# Questions tagged [efficiency]

A measure of the overall effectiveness of a system. For example, in power conversion, it would be the ratio of output power to input power.

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53 views

### Negative to chassis or separate wire?

In automotive applications typically battery negative is connected to the chassis, right. This makes the chassis be at the same potential as battery negative, but when completing a circuit, ultimately ...
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1 vote
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### Would this isolated AC peak voltage detection circuit work?

I have adapted the circuit from Michael's circuit in Efficient method for isolated detection of AC voltage without a stepdown transformer to detect on either side of the positive half-cycle peaks, ...
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### What is the physical meaning to the condition maximum efficiency in transformer?

Mathematically I can see that When Iron Loss = Copper loss there is maximum efficiency, But why is this true? As far as I know Iron losses are completely independent quantities, So I can't understand ...
43 views

### Should the top torus of a Tesla coil be cut?

Dosen't the top load torus act like one turn coil in short circuit? Doesn't it "steal" (decrease) the energy transfer to the arc? As a load, it has an inductive reactance (1 turn solenoid.) ...
36 views

### Gear reduction vs PWM duty cycle limiting

I am wondering about adjusting the output RPMs of wheels in vehicle. Lets assume two situations, in which we are using BLDC motor with ESC, where the PWM is our controlling signal. We have got gear ...
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### Best type of motor/generator to generate from a 10mm linear movement

Firstly, this is not a homework etc question, but am trying to make a proof of concept for something. I have a mechanical force acting on a shaft (threaded bar) moving it in the direction indicated in ...
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### What is the differences between flow control and access control with respect to efficiency?

We first apply access control methods to get access to the channel link followed by the flow control methods to stop the receiver from overflowing. Suppose we are using CSMA/CD in access control ...
1 vote
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### Tricky problem involving power supply efficiency

I have the following problem. My attempt Initally the efficiency of the supply is 83%, so $\dfrac{P_{out}}{P_{in}} =83\%$. The remaining 17% must be power lost in dissipation in the enclosure \\$\...
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### Inversion Power Loss For Powering Home Electronics

I had a question about power loss for powering home electronics/appliances. Let's say in your home/shed you had various electronics that you want to power that all take DC (printer/tv/etc.), and you ...
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### Where does all the electric energy get dissipated in any electrical system?

I know that some portion of the electrical energy is dissipated as heat due to the efficiency, but where does the other energy go? If we are talking about a satellite in space, all of the electrical ...
188 views

### How do we appropriately select the duty cycle in a flyback converter?

In a flyback converter, we have the freedom to choose appropriate duty cycle by adjusting the turn ratio to meet the desired output voltage. The link says Developers will need to know several key ...
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### What's the most efficient high input voltage / low power converter? [closed]

I have a design goal of creating an AC/DC converter whose maximum input power will be 1W @ 230V. The main issue is that most designs I've found are no more than 80% efficient (in best case senarios). ...
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### Another LED Circuit Design Question - higher voltage and bigger resistor vs lower voltage and smaller resistor

I'm an avid DIY'er recycling some LEDs from a TV. It uses 50 LEDs in series, supplied by 160 V, and the PSU says 160 V @ 400 mA. So my target is to provide 3.2 V @ 400 mA in my own circuit. I would ...
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### What is the efficiency of step-up DC-DC "MT3608" at Vin = 2V?

I would like to know: "What is the efficiency of step-up DC-DC "MT3608" at Vin = 2V ?" (E.g. at Vout = 18V , Iout = 200 mA , to be comparable to the curve in the Datasheet) The ...
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### How to factor roof angles and inverter efficiency in sizing a solar PV system?

I want to install a number of Mission Solar 420 W PV panels (pdf) on my roof. By estimating an average of 5 solar hours per day over the course of the year, I believe I need 9 kW of panels. So by a ...
12k views

### Why does this LED bulb have an energy efficiency rating of 'F'?

In my home, I have some halogen spot lights, which have an energy efficiency rating of 'C': I would like to replace them with more efficient LED bulbs, but looking on the Philips website, they claim ...
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### I have modified a simple blocking oscillator. How can the frequency, duty cycle or efficiency be otherwise increased?

In this schematic is a simple blocking oscillator. Note that this won't simulate, as Circuit Lab does not have the type of toroid needed, but if you breadboard or prototype this circuit it will work ...
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### Efficiency of green High Power LED compared to efficient white

Whenever I see color High Power LEDs (for example green 3W on Star) I see disappointing efficiencies: For 520 nm the theoretical efficiency is 683 lm/W * 0.88 (green) = 601 lm/W. But most are ...
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### Why is the peak efficiency higher in Buck-Boost Controller when running below the AM band and lower above AM band?

I have seen this part LT8253/LT8253A, and it says in the datasheet that "The LT8253 can deliver up to 100W output power with 98% peak efficiency when running below the AM band. The LT8253A can ...
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### Class A amplifier efficiency

I am trying to simulate this class A amplifier using Multisim. I need help to measure the power loss and then calculate the efficiency. I don't have to calculate the power loss; I could just use ...
180 views

### Why is there a difference between maximizing power transfer and power efficiency (as in the maximum power transfer theorem)?

The maximum power transfer theorem states that to obtain maximum power transfer from a source with a finite internal resistance to a load, the internal resistance and the load's resistance need to be ...
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### Relationship between antenna impedance matching and gain

This is my first year designing and simulating antennas and I try to understand the relationship between impedance matching and gain. I stumbled upon the term of antenna efficiency which makes perfect ...
1 vote
56 views

### How to increase efficiency of antenna without moving antenna far from tree?

I have designed a monopole antenna at 868MHz frequency. Now I would like to attach that antenna to the tree (wood). But, due to Why does placing an antenna far from the wood increase the efficiency of ...
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### Why does placing an antenna far from the wood increase the efficiency of the antenna?

I designed a monopole antenna at 868MHz frequency. I placed wood as the surrounding material. I noticed that placing the antenna far from the wood increases the efficiency of the antenna. Can anyone ...
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### How can the efficiency of LED emitters be approximated?

The data sheet usually indicates the power consumed and the luminous flux in lumens. The luminous flux per watt can be calculated from this, but this does not allow any direct statement about the ...
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### How can I connect ( and if required isolate a single module ) multiple LI-ion battery modules(with different SOCs) in parallel sharing common load

1.Need to connect two or more Li ion battery modules(having different SOC levels) in parallel with the help of bidirectional dc-dc converters sharing a common load(say 48V). 2.Isolating individual ...
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### How to calculate efficiency of TPS65581 Texas buck converter?

I am using Texas TPS65581 for designing buck converter where I need to convert 12 V to 3.3 V and 1.1 V. When I go through the datasheet of IC, I can’t find the efficiency for my requirement. For ...
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### Spike killer - Why does it reduce spikes?

This application note says that the spikes when the diode stops conducting its due to its reverse recovery time. I thought that the spikes were occuring due to the parastic inductance and the ...
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### SMPS Daisy Chain Regulators or Independent Connection to PSU?

I'm working on a project that requires the following voltages and currents: 3.8V at 2A 3.3V at 900mA 1.8V at 100mA The input power to the system is a 12V wall wart adapter. I've decided I'll run the ...
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### How to accurately measure ~1 A on 3-30 MHz?

I would like to measure the efficiency of an HF (3-30 MHz) class C power amplifier. In order to do this, I have to accurately measure AC+DC RMS current in the order of 1 A or so. Most instruments are ...
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### LED with lower Rth heats more than others

On my IMS PCB I mounted three types of LEDs: https://dammedia.osram.info/media/resource/hires/osram-dam-8405100/GD%20QSSPA1.14_EN.pdf https://dammedia.osram.info/media/resource/hires/osram-dam-...
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### Assess Efficiency of Small Switching Power Supply

First of all, I'm a noob. I just like to tinker around. I would like to find how efficient my little 12v/1a switching power supply is (and many others like it). From some research, it may appear ...
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### AC to DC power calculations? [closed]

I have an ac to dc power supply and it measures at 244.0Vac on the primary side and the secondary side it is reading 21.34Vdc. I attached a load to the secondary side that is drawing 0.390amps and ...
825 views

### How can low voltage, low-current power be efficiently extracted from mains?

If I wanted to drive, say, a 1V 0.1A device from mains, I could step down the voltage with a transformer, but if the device was basically just a resistor (overall), then the resistor would have to be ...
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### Vaneless ion wind generator: isn’t the maximum output theoretically limited?

I was thinking more specifically about the Dutch model of the kind EWICON : https://en.m.wikipedia.org/wiki/Vaneless_ion_wind_generator Here is what puzzles me: If the wind is strong enough to carry ...
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### How is the technique and method to determine the optimum operating voltage of a dc motor

How is the technique and method to do measurement test in order to determine the optimum operating voltage of any type of a dc motor ? as always shown to us in motor specs e.g. ...
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### Energy efficiency in an electrical circuit

I’m in high school and we are going to do this laboratory in which we will have to make two solutions at different concentrations and determine which has the greatest electrical resistance in a ...
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### Peltier reverse polarity

I am thinking about using peltier for both heating and cooling to maintain desired temperature profile in small area (2ft square at max) Can continuously changing polarity damage peltier module and ...
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### What does the HP/kW power rating on the specification sticker of a pump mean?

Pumps have power given as kW/HP on the specification sticker and also efficiency is mentioned on them. Is this power the electrical input power or mechanical output power? For example in this case is ...
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### The most efficient way to regulate unregulated 12V

I need to power a 12VDC device from an AGM battery, of which the voltage will vary from about 10.5 to 14.5V. The device's datasheet does not mention the tolerance on the supply voltage, I'll assume it ...
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### Calculating Efficiency of an SMPS

I was looking through previous posts and couldn't find anything that I was looking for on this topic. The waveform below is the input current to my system, which is also below. The question is, how do ...
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### Lighting System in terms of its efficiency and consumption

I'm curious regarding some matters in my experiment session of Efficient Lighting System. There are 4 types of lamps which we measure the data to fill-in the table as in the picture. Correct me if my ...
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### What's the theoretical efficiency curve of a series motor?

I'm making this post mostly to check things for another post I'll make (if I don't find any error up to this point). I'm trying to calculate the efficiency for an ideal DC series motor as a function ...
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### Search for the most efficient voltage regulator on low current consumption

I'm currently designing a circuit for a long term device that will consume 1-2mA at 3.3V constantly. The system is run with a default lithium polymer battery and I need to get as much time out of it ...
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### Does the density of the brushes used in a DC motor increase efficiency?

I'm doing a science paper about DC motors and efficiency and I need to test one part to see whether or not the efficiency increases or decreases. I think I will do the brushes and I'm wondering if the ...
1 vote
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### How do I choose what type of transistor to use?

I'm working on a project that will have an Arduino Nano 33 IoT controlling a MG996R Servo. The goal is to get the batteries to last as long as possible, as it will always be on, and will only rotate ...
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### Improving transformer voltage regulation / efficiency through construction [closed]

I am wondering what modifications can be done to a transformer during manufacturing to improve its voltage regulation and efficiency?
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### How to calculate how much current is available from Buck regulated Solar Panel

I'm trying to work out how much current my solar circuit could sustain under normal conditions. I have an monocrystalline solar panel claiming 5W @ 12V (17.8V Vmp, 5Wp) based on their data sheet. The ...