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Electrical Engineering
Electrical engineering is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism.
23,056 Questions
What is the difference between cut in and break down voltage?
what is the difference between cut- in and cut -out
How toremove starting motor on a 35o 4x4 ATV2oo4?
To remove the starting motor from a 2004 350 4x4 ATV, first disconnect the battery to ensure safety. Then, locate the starter motor, which is typically mounted on the side of the engine. Remove any bolts or screws securing it in place, disconnect the electrical connections, and gently pull the starter motor away from the engine. Make sure to keep track of all hardware for reinstallation.
How do you measure no-load current in a stabilizer?
Ohms law: I(Amps) = E(voltage) divided by R(resistance). In the case of coils (transformer), the resistance of the coil would simply be the total impedance (Z). If I am remembering this correctly, you get, I=E/(R+Z)
What will happen if you use AC voltage instead of DC voltage?
For some equipment it doesn't matter, other types of equipment will be destroyed.
For a simple electric heater or an incandescent bulb AC or DC are acceptable, provided the rms voltage of the AC is equal to the DC voltage. If the heater has a time switch, DC is unacceptable.
A DC motor may or may not work with AC depending on its type and size. The commutator motor as used in vacuum cleaners is essentially a DC motor, but most types of AC motor are not interchangeable to DC.
Electronic circuits usually required a DC supply and if AC is applied many of the components will be destroyed.
Can eddy current only exist in conductive or nonconductive materials?
'Eddy currents' are a circulating currents set up as a result of voltages induced into a metal component which not intended to carry current. For example, eddy currents are induced into the silicon-steel core of a transformer due to voltages induced into the core by the changing currents in the transformer's windings. Eddy currents are unavoidable, although steps can be taken to minimise them -in the case of a transformer's core, by manufacturing the core from laminations. Eddy currents generally have no useful function, but represent energy losses. To answer your question directly, eddy currents can only exist in conducting materials.
What are switching stations power cables and lines?
A switching station is used to switch high-voltage power into different routes (cables and lines) or, as loading changes during a day, into different transformers in the switching station. Also a switching station is needed to be able to isolate (switch off) a route for maintenance work that can't be done while the cables and lines are "hot".
In the power distribution industry the engineers talk about "cables" going underground or undersea and "lines", hung from big insulators, carried by big steel towers that go across the countryside.
In electrical engineering applications a "wire" is usually a relatively thin conductor, most often made of Copper and usually protected by insulation.
An electrical "power cable" usually contains more than one conductor. A typical power cable would have 3 "hot" Phase conductors and sometimes a Ground too.
An electrical "power line" is most often a single thick conductor having a steel "core" for strength. The core is wrapped in copper, or an alloy of it, for good conductivity. A power line is used to carry a single Phase or a Neutral, and is not usually covered in insulation.
In power distribution engineering a "power line" is never confused with a "power cable" as it helps to keep those technical terms distinct when describing a power distribution network.
The normal calculations for watts are as follows.
amps x volts = watts
volts2 / ohms = watts
amps2 x ohms = watts
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Scroll down to the Related links and look at "Watts, Volts, Amperes, and Ohms".
What is device used to convert temperature in to voltage?
temperature sensor
AnswerA thermo-voltaic junction, or thermo-voltaic pile, is used for this purpose. A thermo-voltaic junction consists of two dissimilar metals connected together; as the temperature increases, an increasing potential difference arises between the two metals. A thermo-voltaic 'pile' is a number of thermo-voltaic 'junctions' connected in series.
Why doesn't a shunt motor operate on a single phase AC supply?
Shunt motors do operate on single phase AC. There are millions, if not billions of them worldwide running right now.
Make certain your voltage supply is correct for your motor. Also, make certain you're providing the proper amperage. Make sure it's not a three phase motor. (three phase motors won't operate on single phase power.) If your supply voltage and amp supply is correct and the motor still doesn't run, you've got a bad motor.
The color code for a 4.34 kΩ resistor can be determined by first converting the resistance value into standard E12 series values. The closest value is 4.7 kΩ, but for 4.34 kΩ specifically, the color bands would be: Blue (4), Orange (3), and Red (multiplier of 100), followed by a tolerance band, typically Gold (±5%) or Silver (±10%). Therefore, the color bands would be Blue, Orange, Red, and Gold (or Silver).
Why you perform open circuit characteristics of a dc shunt generator?
to find the relation between emf generated and Field current .....
different measurement of temperature
How can you solve resistance to complicated circuits like diamond shaped circuits?
One way is to use Thevenin's theory and methods. Léon Charles Thévenin was a French telegraph engineer who extended Ohm's Law to the analysis of complex electrical circuits.
What replaces a EM48-23B-N transformer?
I suppose it depends on what you are repairing, I just replaced this exact transformer in a vintage Mr. Christmas Carousel Calliope. It is a 6v center tap transformer, I replaced mine with the one below which can be found on Amazon and is a 1amp. My carousel works good as new. I hope this helps someone.
Center-Tapped-Transformer-117VAC-12VAC/dp/B00SOY36M8
Inductors and capacitors are called reactive elements in electric circuits.these reactive elements also offer resistance in the circuit termed as reactance
for inductor it is wL (-j)
for capacitor i is 1/wC (j)
where L,C and w are inductance , capacitance and frequency of the AC source respectively
when clubbed with resistance the the resultant of the resistance and reactance gives us the impedance of a circuit
if the impeadence(R=0) of the circuit is of inductor only then these are called as purely inductive circuits
if the impedence of the circuit is dominated by inductor ( wL > 1/wC ) even though the circuit has resistance and capacitor then these circuits are called inductive circuits
What is a 4 channel amplifier?
A 4-channel amplifier is an audio amplification device designed to power four separate audio channels, typically used in car audio systems or home theaters. It allows for the connection of multiple speakers, enabling a more immersive sound experience by providing dedicated amplification for each channel. This configuration can support front, rear, or even subwoofer speakers, enhancing overall audio quality and clarity.
Why line to line 3 phase voltage 400V?
In a three-phase system, the line-to-line voltage is the voltage measured between any two of the three phases. For a standard three-phase system, the line-to-line voltage is related to the line-to-neutral voltage (phase voltage) by the equation: ( V_{LL} = \sqrt{3} \times V_{LN} ). In many industrial and commercial applications, a line-to-line voltage of 400V is common because it provides a balance of efficiency and power delivery suitable for heavy machinery and equipment. This standard voltage level is widely adopted in Europe and other regions for three-phase power distribution.
What happens if you change over too soon from star to delta?
The Star/Delta starter was probably the most commonly used reduced-voltage starter, but in a large number of applications, the performance achieved is less than ideal, and in some cases, the damage and interference is much worse than that caused by a Direct On Line starter.
Electronic motor-control systems, which offer soft-starts in DELTA configuration, are now replacing the use of manual or semi-automatic star-delta starters.
The Star/Delta starter requires a six terminal motor that is normally delta-connected direct to the 3-phase service lines. The Star Delta starter employs three contactors to initially start the motor in a star connection, then after a period of time, to reconnect the motor to the supply in a delta connection.
If there is insufficient torque available while connected in star, the motor can only accelerate to partial speed. When the timer operates (set normally from 5-10 seconds), the motor is disconnected from the supply and then reconnected in Delta resulting in full voltage start currents and torque.
The transition from star connection to delta connection requires that the current flow through the motor is interrupted. This is termed "Open Transition Switching" and with an induction motor operating at partial speed (or full load speed), there is a large current and torque transient produced at the point of reconnection. This transient is far worse than any produced by the DOL starter and can cause severe damage to equipment and the supply.
If there is insufficient torque produced by the motor in star, there is no way to accelerate the load to full speed without switching to delta and causing those severe current and torque transients. These must be allowed-for in the design of the motor and its starting system if they are to have an economic useful life.
Technical explanation
When the windings of a 3-phase motor are connected in STAR:
- the voltage applied to each winding is reduced to only (1 /.'/'3) [1 divided by root three] of the voltage applied to the winding when it is connected directly across two incoming power service line phases in DELTA.
- the current per winding is reduced to only (1 /.'/'3) [1 divided by root three] of the normal running current taken when it is connected in DELTA.
- so, because of the power law V [in volts] x I [in amps] = P [in watts],
the total output power when the motor is connected in STAR is:
PS = (1 /.'/'3 VL) x (1 /.'/'3 ID) = 1/3 [one third] PD
where VL is the phase line voltage
ID is the line current drawn in DELTA
PS is the total power the motor can produce when running in STAR
PD is the total power it can produce when running in DELTA.
- a further disadvantage when the motor is connected in STAR is that its total output torque is only 1/3 of the total torque it can produce when running in DELTA.
For more information please see the answers to the Related Questions shown below.
How the doubly fed induction generator build up voltage?
If a self-excited generator lost all its residual magnetism, can it build up an output voltage?
What is the purpose of voltage transformer?
A 'voltage transformer' (called a 'potential transformer' in North America) is classified as an 'instrument transformer', and is used to reduce the voltage of an electrical system to a lower, safe, level for the purposes of either operating a voltmeter or supplying a protection relay. At the same time, it electrically-isolates the meter or relay from the high-voltage system.
Which excitation synchronous motor drawn reactive power?
Hi,
Under excitation - inductive reactive power
Over excitation - Capacitive reactive power.
Why should the motor have a larger emf than generator?
A motor typically requires a larger electromotive force (emf) than a generator due to the need for overcoming various losses, such as resistance in the windings and friction in the mechanical components. Additionally, during operation, motors may demand higher starting currents to initiate motion, necessitating higher emf to ensure efficient performance. In contrast, generators convert mechanical energy to electrical energy, and their output emf is primarily determined by the mechanical input and load conditions rather than overcoming inherent losses.
