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Electronics Engineering
Electronics Engineering is a branch of engineering that deals with practical applications of electronic components, devices, systems, or equipment. Electronics are devices that operate on low voltage sources, as in electron tubes, transistors, integrated circuits, and printed circuit boards and use electricity as part of its driving force.
24,372 Questions
How much did he first desktop computer cost?
The first computers had no fixed selling price. They were usually built on cost plus fixed fee contracts, because the people making them could not guess at final cost to build them.
For example the ENIAC was estimated at $50,000 when the Army signed the cost plus contract. The Army eventually payed a bit more than $500,000.
The UNIVAC I original fixed price contracts were for $250,000 but when the machine went into production its actual price was $2,500,000. Remington Rand lost lots of money on the first two UNIVAC's sold as the company had to pay the difference between cost to build and what the customer payed!
Why you use silicon chips in computers?
why we use silicon chips in computers?
- Silicon is cheap, it comes from sand.
- Silicon has a very wide operating junction temperature range (-55C to +150C).
- Silicon is very easy to process to make transistors and ICs.
- Silicon dioxide is an insulator, no other semiconductor has a solid insulating oxide.
- When circuits are built on a silicon chip they are either analog or digital building block circuits.
- The digital building blocks naturally build computers (especially now that we have building blocks as large as whole multi-core CPUs, etc.).
Before semi-conductors were used in computers, they had to use vacuum tubes which cost a lot, took up a lot of space, burned out quickly and so were unreliable, and used a lot of electricity. We could not have the modern computer without chips.
they are;small,compact and portable.
Silicon is the easiest elemental semiconductor currently usable to make ICs with. One of its most important properties is its oxide and nitride are insoluble solid insulators, this is not true for either germanium or carbon the other elemental semiconductors. Also silicon has a good operating temperature range (junction temperature up to 150C), germanium has much lower range and although carbon (as diamond) has much higher range (junction temperature up to 600C) it is too brittle for current process machines. All other semiconductors are alloys and are tricker and more expensive to process than elemental ones. Most important silicon is almost free, it can be extracted from any sand, the parent rock of sand, and of course sandstone which is made of sand.
What advantage over vacuum tubes did transistors represent in computer design?
From an audio amplifier standpoint, transistors were primarily low-voltage, high current devices. Since loudspeakers were typically low-impedance, the transistorized circuit didn't require a transformer to help match the impedance; i.e. they were better matched. However, when a transistor "saturated" it "clips" abruptly, causing harmonics at the output. Vacuum tubes tended to "soft clip' which reduced the undesirable harmonics.
From another standpoint, transistors were smaller in size, didn't require high voltage power supplies, and dissipated less heat (i.e. more efficient).
Analog computers are also called continuous computers, as there are no discontinuities in their computations. A mechanical analog computer might represent variables by rotation rate of shafts, any given shaft can rotate at any speed and will smoothly accelerate or decelerate its rotation as the calculation proceeds. An electronic analog computer might represent variables by voltages, say any voltage between -20VDC and +20VDC with voltages smoothly varying as the calculation proceeds.
- Bush differential analyzer at MIT, electromechanical, 1929.
- Norden bombsight, electromechanical, 1930s through 1960s (used in WW2, Korea, and Vietnam!).
- Various commercial electronic differential analyzers sold from 1950s through 1970s, electronic.
- Murray/Walker simultaneous equation solver, electronic, 1949.
- Vacuum operated cruise control in cars, mechanical/pneumatic.
- Resistor/capacitor 3D mesh water table models, electronic.
- etc.
Digital computers on the other hand have discontinuous states that they jump from one to another.
- ABC: Atanasoff-Berry Computer, simultaneous equation solver, 1942
- ENIAC, late 1945
- UNIVAC I
- IBM 700 and 7000 series
- DEC VAX
- Desktops and laptops
- Both of the computers in your cellphone
- etc.
Hybrid computers are simply computer systems that combine both analog and digital computers together. Usually the digital computer controls the analog computer, reconfiguring it and entering new data each time the analog computer completes one problem, to have it solve a different one.
- Most were custom "one off" systems built by individual labs or universities by buying a standard COTS digital computer and a standard COTS electronic analog computer, and customizing them to work together as needed.
- One example of such a machine used a DEC minicomputer and an analog computer to model heat flow from a nuclear reactor fuel rod to circulating coolant. The analog computer was programmed on its plugboard to do a rapid solution through a single radial slice of the system, the digital computer was programmed to enter new parameters into the analog computer for each slice starting at the coolant entrance end of the fuel rod and collect and record the results of each slice. The machine could solve the problem to adequate accuracy much faster and more cheaply than an all digital system or all analog system of the time period.
Why the first-generation of computer use vacuum tubes?
- The first digital computer that used vacuum tubes was the ABC, completed in 1942 by Dr. John Vincent Atanasoff and Clifford Berry in Ames, IA.
- An early analog computer that used vacuum tubes was the Differential Analyzer, completed in 1929 by Vannevar Bush and a large team at MIT. (there probably were other smaller analog computers of this type that used vacuum tubes before this, so it probably isn't the first but its the earliest where I can find it clearly documented).
When was radar first used in world war 2?
One of the first uses was during the Battle of Britain. British radar would detect oncoming German airplanes and the British would send up the Supermarine Spitfire to shoot down fighters and the Hawker Hurricane to shoot down bombers. Radar let the British use their aircraft to their best advantage. Instead of constantly flying air patrol, they could take off when the enemy was coming, and attack them where they were. It was the advantage of radar that enabled the British to defeat the Germans and showed once and for all time, the importance of radar in air combat.
What happens to the current in a circuit when the resistance is increased?
The flow of electrons meets an increased impedance to it's flow.
Where was the overhead projector invented?
A man named Jenkins, not sure of the first name, made various technical improvements in Movie Projectors in the twenties. He was also an aircraft pilot of the experimental type- light seaplanes, as I recall, and WA ssomething of a TV pioneer as well, a versatile inventor! Jenkins Radiovision was his big, but somewhat obscure (Hit) a form of television device.
Is the word North Star capitalized?
Yes, it is a word. I am almost completely sure it is the study of astronomy.
The time constant of a circuit that contains inductance and resistance follows what type of curve.?
1.cosine 2.exponential
3.min-max value
4.sine
What is the function of an IC UM3561?
it is used to generate 4 kinds of sounds-police siren,fire alarm,ambulance and gun siren
Purely additive. 2+3+4+5+6=20.
Least Significant Bit. Least Significant Byte. (Depends on use.)
Do LCD TVs use cathode ray tubes?
Some early flat screen TVs used cathode ray tubes, but the flat faced tubes were harder to make and heaver than the older curved faced tubes. When newer designs (e.g. plasma, LCD, LED) came out that naturally produced flat screens and were lighter weight than cathode ray tubes, they rapidly made flat screen cathode ray tube TVs obsolete.
What the advantages of active and passive device?
An active device is any type of circuit component with the ability to electrically control electron flow (electricity controlling electricity). In order for a circuit to be properly called electronic, it must contain at least one active device
Can more than one resistor be used in a circuit?
Yes, more than one resistor can be used in a circuit. Resistors can be connected in series, where their resistances add up, or in parallel, where the total resistance decreases. This allows for greater control over the current and voltage levels within the circuit, enabling designers to achieve desired electrical characteristics. Using multiple resistors can also help in managing heat dissipation and improving circuit functionality.
What is stability of transistor?
Transistors need thermal stabilization because the operating point of a transistor junction, similar to a diode, is affected by temperature. In fact, this can cause thermal runaway, and device destruction, if the circuit design does not compensate for this.
Answer mostly correct but the operating point of a transistor must remain fixed as temperature varies whether going low or higher. that is mainly the concern about. not runaway that is caused by bad design.
What are composite signals why you needed?
In case of TV broad casting, the Video Signal is not transmitted alone, but it accompanied by a number of other signals or pulses, which help the exact reproduction of the picture at the receiving end. These pulses include Blanking Pulses, Synchronizing pulses and Equalizing pulses. A combination of Picture signal and other Controlling signal or pulses is called Composite Signal. Thus Composite Video Signal may consist of Following Parts.
- Picture information (Data)
- Blanking Pulses (Delay Pulses)
- Vertical and Horizontal Synchronizing Pulses (controlling Pulses)
Generally,
A Combination of Data and Other Controlling Signal is Called Composite Signal .
Inductive reactance is equal to capacitive reactance?
yes,they are equal at only one condition i.e. when the circuit containing R,L and C in series or in parallel behave as a purely resistive circuit. This condition occur only at resonance.
What is the advantage of opto-isolator?
An opto isolator is an electronic device that prevents high voltages from components in one side of a circuit from damaging or interfering with components on the other side of the same circuit.
Is there a magnetic field around current carrying conductors?
yes.magnetic field present around the conductor.
current and magnetic fields are inter related..
with current we can produce magnetic field and vice versa
