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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
Interactive Voice Recorder (IVR) is a technology used in the field of telecommunications to improve customers' experience by presenting information and options to callers using pre-recorded voice prompts and menus mainly to handle high call volumes.
Characteristics of relaxation oscillator?
A "Relaxation Oscillator" is an "R/C" oscillator, in which a Capacitor is charged from a DC (Direct Current) fixed voltage source, through a resistor.
Connected across this Capacitor is a "device" that, initially, does NOT conduct any current. But when the Voltage on the Capacitor reaches a certain value (depending upon the characteristics of the "device") the "device" will "break down" or "avalanche", or suddenly drastically decrease in resistance.
This causes the "device" to quickly start to discharge the Capacitor. However, when the Voltage across the Capacitor and its parallel connected "device' decreases with the discharge cycle, the "device" will suddenly return to its "non-conducting" state, and the Capacitor again begins to re-charge.
The Capacitor again reaches the "break down" voltage of the "device", and the process continues, thus effectively creating "oscillations".
One version of this circuit uses a simple Neon lamp (such as a NE-1) as the "device". Typically, the "break down" or "ignition" voltage of a neon lamp is around 70 volts. At this point, the gas in the lamp "ionizes", becoming highly conductive.
However, when this voltage drops (as the lamp discharges the Capacitor) to about 50-60 volts, the lamp "goes out" (the neon gas is no longer ionized or conducting), and the Capacitor again starts to charge through the resistor.
This form of the "Relaxation Oscillator" will not operate at high frequencies (such as Radio Frequencies), and was often used to just generate a "flashing light" (the Neon lamp).
With the advent of semiconductors, a device called the Unijunction Transistor (UJT) was developed. It contained three leads, the Emitter, Base 1, and Base 2.
The junction of the Resistor and Capacitor is connected to the Emitter, with the "bottom" of the Capacitor (and the negative side of the Voltage Source) connected to Base 1 Base 2 is connected to the positive side of the Voltage Source.
Again, when the voltage on the Capacitor reaches the "break down" level, the UJT's "resistance" between the Emitter and Base 1 drastically drops, discharging the capacitor. However, when the discharging current through the UJT drops below a certain level, it again develops a high resistance between its Base 1 and the Emitter, and re-charging of the Capacitor begins again.
UJT circuits can operate at higher frequencies than the Neon bulb circuit. Often a resistor is inserted between Base1 and the common or negative side of the voltage source, and the resulting discharge current produced voltage across this resistor is used to trigger other devices. Also, the voltage waveform across the Capacitor approaches a linear "sawtooth" waveform (depending on circuit component values), but not nearly as linear as other approaches.
"Devices" of this type are considered to have a "negative resistance" characteristic, which is another discussion in itself.
When one bulb is unscrewed in a series circuit does the other bulb stay lit?
You break the circuit and they both extinguish (go out).
Answer: The circuit will open up causing the current to quit flowing to both bulbs therefore there will be no lighted bulbs
CommentYou also have the full supply voltage appearing across the empty lampholder!
According to Ohm's Law how is voltage related to resistance and current?
1). Voltage = (resistance) x (current)
2). Current = (voltage) / (resistance)
3). Resistance = (voltage) / (current)
I think #2 is Ohm's original statement, but any one of these can be massaged algebraically
in order to derive the other two.
What is the difference between atmega and pic micro controller?
atmel is more cheaper and easy to use.. the programmer is also easy to built and try...
Can dc current work on transformer?
Transformer is by definition can transform only AC current. But it's possible to build device that can step up or step down DC voltage directly. These are called DC-DC converters not transformers.
DVD is the work of many companies and many people. DVD evolved from CD and related technologies. Some of the early proposals for "high-density CD" were made in 1993, and these efforts gradually coalesced into two competing proposed formats. The MMCD format was backed by Sony, Philips, and others. The SD format was backed by Toshiba, Matsushita, Time Warner, and others. A group of computer companies led by IBM insisted that the factions agree on a single standard. The combined DVD format was announced in September of 1995, avoiding a confusing and costly repeat of the VHS vs. Betamax videotape battle or the quadraphonic sound battle of the 1970s. No single company "owns" DVD. The official specification was developed by a consortium of ten companies: Hitachi, JVC, Matsushita, Mitsubishi, Philips, Pioneer, Sony, Thomson, Time Warner, and Toshiba. Representatives from many other companies also contributed in various working groups. In May 1997, the DVD Consortium was replaced by the DVD Forum , which is open to all companies, and as of February 2000 had over 220 members. Time Warner originally trademarked the DVD logo, and has since assigned it to the DVD Format/Logo Licensing Corporation (DVD FLLC). The written term "DVD" is too common to be trademarked or owned. See section 6.2 and visit Robert's DVD Info page for links to Web sites of companies working with DVD. The official DVD specification books are available after signing a nondisclosure agreement and paying a $5,000 fee. One book is included in the initial fee; additional books are $500 each. Manufacture of DVD products and use of the DVD logo for non-promotional purposes requires additional format and logo licenses, for a one-time fee of $10,000 per format, minus $5,000 if you have already paid for the specification. (E.g., a DVD-Video player manufacturer must license DVD-ROM and DVD-Video for $20,000, or $15,000 if they have the spec.) Contact DVD Format/Logo Licensing Corporation (DVD FLLC), Shiba Shimizu Building 5F, Shiba-daimon 2-3-11, Minato-ku, Tokyo 105-0012, tel: +81-3-5777-2881, fax: +81-3-5777-2882. Before April 14, 2000, logo/format licensing was administered by Toshiba. ECMA has developed international standards for DVD-ROM (part 1, the smallest part of the DVD spec), available for free download as ECMA-267 and ECMA-268 from http://www.ecma-international.org/ . ECMA has also standardized DVD-R in ECMA-279 , DVD-RAM in ECMA-272 and ECMA-273 , and DVD+RW as ECMA-274 (see 4.3 ). Unfortunately, ECMA has the annoying habit of spelling "disc" wrong. Also confusing, if you're not from Europe, is ECMA's use of a comma instead of a period for the decimal point. The specification for the UDF file system used by DVD is available from http://www.osta.org/ . Many technical details of the DVD-Video format are available at the DVD-Video Information page. Any company making DVD products must license essential technology patents from the " 3C ' pool (LG, Philips, Pioneer, Sony: 3.5% per player/drive, minimum $3.50; additional $0.75 for Video CD compatibility; 5 cents per disc), the " 6C " pool (Hitachi, IBM, Matsushita, Mitsubishi, Time Warner, Toshiba, Victor: 4% per player/drive, minimum $4; 4% per "DVD Video decoder", minimum $1; 7.5 cents per disc) and from Thomson (~$1 per player/drive). Patent royalties may also be owed to Discovision Associates , which owns about 1300 optical disc patents (usually paid by the replicator). The licensor of CSS encryption technology is DVD CCA (Copy Control Association), a non-profit trade association with offices at 225 B Cochrane Circle, Morgan Hill, CA. There is a $15,000 annual licensing fee, but no per-product royalties. Send license requests to css-license@lmicp.com , technical info requests to css-info@lmicp.com . Before December 15, 1999, CSS licensing was administered on an interim basis by Matsushita. Macrovision licenses its analog anti-recording technology to hardware makers. There is a $30,000 initial charge, with a $15,000 yearly renewal fee. The fees support certification of players to ensure widest compatibility with televisions. There are no royalty charges for player manufacturers. Macrovision charges a royalty to content publishers (approximately 4 to 10 cents per disc, compared to 2 to 5 cents for a VHS tape). Dolby licenses Dolby Digital decoders for approximately $0.26 per channel. Philips, on behalf of CCETT and IRT, also charges $0.20 per channel (maximum of $0.60 per player) for Dolby Digital patents, along with $0.003 per disc. Dolby also licenses 2-channel Dolby Digital encoders. Dolby licenses MLP decoders for DVD-Audio players. An MPEG-2 patent license is required from MPEG LA (MPEG Licensing Adminstrator). Cost is $2.50 for a DVD player or decoder card and 4 cents for each DVD disc, although there seems to be disagreement on whether content producers owe royalties for discs. Many DVD players are also Video CD (VCD) players. Philips licenses the Video CD format and patents on behalf of themselves, Sony, JVC, Matsushita, CNETT, and IRT for $25,000 initial payment plus royalties of 2.5% per player or $2.50 minimum. Nissim claims 25 cents per player and 78/100ths of a cent for parental management and other DVD-related patents. Various licensing fees add up to over $20 in royalties for a $200 DVD player, and about $0.20 per disc. Disc royalties are paid by the replicator. Royalties for DVD+R patents are charged by Philips (approximately $0.06 per disc) and Sony (1.5 to 3.5% of disc price).
The result was the DVD specification, finalized for the DVD movie player and DVD-ROM ... The DVD Video format was first introduced by Toshiba in Japan in ..... have purchased legitimate media are made to watch the anti-piracy warning. ...
DVD-R - DVD-Video - DVD+R DL - DVD-RW
Why intrinsic semiconductors are not used in practice for manufacturing of electronics devices?
The main reason semiconductor materials are so useful is that the behavior of a semiconductor can be easily manipulated by the addition of impurities, known as doping. Semiconductor conductivity can be controlled by introduction of an electric or magnetic field, by exposure to light or heat, or by mechanical deformation of a doped mono-crystalline grid; thus, semiconductors can make excellent sensors. Current conduction in a semiconductor occurs via mobile or "free"electrons and holes. collectively known as charge carriers. Doping a semiconductor such as silicon with a small amount of impurity atoms, such as phosphorus or boron. greatly increases the number of free electrons or holes within the semiconductor.
It can be make in very small size and the electronics device are small in size that why the semiconductors are used in electronic devices.
The above explains HOW semi conductors work.
The reason for WHY they are used is, what's the alternative?
The only alternative is thermionic valves (tubes).
Tubes fell out of favour for many reasons.
They run hot
Made of glass and delicate,
Heavy
Large
Consume lots of power
Need high voltages.
Semi conductors are the opposite of all of these.
How do you convert a 50 micro-amp DC meter to a 100 milli-amp meter?
with a resistor 300K in series with the 50 micro amperes DC meter
What happen to the energy stored in the capacitor while the capacitor is discharging?
It flows out of the capacitor into the external circuit
Is any difference between capister and condenser?
Actually, there is no difference as they are just two names for the same device.
The term condenser is older, and was used extensively in the automotive and internal combustion industries for a part name in ignition systems.
The term capacitor [often referred to as a "Cap"] is newer and more often used in the electronics industry.
Although there are many different types and materials, they all are basically nothing more than two sheets of Aluminum foil separated by a nonconductor material [in simple Caps, nothing more than waxed paper].
How current electricity moves in a circuit?
You need a source of electrical potential difference, also known as voltage (which is the technical term for what for you call "electric pressure"). The easiest and most common voltage source is a household battery. Hook up the positive electrode of the battery using a conductor (eg. a copper wire) to one end of your circuit and the negative electrode to the other end, and voila, you'll have electric current flowing through your circuit.
What is the total resistance in a parallel circuit with a 10 ohm lamp and a 15 ohm lamp?
Well, first of all, it's the current that's "going through" the wire, not the voltage.
The voltage is just the difference in pressure between the two ends, and that's
what makes the current want to go through it, towards the lower pressure. But
we understood what you meant in the question.
From Ohm's Law, [ I = E/R ] . (Current = voltage divided by resistance.)
I = (10)/(5) = 2 amperes.
You might not want to try this at home. The power dissipated by the wire is
P = I2 R = (2)2 (5) = 20 watts.
That's quite a bit of power for a piece of wire or a common resistor to dissipate.
The little round resistors with the color stripes that you see everywhere are
rated 1/4 watt, 1/2 watt, or 1 watt. One of those will pop if it tries to radiate
20 watts, and a piece of wire with 5-ohms will glow a nice hot bright red color.
Why to choose electronics engineering?
Alike electronics, software is a "logical" environment for such engineers, the job skills and sences to analyse an issue are basically the same. The market has benefits which are mostly not available on the electrical job market, and software jobs mostly go from one location, instead of being all over the place with electrical jobs.
Why use half wave rectification and what are its advantages over full wave rectification?
A full-wave rectifier will provide an output through both the positive and negative halves of the AC sine wave. The half-wave rectifier will only provide an output for half the cycle. The filtered outputs of both rectifiers can be "smoothed" well, but the higher the load on the half-wave rectifier, the more the output voltage will vary across a cycle of input power. This results in higher ripple and makes regulation a bit more difficult. The full-wave rectifier will provide an output through both the positive and negative halves of the sine wave. It effectively "inverts" the negative half of the cycle and provides two "pulses" of power per cycle as opposed to one pulse per cycle for the half-wave rectifier. The full-wave rectifier might use a pair of diodes and a center tapped transformer, or might use four diodes in a full wave bridge configuration and a transformer with no center tap.
Equation for resistance in a circuit?
Resistance is the opposition to the flow of electric current through a conductor. It is defined as the ratio of the potential difference (volts) between the ends of the conductor to the magnitude of the current (amps) through the conductor.
What are the uses of De-solder Guns?
De-soldering gun is used for removing molten solder, defective components, altering, and salvaging high value components in a circuit for possible re-use.
What are top ten core companies for training in electronics and telecommunication engineering?
There are following companies available in and around delhi for internship:-
-IDEA
-VODAFONE
-AIRTEL
-TATA COMMUNICATIONS
-UNINOR
-E-INFOCHIPS
-ISRO(IF YOU ARE TOPPER,THEN ONLY THEY WILL ALLOW)
-RELIANCE
-INTEL
you can choose any of the above based on your interest.
How to get internship:-
-Firstly, you need to obtain "No objection Certificate" from your college.
-Now visit the company, in which you are interested , submit your NOC and your latest resume there.
-Companies every year collect candidate's resume, and based on that they will short list some students based on their needs and allow them for internship.
-If you get shortlisted then they will call you and after that you can pursue training there.
-every year companies follow this procedure.
Hope, I have cleared your doubt.
for any other query , please post it here.
best of luck
regards.
Why capacitor does not allow DC?
In order for a capacitor to pass current, the voltage across it must be changing. In a DC circuit, the voltage does not change so, at equilibrium, the capacitor is effectively an open circuit.
We also call this DC blocking. You can take a signal with DC bias on it, perhaps because it came from a class A BJT amplifier, couple it with a capacitor, and the signal will make it through, but the DC bias will not.
How do electrical transformers work?
To do its magic on the high voltage and change it to low voltage the electrical transformer uses two rather intriguing and important phenomena. Firstly whenever an electric current flows, there is magnetism around it. Secondly whenever a magnetic field changes (by moving or by changing strength) a voltage is made. If there's a wire close by when this happens then a current will flow in the wire as the magnetism changes.
The electrical transformer takes in high voltage electricity and lets it run through lots of coils wound around an iron core. Because the current is alternating the magnetism in the core is also alternating. Also round the core is an output wire with less coils. The changing magnetism generates a current in the wire and less coils means less voltage. So the voltage is 'stepped-down'.
Answer#1...Wire produces a magnetic field when current is passed through it. If you wrap the wire around something (a core) to make a coil, it concentrates that field. The core isn't actually necessary but it helps concentrate the field and make the transformer more efficient.#2...If you pass a magnetic field through a wire, it produces electron flow.
If you make a coil with 100 wraps and pass current through it, it will produce the magnetic field. If you have another coil close enough to be IN that magnetic field, and it has 10 turns, you will get about 1/10 the voltage from the second coil that you put into the first one.
It gets a lot more complicated than that with formulas and all kinds of mathematics, but that is the basics of a "step down" transformer.
AnswerWhen an electron travels through a conductor it generates "ripples" in a fluid like medium (EMF) those ripples induce the electrons in conductors in close proximity to move(=current). In a transformer electrons in the input or primary side travel around the core perpendicularly causing the electrons in the core to spin(the core resembles a doughnut like shape) the secondary coil gets induced by the motion of electrons in the core. The a out put voltage is determine by the turns ration of the primary to secondary coils. In the mechanical world an electrical transformer is like a car transmission, converting torque (current) into speed(voltage) or vies versa. Total input power= Total output power.You cannot "convert" 9 amps in watts. Amps are a unit of electric current, and watts are a unit of electric power.
Power is given by
P = IV
where P is power, I is current and V is voltage. To determine the power (or wattage) you must know both the current and voltage.
Why is it necessary to modulate a signal onto a carrier wave?
There are two basic reason for modulation..... 1) It is extremely difficult to radiate low-frequncy signals from an antenna in the form of electromagnetic energy. 2)Information signals often occupy the same frequency band and if two or more sourses were transmitted at the same time they would interfere with each other.
One. Measure the load resistance. Divide by five. Use that as the added series resistance. (For 1000 ohm load, add 200 ohms in series.)
Note that this answer may be wrong for situations where the load resistance changes or the current is high, as you must consider source to load rejection ratio and power consumed by the added resistor.
Another way is to to get a stabilised plug top power unit . Open it up and use the electronic regulator from it. Wire your 6 volts DC in place of the transformer secondary and use output as normal. The integrated three terminal regulator you are looking for is called a 7805 industry standard 1 amp regulator.
ANSWER: Must know the load current first then add a series resistor to drop 1 volts with the current flow.
Why does the fuse blow when replaced?
Most likely a bad bulb, corroded socket or worn/shorted wires. Could be the brake switch too. I'd check in that order. If it ends up being a blown bulb, see sources and related links below for bulb information.
