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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 are regulators and what do they do?
The voltage regulator may be on the back of your alternator ( or on older vehicles
the voltage regulator was separate / external )
Why we use oscillator to convert DC into AC?
An oscillator is capable to oscillate an output about a mean with certain predetermined frequency. The AC being a periodically oscillating can thus be generated using an oscillator with fixing the amplitude of the signal preferably using a multiplier (with a steady value) or an amplifier. This feature is typically helpful for eg. in control systems in drives.
There are of course other ways to produce AC from DC quantities too.
What is Magnitude of the voltage or current?
"Magnitude" means how strong it is - how much voltage (how many volts), or how much current (how many amperes).
What happens to resistance when resistors are wired in parallel delta circuit?
What do you mean by a 'parallel delta' circuit -is there such a connection.
When an inverter is placed between both inputs of an S-R flip-flop the resulting flip-flop is?
D flip-flop
How to calculate the current gain in darlington pair?
start at Ic'= Ic1+Ic2 Ib'=Ib1 Ic1=B1*Ib' Ie1=Ib2=Ib'(B1+1)=Ib'B1 + Ib'
Ic' = Ib'*B1 + Ic2
Ic2= B2(Ib'B1+Ib')
Ic' = Ib'B1 + Ib'B1B2 + Ib'B2
divide by Ib'
Ic'/Ib'= current gain =B'=B1+B2+B1B2
note: calculations without resistance
What material would you use as protective barrier to shield against impact?
Reinforced Concrete works well against vehicle impact and bomb detonation. To solve for the applied force on the barrier, calculate the amount of energy required for the shield to absorb. Typically impact loads are twice the calculated static loads. So if it's a 1000lbs car... the barrier should be designed for 2000lbs applied at the height of the bumper.
Does current flow through a resistor or across a resistor?
Normally through the resistor's internal construction. It flows through any part of the resistor that has low resistance- be it anywere. And then there's this. It might be that one should consider that current flows through a resistor and voltage is dropped across a resistor. Perhaps this is where the question began. The former is fairly straight forward. The latter can be vexing. Voltage is said to be dropped across a resistor when current is flowing through it. The voltage drop may be also considered as the voltage measureable across that resistor or the voltage "felt" by that resistor. It's as if that resistor was in a circuit by itself and hooked up to a battery of that equivalent voltage.
A UM66 is an IC or integrated circuit that generates a pleasing music sound. It works on a supply voltage of 3 volts.
The UM66 is an electronic doorbell. It requires a botton for the door, a single transistor, a battery and a speaker.
Measurements and instrumentation - functional elements of an instrument?
sensors,signal processor and data representation
How would you setup an auto-ranging multimeter to measure 120 VAC?
If it is auto-ranging, there is no set-up - that's what auto-ranging means.
Who made the remote-controlled steamroller?
There doesn't seem to be a record of the first remote-controlled (RC) steamroller. Since the dawn of the electronics age, schemes have been devised to apply RC technology to "drive" different devices and, later, equipments. There are obvious advantages to operating something remotely. The newer RC units take advantage of digital technology to provide sophisticated control possibilities. It is unclear who first adapted RC technology to a steamroller.
How can you open a pressure cooker which was made in Italy?
Most contemporary pressure cookers demand that the user "twist" the top to open it. One will need to push the two handles "apart" to disengage the locking flanges built into the lid and the rim of the pot. If the unit hasn't been opened in a while, the rubber gasket may cause the top to stick. Some "coaxing" may be required to separate the two pieces. Usually most units work by turning the top counterclockwise (looking down on the unit) to get the thing open. Be sure to check the gasket for cracks and tears before each use. Failure of the gasket can make a mess in the kitchen - and that's if it doesn't burn anyone by throwing very hot food and steam or superheated water on them. Good luck with this one.
Fundamental principle of current transducer?
The basic principle of current transformer is same as that of the power transformer. Like the power transformer current transformer also contains a primary and a secondary winding. Whenever an alternating current flows through the primary winding alternating magnetic flux is produced, which then induces alternating current in the secondary winding. In case of current transformers the load impedance or "burden" is very small. Therefore the current transformer operates under short circuit conditions. Also the current in the secondary winding does not depend load impedance but depends on the current flowing in the primary winding.
How does copper conduct electricity?
Copper conducts electricity by "musical electrons" like other conductors do. Let's look at copper and see what's up. Copper atoms in a copper wire all form some kind of metallic crystal structure. Not all the electrons in the valence shells of the copper atoms are "locked in place" in this structure. They are free to move around, and are said to be "free electrons" in this application. As they are not "bound" in the structure, the electrons can be made to move fairly easily. They can contribute to current flow. If we apply a voltage across the wire from end to end, electrons will enter one end of the wire and electrons will emerge from the other. Not the same electrons, mind you. Put some in one end, some come out the other. It could also be said that some of the electrons of the copper are at Fermi energy levels that are in what is said to be the "conduction band" for copper. The conduction band is the minimum energy level necessary for electrons of a given material to be in to support conduction in that material. If the Fermi energy levels of the valence band electrons is up in the conduction band, then that material is a conductor. Copper is this way.
Total opposition to current flow in an AC circuit with both resistance and reactance is called?
Impedance.
The property of one coil due to which it oposses the change of current in the other coil is called mutual inductance b\w two coil.
It will still be 4.5V except your meter will either indicate "-" for negative or normally no indication at all for positive. If your meter indicates both negative and positive, you will see "+".
Air resistance depends on what?
The amount of air resistance an object has depends on it's shape and it's frontal cross-section.
What is the difference between phase angle and phase difference?
Although we use the term 'Phase angle' it's also an angle referred to another phasor (voltage or current).
For example,
conventionally when expressing power factor, we use 'voltage' as the reference. So the 'phase angle' of a particular phasor is the phase difference between our reference (voltage) & the phasor.
As the gist, both mean the same except that 'phase angle' is the direction of the phasor w.r.t. positive x direction (reference)..
AnswerBy definition, phase angle is the angle by which a load current leads or lags a supply voltage.
Phase difference is the angle between any two electical quantities -for example, the angle two phase voltages of a three-phase system.
Why we use patch antenna in communication?
because patch antenna are used in order to achieve higher gain small dimensions, light weight, slim size and easy manufacturing as compared with parabolic dish or other antenna's
What is the role of a diode in an am radio?
Whenever a signal with components at several different frequencies flows through a diode,
the diode causes "mixing" among the frequencies ... for every pair of frequencies in the original
signal, two new frequency components are created: one at the sum of the original two, and one
at their difference. That is, if the original signal's wave has frequencies 'A' and 'B' in it, and it's
passed through a diode, then the output wave will have four frequencies in it: A, B, A+B, and A-B.
The original signal that enters an AM radio is the one that comes down from the antenna. If it's
an AM radio signal, then it consists of three frequencies: Carrier, Carrier+music, and Carrier-music.
There are 3 pairs of frequencies in this set. For each pair, the diode creates new signal components,
at the sum and difference of the original 2 frequencies. So with 3 different frequencies before the
diode, we have all of the following frequencies coming out after the diode:
1). Carrier
2). Carrier+music
3). (Carrier) + (Carrier+music)
4). (Carrier) - (Carrier+music)
5). Carrier
6). Carrier-music
7). (Carrier) + (Carrier-music)
8). (Carrier) - (Carrier-music)
9). Carrier+music
10). Carrier-music
11). (Carrier+music) + (Carrier-music)
12). (Carrier+music) - (Carrier-music)
To see what we've got now, let's go through the list and simplify the expressions:
1). Carrier
2). Carrier+music
3). 2xCarrier + music
4). -music
5). Carrier
6). Carrier-music
7). 2 x Carrier - music
8). music
9). Carrier+music
10). Carrier-music
11). 2 x Carrier
12). 2 x music
Looking through the list, we see that 9 of the 12 products are up around the frequency of the
radio carrier. It's easy to filter them out and throw them away, leaving only the following
three component signal frequencies, in the audio range:
4). -music
8). music
12). 2 x music
Mathematically, positive and negative frequencies are the same signal, so components #4 and #8
can be added to produce a component with double the amplitude (volume) of either one, which
only leaves the component at double the frequency of the music. It's in the range of legitimate
music frequencies, so we can't get rid of it completely. But it's weak to begin with, when it comes
out of the diode, and it's competing with the double-amplitude component at the real-music-frequency,
so it doesn't trash the desired signal too severely. What we're left with is the components
equal to the frequencies in the original music program, with some unavoidable distortion
on account of the presence of the low-level second harmonic.
The purpose of the diode was to perform the mixing of frequencies, so that we could separate
them by filtering, discard the ones that were used only to transport the music to us through
space, and keep the ones we want to send to the speaker or earphones.
