Questions tagged [power]
Electric power is the rate at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt (one joule per second). Use this tag where power is a primary concern for the design under discussion. Use the "low-power" tag when that applies.
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Measure unbalanced tri-phased power with 2-channel scope
Our robot is supplied trough our own "supply block", which is converting 3 phase AC (without neutral) into DC current and powering a 2 smaller devices directly between 2 pairs of phases.
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I know the concept of per unit, but I don't know why am i wrong
A generator which apparent power is \$120MVA\$,and voltage is \$19.5kV,X_s=1.5p.u.\$. Now it is connected a transformer then connected to a transmission line. The rated value transformer is \$150MVA,...
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Chassis and digital ground in an eight layer PC motherboard
I have GNDC (chassis GND) and GND (digital GND) on my PC motherboard design.
All connectors in my design (RJ45, USB-TypeC, USB-TypeA, HDMI, DP, etc.) are connected to the chassis through the GNDC ...
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Comparing power requirements using AC and DC to power radio equipment
I'm trying to understand the different power requirements for a particular piece of radio equipment that I have. It has the capability of being powered via a bespoke AC or DC power supply.
The AC ...
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LIPO and USB Automatic power selection circuit
I am designing an automatic Power switch between a LIPO battery and a USB as a power input.
The system should use the USB but if the LIPO cable is plugged it has to use that as a power source instead ...
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Boost converter output voltage drops
I'm using an MIC2251 (MIC2251-1YD5-TR) in a design to boost a lithium battery (3.6V-4.1V) to 5.4V for powering a small camera peripheral that requires a typical draw of 80mA. I expect that the worse ...
user220456
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Half Bridge SMPS design
I'm trying to design a half-bridge SMPS. However not able to get the desired output. My doubt lies in the transformer sizing and it's implementation in LTspice.
Specs:
Vs=220 V RMS AC
Desired DC ...
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Connecting the GND of an isolated circuit to the positive side of a 450V transformer output
I moved to a new company that makes very big old-style controlled rectifiers. They asked me to make a new modified, and enhanced thyristor-controlled rectifier. The strangest problem I faced is that ...
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Selecting the current rating of a LDO linear voltage regulator
I'm prototyping with a development board which has a 3.3 V rail and I have an IC that needs to be partially powered at 1.9 V. From my research, LDO linear voltage regulators are ideal for this ...
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How to properly measure a 200 A/5 A CT using an Arduino?
I've seen multiple projects for energy monitoring explaining how to calculate values using a Current Transformer (CT), however, all the CTs that were mentioned have high turn ratios.
The CT available ...
Kristofer
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Self power-off using UPS and GPIO
I'm working on a project that include RPI that needs to be off when not used (cut off the main power for it)
Input power 12V
Charger Unit has input of 12V and charge a single cell Li-Po battery "...
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Optimal topology for high-power small factor SMPS
I'm trying to design a relatively small and compact SMPS for an output rating between 200/300 W (400 V in and 20 V out). The AC input from mains is rectified and filtered and fed to a PFC boost stage ...
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Difference in amperage at the plug vs at the source (three-phase wye, 120 V and 208 V loads)
I'm trying to understand the difference between how my work calculates power at the load vs how we calculate the sum at the source.
We run temporary power and plug in several hundred industrial ...
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What are typical "crest factor" values for significantly non-linear typical household loads?
What are typical "crest factor" values for significantly non-linear typical household loads?
By household loads, I mean anything either plugged in to a receptacle or hard-wired like ceiling ...
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Need help with a DMP3028LSD-13 - PMOS in dual way power path design. Currently, load resistors are needed to turn the path off
I have implemented a bi-directional independent power path using a DMP3028LSD-13 PMOS. When a supply is connected on the A side (power source +5V,) voltage is reflected on the side B (no device/load) ...
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Power Industry - How to determine if a transformer is sufficient for the use
If I have a customer who provides me with their peak kW demand (say, 1000 kW) and wants to know if it is sufficient for them to downgrade from a 2500 kVA unit to a 2250 kVA unit.
Is this determination ...
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Does this launch circuit look correct?
I'm trying to design a circuit which will pass through an electric match to light it on fire from a safe distance, with indicators.
I know it could be done simply and as is, but this is for fun, not ...
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LDO performance improvement
I'm using NCP1117ST50T3G by Onsemi and it is connected 12 V comes from a power AC to DC module. How can I improve LDO's performance?
Output is oscillating respect to noise in the input. You can refer ...
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Calculating period power and average power
v(t) = 5cos(50*pi*t)V
i(t) = 3sin(50*pi*t)A
a. What is the energy per period?
b. What is the power averge per period?
I calculated the period time and I got 0....
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Controllable IC/MUX that can switch between Logic, Variable Power, or Ground
I am working on a PCB project that is meant to be attached to various different devices. Each device attached to it will have different pin-outs. Each pin has to be customized through an interface ...
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IC power supply backup
I'm using this ic
The datasheet for the 23LVC1024 SRAM specifies a minimum supply voltage of 2.5V. I want to use a power supply set at 2.5V, but with tolerance that could be less than that, say down ...
user220456
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Will this 24 V relay driver work?
I am not sure about the 24 V which drives the transistor base. Is this circuit correct? Do I need some modifications?
The current rating for D2 is 200 mA. Is that high enough?
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Battery replacement for 16 VAC
I have a mains power adapter that powers a small model train set. I would like the option to power this off a rechargeable battery, although I'm not sure this is possible, as it uses AC.
My current ...
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How should I select a battery solution for my project? (24 V/150 mAh with recharging)
I'm designing my first ever electrical project and have questions about selecting an appropriate battery solution. I'll put the requirements up front.
Max power draw - 24 V @ 150 mA
Average power ...
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Low-frequency inverter power transformer selection
I'm currently designing a low-frequency inverter from 42 VDC to 220 VAC (effective) that goes up to 300 W.
The block diagram looks something like this:
This is the FFT before the filter:
As you can ...
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LoRa power level contradictions
I've got some LoRa boards that claim 20 dBm transmit power. They do indeed show ~100 mW output power on an old-school moving-coil RF wattmeter.
However, on a spectrum analyser with 20dB + 30dB ...
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Ringing seen when charger is presented to DUT
The following is my setup:
Charger is set to 56V and 15A.
When charger is turned on there is significant ringing measured by the probe directly at the charger terminals. However this ringing is ...
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Schematic Notation
I am reading a schematic to find the current leak of my car battery.
What is the dotted line between the top of fuse 6 and 17?
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DC-DC converter circuit LM5164
I would like to build a DC-DC converter circuit using EasyEDA that can output about 80V from 7 Nissan Leaf battery modules that are about 55V nominal.
I am looking at the datasheet for the LM5164 and ...
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Identify Vintage Power Cord for Sears Electric Tray
I found this vintage Sears electric warming tray but it's missing a power cord. I tried a 2 prong figure 8 cord but the holes were too close together or too small to fit. Here are pictures of the tray,...
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How to generate PWM from based on an AC signal?
I'm working on a project to improve the efficiency of the resonant wireless charging system. For one of the steps to do this, I need to find the phase shift between current and voltage and of \$I_{\...
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Synchronous generator
While calculating this professor first said 200MVA and 25KVA are 1pu because they are rated values. Then he easily find the E filed by Efiled = Vterminal + Armature Current*total impedance(synchronous ...
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FPGA Bank Voltage
If an FPGA bank is physically connected to a regulator voltage of 2.5V and in the software the bank is defined as 1.8V and the I/O standard used for the buffers is also 1.8V, the code compiles without ...
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12V to 3.3V using LM3489
I ran into an issue with the LM3489 not actually attempting to switch the transistor at all. I'm not sure why it won't start up. PGATE sits at 12V, VCC and when watching it seems to make no attempt to ...
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MOSFET Power Switching Circuit
I'm trying to implement the circuit below from here: http://www.mosaic-industries.com/embedded-systems/microcontroller-projects/electronic-circuits/push-button-switch-turn-on/switching-battery-power.
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How to determine noise power and SNR from extinction ratio?
I have a pulse train signal with infinite extinction ratio (ER). I want to add a white gaussian noise to my signal to get ER=15 (dB). I know that ER=P1/P0, i.e., the power level with the light source ...
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How does the electrical power from the output of a generator vary after a fault?
I know that after a sudden generation/load variation there is an imbalance between mechanical power and electrical power at the borders of generators which causes a frequency change according to the ...
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Mechanic and electric power after imbalance in power system?
After a power imbalance (for example a generator disconnection) in the electric grid, generation and consumption are not equal. This causes a dynamic transient in generators described by the Swing ...
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Measure Magnetic Field Circuit
I saw a design of a magnetic field meter circuit at here.This circuit looks like it can measure weak magnetic field such as earth's with only using inductor coil to gather magnetic field and without ...
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Voltage regulation using TL494
I want to use TL494 IC for voltage regulation. For this, I am giving a 2.5 V reference to the inverting pin of the error amplifier and wants to vary a voltage from 0- 5V at the non inverting terminal ...
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nature of the load connected to the electric power grid
I know that loads can be modeled either as constant impedance or as fixed power P and Q. I also know that the majority of the loads are constant impedance type but I don't know exactly the percentage. ...
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Getting rid of AC DC adapters
Getting rid of AC/DC adapters
I'm aware of the above question but feel it didn't address my situation.
Note: Robot meant to be an underwater ROV(Remotely operated vehicle)
I'm designing a robot and ...
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Is there a way to control USB 3 power with an Arduino?
The scenario is the following: we have eight USB 3.0 devices connected to a PC. Sometimes these devices go haywire. The only way to fix them is to physically disconnect and reconnect the cable. I'm ...
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Relative error of power estimation
I'm reading my teacher code for FFT windowing in Matlab and there is one thing I don't understand. When you run the code at the end it says:
...
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GPIO conections to Ground
I want to detect change in on of digital pins of Arduino . First step is connecting digital pin to ground or vcc according to internal condition of pin.
So in ARDUIO i set one of digital pins (GPIO) ...
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Formula for calculating instantaneous power in pure inductive and pure capacitive circuit
According to the material provided by a faculty this is what the formulas were and how they were derived.
According to the derivation we did in class, we were getting:
P = -VrmsIrmssin 2ωt for pure ...
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Impedance relay question
In the example below, I just don't understand why line 2–4 has a larger impedance than line 2–3?
SOURCE
Power System Analysis & Design,
Sixth Edition
J. Duncan Glover, Thomas J. Overbye, and ...
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Calculating battery life considering the capacity drops depending on load current (2 x 4 AA-packs in parallel)
This is a very recurrent question, about calculating the battery life given certain circuit current usage.
This example will be similiar to this one in terms of the battery used and the consideration ...
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Can someone confirm my derivation of the generalized power law from Practical Electronics, 4th edition?
I dont know how to use LaTeX, so I used Mathcha and took a snip from there.
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Transmission Line Power Flow
Background:
So, I recently watched Veritasium's video, "The Big Misconception About Electricity" and EEVblog's response to it.
Here is the circuit in question:
I think understand why the ...
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