What are the necessity of embedded systems?
An embedded system is a special-purpose computer system designed to perform one or a few dedicated functions,[1] often with real-time computing constraints. It is usually embedded as part of a complete device including hardware and mechanical parts. In contrast, a general-purpose computer, such as a personal computer, can do many different tasks depending on programming. Embedded systems control many of the common devices in use today.
Since the embedded system is dedicated to specific tasks, design engineers can optimize it, reducing the size and cost of the product, or increasing the reliability and performance. Some embedded systems are mass-produced, benefiting from economies of scale.
Physically, embedded systems range from portable devices such as digital watches and MP4 players, to large stationary installations like traffic lights, factory controllers, or the systems controlling nuclear power plants. Complexity varies from low, with a single micro controller chip, to very high with multiple units, peripherals and networks mounted inside a large chassis or enclosure.
In general, "embedded system" is not an exactly defined term, as many systems have some element of programmability. For example, Handheld computers share some elements with embedded systems - such as the operating systems and microprocessors which power them - but are not truly embedded systems, because they allow different applications to be loaded and peripherals to be connected.
A Cathode Ray Tube (CRT) is found in a Computer Monitor and is the most expensive part. Within the CRT are three electron guns, Red, Green and Blue. Each of these guns streams a steady flow of electrons left to right for each line of your monitor. As the electrons hit the phosphors on the CRT, the phosphor will glow certain intensities. As a new line begins the guns will then begin at the left and continue right, these guns will repeat this process sometimes thousands of time until the screen has been completely drawn line by line. Once the phosphors on the CRT have been hit with an electron they will only glow for a short period of time, because of this the CRT must be refreshed which means the process will be repeated.
What device can be used to increase current in a DC circuit?
Transformer or instrument transformer. It can increase and decrease current output.
Why emitter follower preferred to transforms as a impedance matching?
because it has high input impedance and low output impedance
Is Light Emitting Diode conduct in both direction?
A light emitting diode does not conduct in both directions.
The basic explanation for the ripple effect is that a sing event causes a number of knock on effects and consequences far beyond the location of the initial event. An example of this might be a tsunami caused by an earthquake under the ocean.
What is the correct calculation for voltage if the resistance is 3 ohms and the current is 4 amps?
What you are talking about is the electrical potential, or voltage, necessary to produce a current of 4 amps through a material with a resistance of 3 ohms. The typical way to solve such a problem is by using Ohm's Law, stating that the current produced is proportional to the potential across the resistor but inversely proportional to the resistance. In other words, I = V / R, where I is the current in amps, V is the electrical potential in volts, and R is the resistance in ohms. Here we know R and I, so we rearrange this equation to get V by itself: V = I * R. So, to get the answer, multiply your 4-amp current by your 3-ohm resistance, and you will get 12 volts.
How do electrical charges flow in a series circuit?
The eletrical current goes out of the positive end to the first load and uses a fraction of its power in the first load then continues to the second load and it does the same as the first load and then it either goes to the negative end or goes in more loads until it reaches the negative end.
What year did the first Circuit City open ?
The first Circuit City store opened in 1949. Founded by Samuel S. Wurtzel, it initially started as a small television store in Richmond, Virginia. Over the years, it expanded into a major electronics retailer in the United States.
Why using electrolytic capacitor for dc voltage?
Electrolytic Capacitors can only be used with DC supplies because they cannot cope with AC; they are polarised and AC will cause them to blow, whether that's internal or external; in which case you've some cleaning-up to do!
About 24 volts. Take 18 and divide by 0.707, then subtract about 1.4 to compensate for the two diodes that will always be in series with the load.
Of course, any load will cause ripple, so the 24 volts is with nearly no load.
Does mAh matter when replacing a battery?
mAh is a measure of the amount of charge stored in a cell or battery (set of cells). One (1) Ah is the equivalent of 1000mAh, and so the statement can be made that a cell with 2000mAh of stored charge can supply a device drawing one (1) mA for 2000 hours -- before needing replacement or recharge.
It also means 1/1000*C/s*3600s.(1 milli= 1/1000, C=Unit for charge, s=seconds) which finally means that a battery rated 1mAh can hold a charge equal to 3.6 coulombs of charge.
What would be a parallel circuit in your house?
== == A Parallel circuit is one where the current flows in several circuits (or 'branches') at the same time.
In the house, the Main Breaker box (or fuse panel) is connected to the city's power lines. The current flows through the main circuit breaker and is then split into 2 or more circuits each of which is protected by its own circuit breaker.
Envision a water pipe that is mounted horizontally in the attic. The pipe has 10 one inch holes cut into it, into these holes are fitted 10 one inch pipes that let water flow through each one as required (such as when the toilet is flushed, or the kitchen sink faucet is turned on).
So, coming out of the Main Breaker box are several cables (each protected by its own smaller breaker), each going to a separate room, or area (outdoor patio, or detached garage).
The reason for parallel electrical circuits is to limit the amount of current in each cable. If there was only one cable for the entire house, all of the current for every electrical device in the house would have to flow through the same cable, as opposed to each room (or area) having its own cable and only using as much current as is required for that room.
I hope this helps, if so, please 'Recommend Contributor', and reply to this answer for more info, or a more detailed explanation.
Why the pins in the three pin plug are split up to the middle?
In the UK, we use three pin plugs. Neutral (blue cable), Positive (brown cable), Earth (green and yellow striped cable). Positive is also known as the Live cable. The Earth cable is an important safety feature that directs electricity safely to earth should a short-circuit cause the device's metal body (a toaster, for instance) to become live and a dangerous shock is possible to any one touching the device's metal body. Before the modern standard colouring was introduced, black was the neutral, red the positive, and green the earth. This old colouring can still be found in buildings built before the change-over.
What are the disadvantages of a three phase induction motor?
The primary disadvantage of the three phase induction motor is that speed control is a challenge. But new technology in the form of VFDs (variable speed drives) is now rectifying this situation very effectively. Another disadvantage is that single phase power is common while three phase power is less commonly available.
Who is the inventor of a dynamo?
Zenobe Gramme, a Belgian inventor exhibited an industrial scale dynamo at the Academy of Sciences in Paris in 1971.
An AND circuit is a circuit that takes two or more inputs, and generates an output that is the boolean AND function of those inputs. Two light switches in series, for instance, is an AND circuit because both switches have to be on for the light to be on. If the switches were wired in parallel to each other, and then in series with the light, that would be an OR circuit.
resistance is useful when a plane is flying in the air, air resistance. it is also useful when a boat is floating on water, water resistance.
a close approximation of the forward current is an exponential function of voltage, but it has constants that must be empirically adjusted for accuracy. the reverse breakdown is a bit tricker to model accurately.
The function look something like this: I = K1 eK2(V-K3)
When measuring voltage drop across a switch what is the maximum allowable voltage drop?
The voltage drop should be as close to zero as would be readable by a typical volt meter. If it is measurable you likely have a problem with corrosion or oxidation in switch that is increasing resistance. If you can measure a voltage drop across a closed switch contact, replace the switch.
Or the switch is open, try flipping the switch!
What is effect of noise on digital communication system?
it will affect the output of a receiver only if it falls within the passband.in that case,the carrier and noise voltage will mix and the difference frequency,if audible,will interfere with the reception of the wanted signal..
Why you use capacitor with voltage regulator ic 7805?
in ic 7805 their is two capacitor is used one of them is used for the settling/transient time and another is used to provide inductive effect....
What would happen if the resistance in a circuit remained the same and the voltage decreased?
A well designed circuit should be able to operate over a range of voltages, not just at one voltage. Especially a circuit which is intended to be powered by a battery. As the battery starts to get used up, and the voltage drops, you want the circuit to operate as planned.