provided by sun and wind is considered free.

PHOTOVOLTAICS AND THE NEC
The National Electric Code doesn’t determine how solar power is made but that it’s installed efficient and safe. The NEC (NFPA 70) is one volume in an extensive library published by the National Fire Protection Association dedicated to preventing, restricting damage and stopping fires. NFPA also concerns safety for fire fighters and other emergency responders.

Photovoltaic systems are addressed by Article 690 in Chapter 6 titled Special Equipment in the NEC. General Requirements in Part I necessitate installation of PV equipment and all associated wiring and interconnections be performed only by qualified persons with skills, knowledge and safety training to recognize and avoid hazards involved. However, electricians and homeowners become involved with PV systems during troubleshooting and maintenance.

Solar panels exposed to sunlight continue to produce voltage. Voltages often exist on both sides of disconnect switches when other production sources and inverters interconnect. Parts VII & VIII of Chapter 6 make clear Energy Storage Systems and Interconnected Electric Power Productions Sources be installed according to Special Conditions in Chapter 7. PV stand-alone systems are addressed by Articles 690.10 and 710.15.

Throughout the electrical code requirements for circuits, disconnection devices, wiring methods, grounding and bonding, and marking depend on the type of installation. Requirements become complex with PV systems comprised of different voltages and currents. Equipment and components are listed or field labeled appropriate for photovoltaics. Disconnect switches subject to electrical back feeds are suitable and labeled for that purpose. Polarity for direct-current branch circuits more than 60 volts are identified according to Article 210.5(C)(2) with red positive (+) wires and black negative (-) ones or accurately labeled.

Assuring safety for fire fighters, first responders and maintenance personnel, many PV circuits need ground fault or arc fault protection. Inverters and power conditioning equipment contain capacitors storing energy necessitating means of rapid shut-down limiting power output to less than 30 volts and 240 watts within 10 seconds. Disconnects are put at solar panels and between its equipment. The main PV disconnect switch initiates rapid shut-down of the entire system in or on a building, labeled to code and located next to the utility main panel easily found by firefighters. PV service panels also operate remote-controlled disconnects to completely protect buildings from photovoltaic systems. PV system dc circuits cannot be greater than 600 volts on or in one and two family dwellings. Exception for rapid shut-down is made for buildings only containing PV equipment.

CONSIDERATIONS
Solar powered systems are efficient and productive in some geographic locations more than others. Lower latitudes closer the equator receive more daylight and higher altitudes with thinner atmosphere allow more sunshine. Angles solar panels are mounted vertically depend on geographic latitude, although sun is higher during summer than winter months. Solar panels do not work when covered by snow.

Sun’s radiation naturally heat buildings and blocking it with panels mounted on roof tops might be a good idea in the south but create a dilemma farther north. Air conditioning often require more electrical consumption than heating given many furnaces burn fuels. Solar panels mounted on structures away from buildings have an advantage for programmable tracking systems using electric motors to position panels toward the sun as its location changes during the day and throughout seasons.

When a building produced more electricity than used meters ran backwards lowering if not reversing utility costs. Electronic meters are smarter detecting this occurrence. Some electric companies do not refund the difference. Others might but don’t pay the same as they charge to provide it. Some locations where consumption is growing faster than electricity is produced give significant financial incentives to homeowners installing photovoltaic systems. Cost of solar installations compared to utility savings over a period of time at different locations determine efficiency. Solar panels are expected to last about thirty years.

Storage batteries emit toxic vapors possibly creating explosive mixtures, particularly when charging. The room they’re in must have sufficient ventilation eliminating these hazards and have an entrance door designed for quick exit. Not a bad idea housing lead-acid batteries outdoors. Solar battery back-up is certainly an advantage during power outages to keep lights and furnaces working.

Global warming by burning carbon fuels is a prevalent concern and using sun’s energy a popular idea. People want to do their part. Good news is, as solar and wind generated power becomes more efficient with less installation costs industrial companies are finding it economical installing solar and wind farms instead of massive power plants requiring substantial maintenance and large quantities of expensive, transported fuel.

Eberling@www.thndrsns.com