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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
What is the limitation of logic?
Logic has no limitations beyond that of the language used to communicate the idea. Logic cannot be used to prove things that are not true, but that is inherent in that to prove something it must be true. Pure logical reasoning has little application because there is not enough data to further it to any specific action. Abstract reasoning has infinite application.
Clarence Zener is a physicist from the United States who is credited with the invention of the Zener diode. He studied subjects like superconductivity and diffusion.
Foam resistance is a term that is commonly used in companies that create injection molds and fire resistant equipment. This term means that a product is able to resist damage or corrosion when it is in direct contact with chemicals or solvents.
Collector modulation is the amplitude modulation in which modulator varies the collector voltage of a transistor.
Not really. For years they have been using K band and Ka band. Yet fairly recently they have mostly phased out the use of K band. New Zealand is allowed to use the same three Ka band frequencies which are used in the USA. These Ka frequencies are 33.8, 34.7 and 35.5. The 34.7 Ka frequency is the easiest to detect with any quality radar detector. The 35.5 frequency is poorly detected by some radar detector brands, notably Cobra. The 33.8 Ka frequency may be only fairly well detected by dome radar detector brands.
If an inductor measures 75 ohms will it still be good?
Inductors are not categorized in ohms. Inductors are categorized by their inductance measured in henrys. This is a measurement that can be measured by using a special meter. The only thing that the resistance will tell you is that the coil in not open circuited. So there is no real way to know if it is still good.
What is an ultra wideband antenna?
Antennas can be tuned for specific frequencies to increase their gain. These types of antenna are sometimes referred to as narrowband. An ultra wideband antenna works for a lot of frequencies around what is called a center frequency. For example, if you had a narrowband antenna centered around 10 megahertz it might work for frequencies from 9 to 11 megahertz for example. If it were wide band it might go from 5 to 15 megahertz, and so forth. The bands are clustered around specific center frequencies for different applications.
What is a tuned rf jfet amplifier?
It's a junction gate field effect transistor that has it's bandwidth tuned to operate (amplify) in the radio frequency range.
Is biasing required when transistor work as switch?
Biasing might only be required for small signal switching below 1V. Small input signals might not always have enough voltage to cross the 0.7V B-E potential barrier. Then a slight offset voltage (biasing) must be used to bring the signal closer to the critical decision voltage of 0.7V across the B-E junction.
Note that I would refer to the B-E junction to be 0.7V rather than just the Base since it's not actually the Base that requires the 0.7V but it's the potential across the junction. Although the Base voltage is the same as the Base-Emitter voltage when the Emitter is connected to the ground, it's not always the case.
Biasing is not necessary for switching signals larger than 1V since the amplitude is enough even with Base resistor to raise the B-E junction potential from 0V to above 0.7V if correct value for base resistor is used.
It is however very important that a Base resistor Rb is provided to limit the current flowing from the input through the B-E junction to the ground. Transistors are best protected when the control is done with the correct current and not voltage, given that the correct voltages are applied. This resistor should be determined by the forward bias current gain (B) of the transistor, supply voltage, input switching signal voltage (Vin) and the load resistance RL.
Example: If one use a NPN transistor and connect the Emitter to the ground to switch a basic load via the collector. The load resistance (RL) = 100R, Supply voltage (Vs) = 10V, transistor forward bias current gain (B) = 100, and input switching voltage (Vin) = 5V, then the following method may be used
First consider:
Collector current:
Ic=(Vs - Vce)/RL
Base current:
Ib=(Ic*10)/(B) (The factor 10 is used for deviations in hfe value, it is a safety factor)
Vin-Vbe=Rb*Ib
Thus:
Rb= [B.RL.(Vin-Vbe)]/((Vs-Vce)*10)
Rb= [100.100.(5-0.7)]/((10-0.1)*10)
Rb= 434R
N.A.V.=470R
More about using transistor as a switch for DC supplies
Switching lights or relays on by using the Collector of a NPN is okay, but the method is not advised at all for more complex circuits. Beware of using the method to turn on other electronic systems or circuit boards. In this method the circuit will float at Vs when off, which can also damage other equipment dependant on them. It will also never be properly grounded when on. That may lead to erratic response in digital equipment or increased circuit noise in analog.
For turning on circuit boards or complex devices, the alternative in a NPN to turn the circuit on via its positive supply with the Emitter. This is not a good idea either since the 0.7V drop might cause supply voltage to be to low and increase line resistance. The supply voltages will drop and not be constant for changes in supply current.
Rather use PNP transistor, supply positive voltage to the Emitter and supply the load with the Collector. Pull the Base voltage low to create a 0.7 volt drop across the Base-Emitter junction. The calculations work almost the same as above except the Vin is now with reference to the Vs and not ground since we are pulling down. But this will ensure less resistance from the transistor when on and less volt drop, approximately 0.1V. Since the load is now controlled through it's positive supply. The load remains properly grounded for all conditions. But in this method one would have to pull the Base voltage low through a Base resistor aswell. To turn the device on a second NPN transistor is often used at it's Base to perform that function if conventional Vin=On and ground = Off input states are used. This method will result in a two transistor switch.
ANSWER: yes it is not required since the transistor must be forced to saturate to be used as a switch. However the current cannot be to the extent of adding a voltage forward drop to the transistor satureted comndition. as a rule a forced beta of ten is used
What are the three categories of materials used in electronics?
insulator, conductor and semiconductor
What is the definition of stability of radio receiver?
It is the ability of aradi receiver to deliver acostant amount of outpu during a given interval of time.
There can be one byte of data transferred at one time on the 8-bit data bus, but without knowing more about the architecture and the address and data bus multiplexing we cannot know how many bytes can be addressed.
Perhaps the machine architecture uses 2 address bus cycles to send out a 16-bit address and 6-bits of control signals, then uses 2 data bus cycles to read or write the 16-bit word at that address, which would mean this computer system addressed two bytes at one time.
Perhaps the machine architecture uses 3 address bus cycles to send out a 32-bit address and a 1-bit control signal, then uses 4 data bus cycles to read or write the 32-bit word at that address, which would mean this computer system addressed four bytes at one time.
Perhaps the machine architecture uses 6 address bus cycles to send out a 64-bit address and 2-bits of control signals, then uses 8 data bus cycles to read or write the 64-bit word at that address, which would mean this computer system addressed eight bytes at one time.
Perhaps the machine architecture has a variable word length (which could be specified in many different ways depending on the architecture), in which case almost any number of bytes could be addressed at one time (with different numbers of bytes in each addressing operation).
There are many other possibilities.
Is there any other current except AC and DC?
No. Alternating Current and Direct Current are the only two types of current.
You would use Amperes circuital law, which was discovered and named after Andre-Marie Ampere.
A: 31x4mv=124 mv +- 2mv
Is odd harmonics present in push pull amplifier?
Odd harmonics are theoretically the only harmonics that are produced by a push-pull amplifier, and even the level of odd harmonics should be very low.
What is the connection between a Siren and the ambulance siren?
Both are warnings of potential trouble.
What is 'mean filter' in digital image processing?
The Average (mean) filter smooths image data, thus eliminating noise. This filter performs spatial filtering on each individual pixel in an image using the grey level values in a square or rectangular window surrounding each pixel.
For example:
a1 a2 a3
a4 a5 a6 3x3 filter window
a7 a8 a9
The average filter computes the sum of all pixels in the filter window and then divides the sum by the number of pixels in the filter window:
Filtered pixel = (a1 + a2 + a3 + a4 ... + a9) / 9
Passwords for tamagotchi version 5?
Codes for the FamiTama, from the TamaDVD
On your FamiTama:
Activate the connect (heart) icon in the upper right corner.
Select DVD from the connect menu.
When prompted, enter one of the below passwords into your FamiTama.
Prize codes
13459 00080 ? from channel 4 character find game
05325 45130 ? from channel 5 soccer game
61063 66080 ? from channel 6 dance game
39194 70807 ? from channel 7 cookie cooking show
38186 70009 ? from channel 7 pizza cooking show
13854 00861 ? from channel 8 exercise game
Shopping TV (channel 9)
(These codes allow you to purchase goods at a reduced price.)
Goods from Japan
09010 03508 Oden 480G
03947 60120 Soba 320G
09000 43792 Takoyaki 200G
29137 38030 Dorayaki 160G
39824 90030 Senbei 280G
Goods from Asia/Oceania
90063 58010 Dumplings 360G
90073 79500 Mabodofu 400G
30080 90415 Soup 520G
32094 90533 Moon Cake 240G
03955 60653 Coconut Juice 280G
Goods from America
09110 43334 Hamburger 280G
39237 47030 Ice Cream 360G
03941 40751 Prime Rib 1240G
09100 13655 Hot Dog 360G
39925 98030 Chocolate 160G
Goods from Europe
90063 79051 Blueberry Creamcheese Bagel 200G
90073 50842 Sausages 240G
31081 90820 Shepherd's Pie 1160G
34099 90040 Pudding 120G
03955 60974 Chocolate Crepe 400G
Dougu (equipment)
09410 23964 Camp Fire 1200G
03947 00805 Textbook 1120G
09500 93141 Party Cracker 1200G
59632 02030 DVD 2000G
59529 63030 Aquarium 2800G
90063 45135 Stereo System 1600G
Omocha (toys)
90073 29055 Paints 800G
90073 80696 Train 1440G
69736 62030 Bubble Pipe 440G
03957 30636 Basketball Set 1200G
69325 24030 Magician's Hat 520G
35092 90961 Tennis Racket 1080G
09600 13661 Yo-yo 960G
09610 83726 Sandbox Toys 680G
Koukyuuhin (luxury items)
31185 90319 Repotchi DVD 5000G
The following fill 3 Hungry Hearts
07101 43297 shark fin (meal)
07101 43398 mushroom (meal)
The following fill 3 Happy Hearts
07600 43897 yacht (item)
07101 43196 Repotchi DVD (item)
07101 43499 gingerbread castle (snack)
07101 43590 pottery (rare)
07101 43691 cruise ship (rare)
The following increase Bonding level by 0.3%
07500 43694 Unchi-kun (item)
07500 43795 Gotchi King DVD (item)
07201 43894 magokorotchi (rare)
Note about Bonding Levels
The bonding level you see on the status screen is from 0% to 100% in steps of 10%. Internally, bonding is measured on a scale of 0 to 999 points. To see bonding go up by 10%, you need to use a 1-point item up to 100 times, or a 3-point item up to 34 times. This topic has more information about bonding: http://www.tamatalk.com/IB/index.php?showtopic=133696
The following can transformation certain characters into other characters
07200 43398 balance biscuit (meal)
07200 43499 milk (meal)
07400 43794 steamed bun (snack)
07400 43895 sesame pudding (snack)
07500 43896 dresser (item)
07900 43890 magnifying glass (item)
07900 43991 whistle (item)
07101 43095 mirror (item)
How do you access the color grid of a Sony KP-43HT20 rear projection television?
There are three color projection tubes in this puppy. Which one you gonna play with? All three have a control grid in them. One can't help but wonder why someone would want to do this.... To access the control grid of any cathode ray tube (and picture and projection tubes qualify), the set will have to be take apart to permit access to the internals. Note: if you are not at all familiar with electronics and what precautions are necessary when working around high voltage, leave this one alone! That said, a peek inside will reveal the three projection tubes in the back, and the easiest way to access a control grid would be to find the wiring harness and plug assembly that hooks up to the back of the projection tube to connect it to the circuitry that drives it (the circuit board). Now listen up. Information is provided here because someone wants it. The individuals who use the information without care and knowledge do so at their own risk. You can be injured or killed by connecting yourself to energized circuits. And the tubes run hot! You can be burned by them. Lastly, it is a know fact that individuals who are curious about stuff are gonna get the information they want however and where ever they can. It is provided here because it is firmly believed that, since the info is going to be gotten regardless, by getting it here, the curious person can be fully advised of the hazards possible in working on something like this. There is no good reason to fool around with the grid wiring (or any other wiring) on the projection tubes of a $1000 + Sony TV. If there is a problem with the set, it almost certainly isn't with the wires. It don't work dat way. Be smart about this one, Sparky. The life you save may be your own.
What are the Importance of transformers?
It is used when u need to step up or step down a particular voltage level.
Impedance inversion may be obtained with?
Impedance Inversion in Microwave circuits can be obtained by utilizing the Short Circuit or Open Circuit Transmission line of proper length.
If a wire with no current passes a magnetic field of flux will voltage be induced into the wire?
Yes, for as long as the magnetic field is moving along the conductor. A static magnetic field will not induce current, a dynamic field is required.
Ohms law states that
V = I * R
I = V/R
R = V/I
P = I*V
Where V = Voltage, I=Current, R = Resistance and P = Power or Watt Watt is the amount of electricity flowing through a line which is (Voltage times Current in (Amperage) = Power or watts) To find the power dissipated by a resistor of 1000 ohms, we first find the current I. The voltage is given as 200volts. Therefore I = V/R = 200/1000 = 0.2Amps We said Power or Watt = I*V Therefore the Power or watts dissipated by a resistor of 1000 ohms will be P=I*V = 200*0.2 = 40 Watts
