The energy tag has no wiki summary.
-2
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0answers
42 views
Best option for saving energy [closed]
Which is better option among sleep, hibernate and shutdown in terms of energy saving ?
And which is better in terms of computer's life ?
-3
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0answers
40 views
How long does my battery last? [closed]
The only information I'm given is that each battery has a useful energy of 100000 Wh (500 Wh/kg), my discharge rate is 10C, and has to power an electric motor that should output 1000 kW. I'm having ...
15
votes
1answer
428 views
Does this device which claims to reduce reactive energy from a house work?
I've opened a device that states that it can reduce the reactive energy from a house, by plugin it directly to the power outlet/wall socket. I think it is a con, so I've opened it and I saw this black ...
1
vote
0answers
61 views
How calculate three phase kilowatt hour from time sampled data of voltage and current of each phase
My problem is I want to calculate three phase kilo watt hour from time sampled data of current and voltages.
My doubts
1) How can I calculate the kilowatt hour from time sampled data? Is it any ...
3
votes
1answer
99 views
Kilowatt Hour Definition
This is a very simple question but something that I'm not able to wrap my head around. This Energy report states generated electricity. But what does "generated killowatthours" mean? I know that ...
1
vote
2answers
116 views
What happens to the circuit Voltage, Energy?
I was recently asked this question to calculate the voltage across a capacitor. The problem is described as follows :-
Consider a capacitor "C" connected across a voltage source "V". Once the ...
14
votes
6answers
573 views
Why is an inductor not a good antenna?
[An antenna must have] current flowing along its length, so that the resulting fields radiate that energy into space. (Receiving antennas are just this process in reverse).
[This] explains why ...
3
votes
2answers
176 views
Is the energy loss in a voltage drop equal to heat/mechanical work/light emitted?
I am wondering if the energy loss in a voltage drop over an entire circuit is equal to the energy transferred from the circuit (e.g. light/sound/mechanical energy/heat).
If this is true, wouldn't ...
0
votes
1answer
86 views
Does shutting down and repowering CPU consume more energy?
I have an internetshop that has 20 CPUs. Only 50% on average are being used throughout a regular day and almost 80-100% during saturdays. I use a Server-Client to Shutdown an unused computer but ...
34
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6answers
5k views
Does turning a lighbulb on and off repeatedly use more energy than just leaving it on for hours?
Let's say I have a 60W bulb in a lamp in my bedroom. If I kept the lamp on for 2 hours straight but the next day, I switched it on and off 10 times in intervals of 5 minutes. Which scenario would use ...
2
votes
1answer
234 views
Confusion between MW and MWh
A 1MW power plant producing power constantly for 24 hours will produce 24 MWh a day. Is that right?
If it is, I don't understand when it says, in ...
2
votes
2answers
163 views
How is energy consumed in a PN junction?
In the schematic above, there's a PN junction with a source \$V_d\$, the barrier potential \$V_J\$, contact potentials \$aV_{J0}\$ on the P-side and (1-a)\$V_{J0}\$ on the N-side. \$V_{J0}\$ ...
1
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4answers
103 views
Looking for a better understanding of a kilowatt hour and trying to size an electricity supplier using it
I am trying to design a fuel cell that can provide enough energy for 1 day's use a maximum capacity but I am having trouble sizing the fuel cell because I need a better understanding of kilowatt ...
3
votes
1answer
86 views
ARD00280 Microchip Energy Reference Schematic Live and Neutral Swapped?
Looking at the Microchip Energy Chip reference design
I noticed that the power is being sampled from neutral. My first reaction to this was this is backwards, that the power should be sampled from ...
1
vote
1answer
95 views
Power and energy measurment for embedded system -help needed
I am trying to measure the power consumption of a low power embedded system. As the embedded system consumes current in random pulses from the battery pack, I am using an oscilloscope to analyze the ...
-1
votes
1answer
229 views
Can we generate enough electricity to light up street lights by means of a dynamo being rotated by car wheels?
I often wonder if we can place an efficient dynamo underground on a fast moving highway (where traffic flow rarely stops). The dynamo is mechanically rotated and generate electricity to lightup the ...
4
votes
3answers
332 views
Electricity consumption of electrical machines - why do they consume electricity when they are not turned on?
The question is, why do electrical machines consume power when they are not turned on (they are plugged into an outlet)?
Also, suppose there is a seven-port USB hub with AC power. Is the power ...
3
votes
3answers
175 views
Energy conversion from Electrical to Mechanical
I have a requirement where I have to design a very small device capable of pulling in and out a small piston through a feedback.I know it can be done using motor but AFAIK I need higher voltage and ...
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1answer
56 views
Subject Selection [closed]
'Utilizing Electrical Energy' or 'Protective Relay' which subject should I choose in my 5th Sem in Electrical and Electronic Engineering. Help me giving me advice on this topic.
13
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1answer
3k views
I need the most basic circuit diagram for wireless energy transfer please
I have been all over the net looking for the most basic circuit diagram or instructions to put together a small project on wireless energy transfer. If anyone knows of a good schematic that is super ...
7
votes
2answers
2k views
Is it possible to use Kinetic energy to power small devices?
I've tried looking around for as much information as I could gather to build really small wearable electronics that could power themselves by generating energy with movement.
I know that the ...
3
votes
1answer
148 views
What is the energy efficiency between FM radio tower broadcasting over an area vs point to point streaming via Internet?
Doing some research, it seems that an FM radio tower in a densely popoulated area can maximally transmit about 50kW of power. If you assume a certain amount of people tuning into the station, is that ...
4
votes
2answers
1k views
How to compare mAh and Wh
When looking at consumer electronic devices with batteries I sometimes see the battery capacity listed in Wh (watt hours) and sometimes in mAh (milliamp hours). I would like to be able to compare the ...
2
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2answers
210 views
How efficient are micro turbines in generating efficent energy? [closed]
Would one large wind turbine be more efficient than many small wind turbines in theory?
5
votes
5answers
505 views
Cheapest way to dissipate energy (discharge battery)
What is the cheapest way to burn a lot of energy? Say I want to burn 800W (4V, 200A). How should I do that?
Ugly suggestions like: use a pot of water and a cable are welcome :)
It should be easy and ...
2
votes
3answers
372 views
Line, Neutral and Ground and another Ground
I try to make a 110VAC energy meter connected to my computer out of the CS5490
This IC measures voltage and current over a voltage divider and shunt resistor respectively and then calculates the ...
2
votes
1answer
152 views
Schneider EGX100 Gateway with AB PLC 5 series
I was investigating hooking up Modbus devices to an AllenBradley PLC 5/40E using a Schneider Electric EGX100 Ethernet gateway.
I can access the web server on the gateway device and monitor the slave ...
1
vote
1answer
569 views
Parallel Operation Problems
I need information about how to set a load sharing devices (woodward brand 2301 A), because when it's working parallel is always take over the load to high and caused reverse power protection active, ...
2
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2answers
135 views
Express bytes over cat5e as energy?
I'm interested in this purely from personal interest, I'm not a student.
Can I express 1024 bytes of information travelling over cat5e as joules (or some measure that fits into energy of e=mc^2 )? ...
2
votes
1answer
330 views
Difference between indoor and outdoor PV panels
I am building an energy harvesting sensor for building installation, and I have to choose between two panels:
Indoor, 5V, 47uA Isc @ 200 Lx
Outdoor, 6V, 15.9mA Isc @ 50 kLx (note the different light ...
4
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2answers
352 views
High voltages vs. Energy loss
How does high voltages of electricity coming from power plants also helps in saving energy?
0
votes
1answer
288 views
How could a charger “cut out” when charging is complete? [duplicate]
Possible Duplicate:
Why is it so problematic to have close to zero standby power consumption?
How would you detect vampire/standby power?
This article discusses why cell phone users have ...
3
votes
3answers
138 views
A few questions regarding B/E-fields in practical circuitry
I have been trying a few learning resources to help unlearn some of the notions that electrons flow through as energy.
Chiefly this resource is what I have used:
Amasci - IN A SIMPLE CIRCUIT, WHERE ...
12
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3answers
4k views
Why are deep cycle batteries rated in amp hours instead of watts hours?
Why are deep cycle batteries rated in amp-hours instead of watt-hours? For example if I see a 85Ah battery, I multiply 85Ah x 12V to get 1020 watts. As household electricity use is measured in watt ...
0
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1answer
76 views
flexible and cheap solar cells? howto transform the energy?
I would like to charge my iphone through solar energy, but i need to know a couple of things:
. What should I do to convert the solar energy into energy delivered through the usb?
. Where can I fine ...
1
vote
2answers
116 views
How and where is energy dissipated in a driven traction motor?
When a fully loaded elevator is moving down its potential energy is decreased and I guess is somehow converted by the elevator traction motor into heat.
How exactly does it happen? What exact ...
2
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1answer
2k views
Whole current meter
I need information on the major difference between an WHOLE CURRENT energy meter and a KWH energy meter, if there is.Any link or resource information would be of great help.
Thanks
2
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1answer
220 views
How is Switching between standard electricity and solar/other electricity achieved?
I'm contemplating various ways of using renewable energy, but I'm also interested in learning more about the subject. At the moment I'm trying to understand a few aspects:
1. How to measure and track ...
5
votes
4answers
355 views
Solar cells & Batteries
I was planning on having a couple of solar cells recharging a battery!
My question for this is:
How can I recharge a battery through solar cells and at the same time let the battery do some ...
3
votes
7answers
289 views
Effects of Pulsed vs Direct Current on Battery Depletion
I'm doing some work with a portable, cell-battery-based electronics and someone on the design team mentioned that pulsed current will more quickly deplete a battery than constant current, even if both ...
2
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4answers
337 views
Alternator with torque proportional to angular velocity
Im interested in buying or designing an alternator/electrical generator that increases torque as rpms increase - is there an alternator design that increases resistance as rpm/angular velocity ...
5
votes
4answers
201 views
Measuring total energy used by a project
Is there a cheap/simple way I can empirically measure the total energy used by my project over a sample time of several minutes?
It's a microcontroller based system which repeatedly wakes up, does ...
3
votes
3answers
199 views
Temperature vs AC energy consumption
I'm working on a project about electricity pricing, and need to understand the following: to keep the room at confortable temperature (70 degree, for example), does the amount of energy consumed by ...
5
votes
5answers
842 views
Is it possible to quantify electric power consumption on a fuse?
If you have a common fuse is there way quantify the power consumption which is flowing through this fuse. Or could you replace the fuse with something that measures the power consumption but still ...
15
votes
5answers
728 views
Why is it so problematic to have close to zero standby power consumption?
Each electronic device consumes electric power when it is "idle" unless it has a mechanical switch. I can understand that for example a TV with a remote control needs to "be ready" to receive a ...
36
votes
2answers
3k views
Lightning bolt vs. batteries: a coulomb in everyday terms
I am trying to decide if the information on the wikipedia page
http://en.wikipedia.org/wiki/Coulomb#In_everyday_terms
is reasonable. In particular the statements that a lightning bolt has about 15 ...
5
votes
2answers
544 views
Maximum power out of a piezo?
How do you extract the maximum amount of energy from a piezoelectric element? (For energy harvesting purposes.)
The maximum power theorem would seem to say that you need to load it with a ...
5
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5answers
1k views
how do energy consumption (Ah, kWh) meters work?
How do devices which measure energy consumed work? For example the ones in solar regulators/chargers which display how many Ah went into the battery and how many went out?
Do they just measure the ...
11
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2answers
2k views
What's the highest theoretical energy density for a chemical battery?
This is more a physics/chemistry/nanotech question, but what's the theoretical best energy density you could get out of a chemical battery (or fuel cell), if you could arrange atoms in any manner you ...
6
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4answers
227 views
Alternative Energy Storage
Can anyone suggest an alternative to energy from a battery?
I'd like a system to replace my deep cycle leisure battery, I currently use this 110 AH leisure battery with a 1200W inverter.
I run my ...
