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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
How do you do the PSP led light mod?
this will help you do exactly that just click this link: http://www.llamma.com/PSP/psp_led_lighted_trigger_buttons.htm or copy/paste to browser your welcome!!
Can you define the term Neutral in electrical terminology?
In a single phase system the neutral wire is the return path of the circuit and may be near ground potential, in multiphase systems it carries the unbalanced current.
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A neutral wire is always needed as the return path back to the power station for any single-phase circuit in which a single live wire feeds alternating current into the connected load.
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As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.
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It can be confusing. The NEC refers to "grounding" and "grounded" conductors (very different from each other) but not a neutral. The neutral is what the NEC calls a grounded conductor. This is NOT the same as the "grounding" conductor, which is the green or bare wire (US systems) providing a safety earth.
Before you do any work yourself,
on electrical circuits, equipment or appliances,
always use a test meter to ensure the circuit is, in fact, de-energized.
IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.
What is the difference between between FR and FRLS wire?
FR --> Fire Retardant
FRLS-->Fire Retardant low smoke
When ever wire gets fire Fr wire emit more smoke where as FRLS wire emits low smoke than the FR wires...
Explain the output wave form a circuit which has a zener diode in reverse biased?
A zener diode has a relatively constant reverse voltage, at the designated zener voltage. If you had a circuit, say, with an AC source, a resistor, and a zener, the waveform across the zener would be the AC source, clipped at the reverse bias zener voltage, and clipped again at the forward bias voltage, typically about 0.7 V.
Examples of the open loop control system?
1. The washing machine ;
2. Light regulator;
3. Vacum cleaner;
4. An old Microwave oven;
5. Water tap;
6. Electric Oven;
7. Electric fan;
True
The statement that current is equal to the vottage difference divided by the resistance is?
Ohm's law.
Can you bypass capacitor in line voltage?
Sure, depending on the type of circuit used, a cap may not be used at all. If you could provide some more detail as to the application, we could answer the question more accurately. In fact, a coil (or inductor) is more commonly used in 'line' voltages. It provides a 'stiffening' effect to help keep the line voltage at its desired value.
When did Michael Faraday invent electromagnetic?
Michael Faraday invented electromagnetic on 29TH of August 1831.
ADDED: He didn't "invent" it but discovered its principles.
What type of circuit is it that has a hot conductor contacting a neutral conductor?
A shorted circuit.
What is the difference between rated short circuit duration 3 seconds and 1 second circuit breaker?
The energy dissipated.
Where can you find manual for pincor generator made by Pioneer Gen-e-Motor Corp model RF-55HM5?
I have book for several models M-500S up to E-3500HDV Arthurford@charter.net
How does a garage door motor know which direction to operate in if the door is only closed halfway?
The circuitry "remembers" the previous direction and reverses that direction.
Is it possible to generate dc power. if yes please explain.?
Solar electric (photo-voltaic or PV) panels "generate" DC power when exposed to the sun.
For rotary type generation such as hydro, wind, diesel or steam turbine (fuelled by coal, natural gas or nuclear), the actual generator part of the system can generate AC or DC depnding on the generator installed for that application.
What is positive and negative dc voltage?
They are opposites of each other. This refers to the direction of the electrical current is flowing. A battery right side up has +4.6 volts across it. Current is flowing out of the top and I to the bottom. Flip it upside down, now measured the same way you'll see -4.6 volts, meaning current if flowing into the top and out of the bottom.
Additional AnswerThere is no such thing as a 'positive' and 'negative' voltage if you are referring to 'positive' and 'negative' in the sense of polarity or charge. Voltage is simply another name for potential difference, and you cannot have a positively- or negatively-charged potential difference! Presumably, what your question should ask is "What is positive and negative potential?".
The potential at any point in a circuit is measured with respect to another point in the same circuit -often, this is earth (or ground). For example, a car battery's negative terminal is usually earthed to the vehicle's metal chassis, so anything connected directly to its positive terminal has a potentialof +12 V.
On the other hand, 'positive' and 'negative' can also refer to sense or direction, rather than polarity or charge. Used in this sense, you can apply these terms to potential difference or voltage. For example, if a second battery acts in the same direction as another battery, then its voltage is acting in the positive sense (or direction); if it is connected to oppose another battery, then its voltage is acting in the negative sense. Applying the terms 'positive' and 'negative', in this sense, to potential differences or voltages, is useful in various electrical theorems, such as Kirchhoff's.
Can capacitor increase low voltage to high voltage?
yes a capacitor can improve voltage by improving power factor
Three phase power is almost never supplied to a residence. Power is supplied in two 240-volt lines, referenced to ground, which is also typically wired, giving you three overhead (or underground) lines for supply to a typical residence. A larger apartment building might use three-phase power.
AnswerSome countries do indeed supply residences with three-phase supplies instead of single phase. For example, the recently-constructed, two-bedroom, villa in which I live here is Cyprus has a three-phase service and this can be confirmed by examining the three-phase energy meter and the three-phase distribution panel. I don't really know why this should be the case, other than for the purpose of load sharing, as the villa's load is typical of residences elsewhere.
If the voltage is doubled the ampacity of a conductor is?
Unchanged.
The conductor's ampacity is affected by its composition (copper, aluminum, etc.), cross-sectional area, and temperature, not by the supply voltage.
The ampacity is limited because any conductor has resistance. When the conductor carries a load (supplies current), the conductor essentially becomes a resistance heater, and gets hot. At some point the temperature will become dangerous, either causing the conductor to melt or damaging the insulation or surrounding materials.
The voltage dropped across a conductor that is supplying current to a load is computed by the following formula:
E=I^2 X R
Or, voltage dropped equals current through the conductor squared times the resistance of the conductor.
Notice that the supply voltage is not even part of the equation.
All the mentioned parameters - composition, cross-sectional area, and temperature affect its resistance.
The ampacity of a conductor installed in a building can also be regulated by law, so, even though a conductor may pass a certain amount of current local laws may prohibit it's use anyway.
When a battery runs out does the battery voltage increase decrease or stay the same?
It should decrease
Can you ground an electrical system on an old two wire system without putting in new wire?
(LIFE SAFETY WARNING! [disclaimer]
Electricity is dangerous!
You can be injured or killed!
Improper installations can cause fire, injury and death!
Should you be doing this yourself?)
- It is not possible, per se, to "ground" an entire old two wire electrical system.
- It is possible, however - and allowed - to provide a ground at an individual receptacle by installing a grounding conductor according to strict limitations.
- Many simple devices are "double insulated" and designed to be used without any protective ground connection. But some are not so you have to be sure of the differences between them.
- It is recommended to install a new grounded circuit for point of use service wherever a protective ground connection is required.
- The best advice anyone should give here is to call a licensed electrician!
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The answers above are correct, you cannot ground a two wire system without running new wires, however, you can make your circuit as safe as a grounded one by using a GFCI. A GFCI does not have to be grounded to operate as it measures the current flow in both legs. It ensures the live current is equal in value (amperage) to the neutral current. In the case that the currents are not balanced, that is when you are in a hazardous situation.
In a grounded circuit, the fault current is supposed to flow to the ground, keeping you safe. The GFCI on the other hand will trip and give you as good if not better protection.
If you wish to use a GFCI receptacle to protect your circuit, you may install it at the first receptacle of your circuit and tie the remainder of the circuit to the load side of the GFCI so that it will protect the whole circuit. This is legal in Canada, I am not familiar with the American laws, but I would think it is acceptable there too. I do advise to hire a qualified electrical contractor, he should know the laws.
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Using a GFCI with no ground to the load connections is compliant with code in the US as well. The receptacles with the floating ground (protected by a GFCI) must be labeled "No Equipment Ground." However, not sure if local inspectors in all states and/or localities will accept this, especially in some big cities - e.g. New York, which have very strict wiring codes, so it's best to check with a local expert.
DO NOT connect the ground to the neutral! Unfortunately I have seen this done and it creates a very dangerous situation.
ALWAYS CHECK WITH YOUR LOCAL WIRING SAFETY OFFICE BEFORE YOU ATTEMPT TO CHANGE ANYTHING ON POWER MAINS OUTLETS
IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.
If you do this work yourself, always turn off the power
at the breaker box/fuse panel BEFORE you attempt to do any work
AND
always use an electricians test meter having metal-tipped probes
(not a simple proximity voltage indicator)
to insure the circuit is, in fact, de-energized.
