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Questions tagged [energy]

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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Why can the energy of local computing be written as \$f^2\$,not \$v^2\$

I saw this formula in this book: Wireless Information and Power Transfer: Theory and Practice And in the formula 14.8, it said: \$f_{i,n}\$ is the CPU frequency for the nth CPU cycle required for ...
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1answer
25 views

Mosfet or bjt choice for low voltage joule thief application

I make solar energy harvester using joule thief circuit with a small solar cell as the input. The output voltage from the solar cell is 0,5V. But the generic transistor, exactly silicon material need ...
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2answers
58 views

Energy lost in in Peltier device?

Suppose I power a Peltier device to heat up/cool down some water. Then I later use the same Peltier device, in reverse, to convert the separated heat energy back into electricity. I have read ...
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5answers
2k views

Heat lost in ideal capacitor charging

If we use an ideal capacitor to charge another ideal capacitor, my intuition tells me no heat is generated since capacitors are just storage elements. It shouldn't consume energy. But in order to ...
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1answer
48 views

How can i calculate the life of a battery while it is also currently being charged by a solar panel? [closed]

Presuming the battery is using more power than what the panel can produce? 3716 mAh battery Consumption of 250 mA with a rate of 0.7 While I can use this to calculate the battery life, how would I do ...
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1answer
40 views

C=Q/U equivalence for inductor

In order to calculate the time it takes to charge a certain capacitor with value C at a given constant current of a value I to a voltage of value U, I can use: $$ C = \frac{Q}{U} = \frac{I\Delta t}{U}...
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0answers
58 views

Generate energy from waves that move my ship?

I'm currently building a small solar powered robot boat. I expect it to work fine (because why not.. :-) ), but I'm already looking for other ways than only solar panels to generate electrical power. ...
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0answers
175 views

Is the duck (curve) still a duck? [closed]

In 2013 the California Independent System Operator (CAISO) published this image, dubbed it "the duck curve", and took the internet by storm (or, at least the part of the internet that tracks trends in ...
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3answers
48 views

MW of installed capacity

I am conducting research on wind turbines, specifically into how many hectares wind farms use. I have come across the phase 'installed capacity'. If wind farms typically use up 10 hectares per ...
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0answers
22 views

creating artifical neutral point in delta connection

I am trying to measure 3 phase 3wire and 3 phase 4 wire L_L voltage and L_N voltage.Circuit i am looking is common for both. In star connection i will get an neutral point for reference to read the ...
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2answers
937 views

How can I deduce the power of a capacitor from its datasheet?

I am looking for suitable capacitors for a sound amplifier I have designed. The speaker power should be at least 7 watt (for the sound to be loud enough). (I attach a figure of the design) So, I ...
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4answers
187 views

Active Energy, Reactive Energy or just Energy?

I understand the concepts of active power, reactive power and apparent power. I am not sure I am getting the complete concept about the respective energies. I am using an energy monitor to record ...
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1answer
28 views

Temperature dependence of the energy bandgap and Simulink way

I know the equation about the temperature change of band energy but Simulink must find another way to define it like below. dEg=-2.677 10^-4 I can't find a single reference about that equation. ...
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1answer
61 views

Supercapacitor for Wind Energy

I am building this wind turbine project and the problem I am facing is the irregular winds that does not keep the inverters running continuously. I initially decided to solve this problem by employing ...
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6answers
3k views

Why don't we think about battery storage for all sources of electricity on a utility scale instead of just renewables? [duplicate]

One of the repeating solutions that comes up when talking about renewable energy power generation and the intermittency of it is battery power storage. This has got me thinking, it takes hours or ...
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2answers
72 views

Photodiode Output measurement

I'm using Hamamatshu s8559 photodiode to convert x-rays into it's respective energy. I'm using a 10 bit ADC converter. The problem I'm facing is I have no relationship between the Photo-current ...
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1answer
23 views

Peak Period Forecasting in electric grid

I am currently working on the day ahead load forecasting using a regression model over a microgrid level. I wanted to know is there a way I can detect peak period i.e period where demand is high from ...
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2answers
77 views

Hspice does not give correct energy consumption for a RC circuit connected to a DC supply

Here is the circuit I am trying to simulate - a RC circuit driven by a DC voltage source. I measure the output across the capacitor. Assume Voltage source is 1 V. Assume capacitor is 1fF. Case 1: ...
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0answers
25 views

permanent magnet synchronous motor Lagrangian in qd0 frame

I'm trying to derive a symplectic model for a permanent magnet synchronous motor (PMSM) in the rotating qd0 reference frame using a geometric integrator. For that purpose, I need the discrete-time ...
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3answers
46 views

Is there an industry standard definition for “load”?

I come across load meaning either power or energy from time to time in the context of residential loads or load forecasting. As such I was wondering if there is a convention as to whether "load" more ...
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2answers
61 views

Graphical nature of signal energy

In signals, we learn that the energy of a signal is the integral of its square. E.g. \$E=\int_{-\infty}^\infty x^2(t) dt\$ We know that integrals are the areas under the function in a graph. But ...
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0answers
20 views

LLC converter HF transformer

I am searching for a suitable transformer core for my project of LLC converter. Lr and Lm inductors should be built in primary windings. I built a LLC converter with 3 outputs in the power range of ...
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1answer
26 views

Time it takes for B to go to zero with R and L given

Given that your solenoid has inductance L and resistance R with initial current I such that there is uniform B inside the coil, I would like to figure out how much time will pass before B goes to zero....
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0answers
63 views

How to safely switch a big inductive load with a Triac using a capacitor snubber?

I am building a Spot Welder with a big powerful transformer. I have to switch a big inductive load of 70mH (input of a transformer) The switching will be done with an SSR (Opto Triac Zero crossing SSR-...
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1answer
24 views

Why are thresholds for energy detection and preamble detection different in 802.11 standard?

Assuming a 20 MHz band, it is -62 dBm for the data and -82 dBm for the preamble. Source: August 2013 doc.: IEEE 802.11-13/0994r0
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2answers
71 views

What is the effect on kWh if the power company reduces line voltage to a residence? [closed]

We just received our power bill and it is showing a 30% rise in kWh for the past month. Nothing has changed in our home. We were even gone one full week in the month. To make it more interesting, ...
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0answers
37 views

how to compute battery charging power

I have a very basic question about battery charging power. In a very simplified scenario, assume a battery with voltage 3.7 is connected to another rechargeable battery with voltage 3.2 which results ...
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0answers
69 views

RS485 registers for calculating total power consumption (kwh)

I have an energy meter (OHIO A2000) which has been now discontinued by the manufacturer. Anyway, I'm following the manual for extracting energy parameters through Modbus RS485 communication. I'm ...
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1answer
69 views

Determining Battery Charging and Discharging Rate Based on Max Current and Nominal Voltage

I am having difficulty in figuring out some basic stuff and confused with multiple equations. I am working on a simulator which simulate a hybrid vehicle journey for some period of time. During ...
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1answer
33 views

About parallel circuit [duplicate]

Consider a power source supplying 240 v 50/60hz 6amp I know that there is nothing like it but I chose that for my comfort of understanding now if I connect 15 loads drawing 240 v 0.35 amps in parallel ...
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2answers
63 views

In AC circuit will there be a voltage drop or current drop [closed]

For reference purpose consider an AC voltage source of 240v 1amp and there are 3 loads connected to same 240v line one consuming 600 milliamps and another one consuming 300 milliamps.now if i add ...
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1answer
52 views

How is the energy consumption of a ciruit component calculated?

I know that watts are equal to amps times volts, and that watts are a rate of energy consumtion. I have looked at some circuits, but I am unsure of how the total energy use is being distributed. My ...
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4answers
767 views

Relationship between I2C drawn energy / power consumption and data rate

Referring to just what the I2C lines draw, am I wrong thinking that the higher the clock frequency the shorter the time there will be (the same amount of) current flowing through the pullups and thus ...
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2answers
59 views

Do “standby switches” consume energy?

Suppose I have a TV plugged in and it is connected to a power outlet which is also turned on. This appliance is "turned on" and on "stand by mode". It consumes energy I think just to light up that ...
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1answer
55 views

Instantaneous power consumption value

If, for a large motor, you are given cumulative kWh values at 5-minute increments, how would you determine an instantaneous power consumption value?
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1answer
48 views

Hamiltonian-inspired energy function for power grid stability

I'm looking at this paper which proposes an energy function for a 3-bus power system example. I'm trying to replicate the results in the paper but am uncertain about the ...
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1answer
142 views

Is electricity saved by switching off the lights when leaving a room? [closed]

Incandescents are very energy inefficient for sure so they have to be turned off whenever you leave the room. But I have tried to find the answer for CFL lights, some say that it's more efficient to ...
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1answer
70 views

Can I use a USA Led Bulb in Europe? [closed]

I am a software engineer working with an IOT company in the states, Right now I am located in Europe for a month and a half, and have some hardware (light bulbs) that I need to use to finish some ...
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1answer
229 views

Battery Charge and Discharge Time

I am doing a case study on battery back up of a wind system with the following specification: System size: 10 kW which runs continuously for 5 hours per day. Battery Calculations: Battery type: ...
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2answers
68 views

Electrical energy saving [closed]

"You can not pay for the light! This CUTE for years was..." I wonder, what will happen if to do what is illustrated on the picture. I think there are two cases: Hot terminal of left outlet connect ...
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2answers
2k views

How to compare mAh to Watt hours?

I have a laptop with a battery described as: 3 cell Li-Ion 57Wh I would like to know how this compares to a powerbank with 26500 mAh capacity. How do you perform these kind of comparisons? What ...
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0answers
135 views

Is there a theoretical performance limit for Lithium Ion batteries?

Is there a theoretical performance limit for Lithium Ion batteries? I'd like to compare energy density of Petroleum Products based upon what limits can be obtained from stored energy in Lithium Ion. I'...
0
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1answer
203 views

Calculating energy of transient/surge handled by metal oxide varistors (MOV) or surge suppressors?

As I get to know more about the MOV operation, there are more things needed to understand. My MOV (V420La20AP) has Varistor voltage of 680 Vrms (10%) at 1 mA, and maximum clamping voltage of 1120 V ...
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2answers
154 views

How does programming code provide power to electronic circuits? [closed]

I've been thinking about a question and haven't been able to find an answer. The question is that: For instance, an Arduino has a 5V output pin to feed any electronic component. When you code ...
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1answer
145 views

Dual axis solar tracker with singlr LDR

I'm working on dual axis solar tracker project, but the task I was given was to make a solar tracker work with a single LDR (Light Dependent Resistor). The LDR would be placed in a pipe which is ...
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2answers
119 views

In an ideal transformer circuit, how is power transferred?

If I have a system of circuits like this: where Circuit 2 is providing power the Circuit 1, where does the energy come from? Do the inductors store energy? If not, how is power transferred from the ...
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1answer
141 views

How much capacitance/joule/watt is needed on average household' energy storage system with supercapacitor?

I am on the process of making assumption how much capacitance/joule/watt is required on average supercapacitor as household' energy storage system. I plan the design for energy hub to be charged by ...
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1answer
88 views

If counter-emf is zero, why is COE violated?

I've been modeling this thought experiment a for a while now: If in a electromagnetic system, the induced emf wasn't opposing the change, but increasing it, we're getting energy from nowhere, that ...
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1answer
83 views

How does electrical signature devices work when there is more than one load connected?

Now more than ever I see energy monitoring devices like this one that uses "AI" to detect the loads connected to your home electrical network, like the washer or a hairdryer. These devices use ...
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4answers
107 views

Is it really that the electrical energy consumed by a resistor totally transform to heat energy?

My notes say that electrical energy and power consumed by a resistor is totally transformed to heat energy. Is this true? Or could it be transformed into also some other kind of energy?