Energy is defined as the amount of work that can be performed by force, measured in Joules. Energy is Power over Time. This is a poor tag to use. Please consider if your question relates to Energy as defined in physics, not as a synonym for Power or capacity.

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3
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2answers
84 views

How do I design a current transformer?

I want to make a Current transformer using toroidal ferrites to measure 220/50-60Hz AC current(40A max). Is it possible? And how can I calculate secondary turns count? Ferrite properties: H = 2000, ...
0
votes
1answer
84 views

Can an electron carry only one charge?

Sorry if this has been asked before. Could also be a really basic question (new to electrical study). I am a bit confused about the relationship between electrons and charges. So what I understand is ...
0
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1answer
39 views

How to use a graph of a wavefunction (psi) to create an approximate graph for potential (U)?

I don't understand how the top graph was used to approximate the bottom graph, could someone please explain to me what was going on? I know that in regions 1, 3, 5, 7, there is no oscillation and ...
0
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1answer
67 views

Why monitoring power and energy in energy usage meters?

This time my question about the how power companies monitor usage. We get electric usage bill in [Kilo watt hour]/Energy. What should be looked up on for monitoring the usage the instantaneous energy ...
2
votes
1answer
74 views

Can I extrapolate the rated overload spec of a wirewound resistor to a joule rating?

I'm considering using a Vishay FVT series resistor for precharging some capacitors. Capacitance: 3300uF Voltage: 730V Resistance: 500 ohms Resistor continuous wattage: 25W This series, like many ...
0
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1answer
47 views

Energy state of transistors

Are there any energy states of transistors? i.e. zero energy, high energy etc. If that is possible, can't we employ the configurations of transistors such as storing memory as energy sources? That ...
1
vote
1answer
82 views

How big should battery be to power two strips of led for few hours?

I have an idea for halloween costume for upcoming Halloween. It will involve building two small sets of infinity mirrors. I am completely new to the electrical engineering. The infinity mirrors ...
0
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2answers
105 views

Electrical energy in a fighter aircraft

A car uses a car battery and an alternator powered by the engine. But where does the electrical energy for fighter aircraft comes from to maintain the onboard systems? And which voltage and frequency ...
2
votes
1answer
122 views

Harvesting Back EMF Possible?

Let me start by saying that I am not talking about the free energy or "overunity" idea of back EMF. When searching around for information I can only seem to find information from free energy sites, ...
1
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2answers
79 views

Energy direction in an electronic circuit

I've been reading a number of materials trying to understand the physics that allow electricity to be possible. I'm confused by this virtual positive [charged] particle (often called a test particle) ...
0
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2answers
90 views

Solar panel calculation

I have a small solar panel of the following, Area = 0.0078 square meter Rated Power = 1 W Now, I am interested to calculated the total energy this solar panel can harvest over a day. I am taking ...
1
vote
1answer
51 views

How to monitor produced energy?

I want to monitor energy produced by 250W solar panel. But I need some hints. Does anyone knows something? Is it possible using ACS758 chip or better I have to use current transformator? Finally I ...
2
votes
1answer
535 views

Theory behind the “Joule Ringer” circuit

The less-than-critical thinking free energy types are pointing to the "Super Joule Ringer" demonstrations online, where a quick touch with a 9 V battery illuminates an LED for hours. ...
2
votes
2answers
166 views

Charging capacitors in parallel with a battery

I am trying to figure out a system to charge a series capacitor bank without too much current going through the capacitors. I had the idea of putting a battery in parallel with the series capacitor ...
0
votes
0answers
86 views

Can't find Broadcom BCM4329 datasheet

I need to find information about my phone energy consumption and I can't find a proper datasheet about the BCM4329 chipset. Does someone have it? I'd like to create a power profile for PowerTutor in ...
0
votes
2answers
137 views

How to understand the “basics” of electricity? [closed]

I want to be a self-taught computer engineer ... massive goal, but it's what I want eventually. I check out textbooks and online resources, but I feel like I need a prerequisite somewhat -- I still ...
0
votes
4answers
131 views

Calculation of PV daily energy yield

How can you calculate how much energy a PV panel (known size and wattage) produces in a day given the exact insolation in kWh/m2/day?
0
votes
1answer
81 views

Can I connect my Philips sound system to my Samsung tablet? [closed]

I have a Philips SPA 4310/10 Sound System and I want to connect via 3.5mm jack to my 10" Samsung Galaxy Tab 3 P5200 to listen some music. Am I at risk of short-circuiting the tablet? Or will ...
0
votes
3answers
111 views

Why harvesting energy why not harvesting power?

I am wondering why is it called Harvesting energy and why not harvesting power? Energy is measured in Joules/s and power is Watt but the result is watt. For example if we harvest energy from sun or ...
0
votes
2answers
108 views

Tippmatic auto shut-off switch - how to use it?

Some products in my company are now required to use an auto shut-off switch to be compliant with new regulations in European space (European Eco-Design Directive ErP). I got word that the device ...
1
vote
2answers
99 views

A good way to storage/precharge energy for short bursts of consumption?

I have a battery powered application that must occasionally use a servo motor (like the ones in model airplanes, e.g. Turnigy TR-1160A). This servo will be used in short bursts of 1~2 seconds at a ...
1
vote
2answers
109 views

Four quadrant description

I am developing applications for energy automation for power generation and distribution utilities but i dont have much electrical engineering background. I always have confusion when it comes to ...
-2
votes
1answer
55 views

The bandwidth Ω of a low-pass signal f(t) ↔ F(ω)

I'm not sure about the answers to the two parts of this question: The bandwidth Ω of a low-pass signal f(t) ↔ F(ω) is defined by the constraint: $$ \frac{1}{2\pi } \int_{- \Omega }^{\Omega } ...
0
votes
1answer
80 views

How does the principle of conservation of energy for a phase-shifter transformer apply?

Since the phase shifter transformer is used for regulating the real power in the transmission line by means of changing the angle it leads to the fact that the real power at the secondary side ...
1
vote
0answers
38 views

What happens to the energy bands when a forward bias > Buit-in potential is applied [duplicate]

When we applied a forward bias across a PN junction, the barrier height of the depletion region reduces. What will happen to the energy bands when we apply the forward bias greater that the built-in ...
2
votes
1answer
90 views

Dynamic energy and dynamic power in microprocessors

In a class I'm learning about dynamic energy and dynamic power and the notes seem to be incomplete. ...
0
votes
1answer
97 views

Charging of Cell Phone Batteries and Electricity! [closed]

Does charging an already charged battery of cell phones/laptops consume electricity? Whenever my cell phone becomes fully charged while charging, it asks me to remove the charger from the socket to ...
0
votes
2answers
59 views

Energy meter design/mcp390x

I am considering the mcp390Xa series for a energy meter project. What I am not understanding here is where the voltage part of the watt calculation is happening. Is this up to the micro to measure ...
2
votes
1answer
150 views

Extracting the Most Energy From a Capacitor

I have a 5V super capacitor which I'm trying to extract the most energy from in the most efficient way possible. This capacitor is tied to the input of some regulator (which is the question of this ...
0
votes
0answers
79 views

Measuring consumed energy with MCP3905A

first of all sorry for my English because I'm Italian. I'm trying to measure consumed energy with MCP3905A evaluation borad. ...
1
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2answers
108 views

Ohm's Law vs. Conservation of Energy Misunderstanding

I am currently misunderstanding the relation between Ohm's Law and the law for conservation of energy. I am referring to the example (in the book "Foundations of Analog and Digital Electronic ...
5
votes
3answers
390 views

How long can I practically power an IC with a capacitor?

If I have, for example, an IC that draws 10mA @ 3.3V, how large of a capacitor would I need to power it for 2 minutes? 5 minutes? I understand that using capacitors to power an IC is not the most ...
2
votes
6answers
914 views

Difference between Voltage source and Current source?

So what's the difference between a Voltage source and a Current source? Aren't they the same? Because after all they are related with the formula \$V = IR\$. So it means that If we produce a voltage, ...
1
vote
2answers
355 views

Connecting two capacitors in parallel

Two capacitors are parallel connected with an open switch. Both have a different capacity in which: $$c_1>c_2$$ and both charged with a different voltage $$v_1\neq v_2$$ and now we close the ...
5
votes
4answers
295 views

Do real and reactive energy exist?

Are there any such things as real and reactive energies just like real and reactive power? if so, how is reactive energy dissipated?
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3answers
67 views

Energy of a signal [closed]

In signal analysis we work out the energy of a signal. We get a number and thats the end of the story, but theres no explanation of what it means in practise. If it was just some abstract mathematical ...
0
votes
2answers
298 views

3-phase energy meter with CTs

I need to measure 3-phases. Usually I would use CTs on the differential port on a LTC1966, then connect Vout+ to an ADC port on a uC. I do that on a 1-phase application. The problem is now, that we ...
3
votes
1answer
920 views

Logging measurements from an analog Gas Meter

I want to capture a gasmeter counter to log the gas consumption in my database. Problem: till now I did not find a way to read the meter. I tried a sensitive hall sensor that could react on the ...
3
votes
2answers
664 views

Arduino: How can one control a 2-wire DC motor with PWM?

I want to control the speed of a two-wire DC motor using PWM. I already managed to control a 4-wire motor, but now I need to use a two-wire motor. I would connect it to the Arduino directly, but the ...
-1
votes
2answers
104 views

How long should I leave the light on? [closed]

I'm not sure if this qualifies as electrical engineering, but I remember my old physics teacher at school saying that if you switch a light on in a room and you're planning to return relatively ...
0
votes
3answers
142 views

Is the energy flow due to a an alternating current constant or cyclic

I understand that the Poynting vector shows us that energy flows in the region outside, or between, conductors, but the maths gets too deep for me to discover, when the current is alternating, whether ...
0
votes
0answers
289 views

Calculating true power/energy usage from battery on smartphone?

I am having some problem to calculate power consumption from android smartphone... First my setup: Android smartphone is connected to PC with USB. Both smartphone and USB do not provide their own ...
1
vote
0answers
96 views

When a smartphone is connected to a charger (USB), does it use battery or charger as it's main power supply? [closed]

When a smartphone (fully charged) is connected via USB to PC (or to charger) does it uses charger or it's own battery as main power supply? Battery is supplying about 3.8-4.1 V and USB ~5V.
-1
votes
1answer
227 views

Typical Power circuit for smartphones? Correct energy measurement? (Nexus 4, iPhone.. etc)

I am trying to perform some energy measurements using smartphone. And to make sure that I am performing my calculations correctly, I been trying to find any examples of typical power circuit in ...
6
votes
2answers
369 views

Where does all the power consumed by a CPU go?

Where does all the power consumption of a CPU go? Does all the power drawn by the PC's CPU get transformed into heat? Or does it get transformed into part heat and part some other kind of energy?
7
votes
3answers
1k views

Does higher resolution of LCD/LED display mean higher energy consumption for the very same matrix size

If two mobile devices being compared have exactly the same LCD/LED screen (matrix) size and exactly the same battery, will the one with higher resolution have higher battery consumption and thus will ...
2
votes
2answers
121 views

charge extraction from solar cells in low light conditions

This is probably not that deep a question, but how can one extract power from panels in low light? A 6V panel would dip to ~2V or so, and power output would sink lower. In conventional systems, how is ...
-2
votes
1answer
69 views

power source unit for two devices

I have two boards that need 2.5A each and 12V for input. I do have a cable to split the DC, like this one ...
0
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2answers
78 views

Kilowatt hour from Complex power

How can I calculate Kilowatt Hours from: Complex Power = 1,5 kVA Electrical current consumption = 10 A It's three-phase electric power.
2
votes
2answers
307 views

Finding the total energy of the network in steady state

i got a network below in steady state im trying to find the energy in the network by the capacitors and inductors. simulate this circuit – Schematic created using CircuitLab My attempt ...