Questions tagged [power]

Where power is a primary concern for the design under discussion. Use the "low-power" tag when that applies.

4,089 questions
42 views

3 Phase vs line to line [duplicate]

Say I have the following three phase wye configuration: Source Let’s also assume that all three loads have the same constant resistance, therefore in this case the system is balanced and the neutral ...
92 views

Determine the power dissipated in W in the 5 Ω resistor [closed]

simulate this circuit – Schematic created using CircuitLab Excuse me for my really bad use of the schematic feature I just didn't know how to switch to the phasor domain. Anyway, I'm asked to ...
94 views

Identification of 2-tab power connector

Can anyone identify the correct plug for this socket? Those are 6.3mm tabs, for mains voltage and around a 10A load. Many thanks!
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Does voltage and current have an inverse relationship in DC power transmission?

Let's suppose that we want to transmit a 1kW via DC generator with the below voltage level. From this we can see that the relationship between the DC voltage and current is inversely proportional, P ...
576 views

What is the meaning when we say power of circuit having a clock frequency 100Hz is 2W?

When we say clock frequency is 100Hz, then there are 100 clock pulses in one second. So when we say power is 2W, is it 2W for 100 cycles or one cycle ? Or is it anything else?
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Maximum Vin on load switch ICs

I'm trying to determine whether the absolute maximum rating for Vin on load switch ICs applies for when the switch is both open and closed. When the switch is closed, it makes absolute sense to me ...
27 views

Symmetrical Component Analysis Circulating Current & KVL

I was reading in John Grainger Power System Analysis and have a question in mind. Below is the delta connection of an unbalaced 3 phase system with unsymmetrical loads Z_{\Delta 1} \neq Z_{\Delta 2} ...
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Distribution-side voltage regulation and Low voltage ride through (LVTR) curve

Nowadays, I see that photovoltaic systems have Low-voltage-ride-through capabilities. So in case of a fault, when the voltage is decreased, they remain connected to the grid and provide reactive power ...
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Not Understanding Grounding in an Electrical Circuit

This might be a stupid question but i am just a little confused about grounding/earthing. Specifically for example in a home when some electrical appliance faults, the current will go to ground since ...
91 views

CCTV camera running 700 ft [closed]

I an trying to run a CCTV 5mp camera from the end of my long driveway to my DVR. Using RG59 18/2 awg 700' 12v dc. I get some voltage drop when IR LEDs turn on at night and makes the camera turn off. I ...
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Isolated DC/DC converter application circuit / usage

I'm trying to find a basic application circuit schematic for an isolated DC/DC converter – this one specifically: DCWN03E-12 – but I'm having no luck so far. The thing that led me to this particular ...
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Unleveled vs Leveled RF Power

I'm reading over a manual for a RF generator and I've come across the terms leveled and unleveled RF power. I'm curious what the difference is between leveled RF power and unleveled RF power.
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Adding an optional external power supply to Arduino Shield

I'm designing an Arduino shield that uses two sets of Adafruit's NeoPixel arrays. NeoPixelRing (D2) can be powered from the arduino, but the optional ...
117 views

6 volt drop to 1.2 volts

I am working on a circuit for my deer feeder. I now have a 6 volt power source running the spinner on the feeder and it has a 6 volts solar panel recharging the battery. I made a new circuit control ...
34 views

What if voltage is decreased for an electrical fan (DC Motor)

Will the speed of rotation decrease or increase? I have an idea of Lorentz Force and all that. Use P=VI and V=IR to explain this to me please. I can't understand what will be the outcome of decreasing/...
4k views

Does USB supply a “constant” 5V or “up-to” 5V?

I am trying to reverse engineer a digitizer inside an old laptop. I am fairly certain it is a USB device because I noticed a twisted pair of cables next to a ground wire. Just to make sure it is USB I ...
103 views

Ability of a 100km power transmission line to radiate 50Hz EM waves?

This is about confusion of relating antenna radiation theory to power lines. Assuming a straight 100km or even longer possible power transmisson line with 50Hz frequency. What can be said about the ...
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Why the actual charge current of a battery is not improving when I shifted to larger current capacity battery charger power supply? [closed]

I'm trying to change my current battery charger power supply to the higher current capacity power supply but I cannot see much variations in the o/p of battery current. I'm using two battery charger ...
20 views

Correct way to calibrate SDR RX into a measuring receiver

While playing with my SDR (Software Defined Radio) Board, I was interested in performing a TX output power table at different center frequencies and TX antenna gains. However, unfortunately, I do ...
42 views

Problem with 2G Modem's supply power

I want to run a 2G Modem HL6528RD. I provide it with 3.6 V, got from the following circuit : I finally manage to make it work but the problem is that if R108 is mounted, the modem doesn’t work, (the ...
72 views

Producing clean power with multiple switch mode power supplies

Thanks, I am new to using this site, I apologize for my vague post earlier. Here is a schematic I been working on. The project requirements are 5VDC, and 20VDC. The 5VDC is to power the ...
36 views

max. switching power of relay in datasheet

I want to use SPST relay to control resistive load as well as inductive load i.e. ceiling Fan (Load<150W). I used the 5VDC relay (HF46F-G) which is capable of 7A current, 250VAC. Datasheet: http:...
49 views

PCB design for MAX1709ESE

I am thinking of using MAX1709ESE step-up converter in my DIY project, and from the datasheet I have found that the chip is manufactured in SOIC16 case without a thermal pad (as opposed to MAX1709EUI+)...
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Correct way to compute the power of a pulsed signal

I'm developing an application with my SDR Board and I've managed to produce a calibration table to verify the output power of the transmitter for every TX configuration of antenna gain and IQ digital ...
66 views

What is this adapter and what can I replace it with for simpler operation?

My church plant uses the D3540 pager - https://www.microframecorp.com/d3540-4-digit-wireless-visual-pager-display We have to setup and tear down the pager system every week. We have to manually wire ...
24 views

Output TX Power with complex impedances

I'm developing an application with my software defined radio (SDR) Board and it is very critical that I have some control over the actual power I am transmitting at every time. In order to do this, I ...
61 views

Weird behaviour of a bath ventilator [closed]

I have a weird behaviour of the bath ventilator. The make and model: Rotheigner Air Basic 100. When I switch it on it is working for 1 second and stops until I disconnect the power and connect it ...
82 views

Can a 3W pot be connected to a 5W LED baton? [closed]

Situation: I got a LED baton and the brightness was higher than required. I added a regular 22k pot in series to it, and achieved lower brightness, but within a few seconds, the pot was burnt. I ...
74 views

Diode OR 4 batteries

I have 4 batteries that are capable of providing a continuous 10 amps each. They will be connected in parallel to drive a motor controller with the intent on delivering 30 amps of continuous average ...
29 views

Grounding Multiple Devices

I am designing a motor controller with an Arudino, UBEC, and ESC. The Arduino will control Servo Motors and Brushless Motors. I want to make sure I understand how to hook up all the devices to avoid ...
75 views

tilt switch to activate power socket

I am after a way to activate a 300 W LED lamp to come on when a trampoline is jumped on and to turn off when the mat goes level again, then back on when jumped on and so forth. I was thinking tilt ...
77 views

How do we compute power from current and voltage samples? Can we quantify its accuracy?

I have a datalogger that periodically samples current values by measuring the voltage across a power resistor connected in series with a battery and sensor (the load). The datalogger also samples the ...
48 views

Balancing Power in a Simple Circuit When not all Wattages are known

I am having trouble solving the following problem. I understand that the net power should be 0, but it seems that there is no way to determine the power of elements 2, 3, and 5. How would one go about ...
67 views

power planes star connection

I have only one layer for +5V and -5V power lines on pcb. There are about 10 dual supply OPAMPS which get power from Recom RKZ0505D DCDC converter. As I know, star topology is suitable for this. PCB ...
113 views

LED circuit Driver question

I’m trying to set up a circuit with one single LED (NICHIA NV4L144AR Specs: Forward current 700mA, forward voltage 11.9V, 8.3W max power) and a piece of LED strip 0.4 meters long (Specs:input 12VDC ...
58 views

Why is this transistor failing?

I have a Sharp LC-19SB24U Monitor that tends to blow a fuse on the power supply. Every time it does, the FET (FQP8N60C) has also gone bad. So I replace the FET (with thermal paste) and the blown ...
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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 ...
55 views

How to compare power requirements for different control design approaches?

I am trying to fairly compare different control design approaches. As an example, below I present two similar but different techniques which are: Control system with state feedback Control system ...
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how to avoid harmonic on intrrupt for proximity sensor in NodeMcu

i have 5v IR proximity sensor for measuring pulse output attached in NodeMCu using intrrupt pin but it gets a random counter on the harmonic environment. it is working fine in Normal situation what ...
51 views

Convert momentary button to toggle switch?

I have this simple circuit (existing, not mine) that you toggle on and off with a simple push button and when you power it off and back on it stays off unless the button is pressed. I want to set this ...
17 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 ...
142 views

Calculate temperature of kanthal wire per electric Watt

I'm trying to get an estimation of the temperature that a Kanthal (A1) wire would get, when applied an amount of electrical power. The wire is 30cm long. The diameter is 0.3mm (or there about). The ...
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Voltage drop on power bench supply for channel being off

If I measure voltage drop between terminals of my bench power supply (spec) I get -15 mV when channel output is turned off. Why it is not reading 0? I believe it's due to internal impedance of the ...
79 views

Control a MOSFET using tactile switch with single power source connecting to gate and drain

simulate this circuit – Schematic created using CircuitLab I'm trying to build a circuit with 2x NiMH batteries as power source that can output up to 2A when tact switch at mosfet gate is ...
50 views

connecting pam8403 and bluethooth module in series

I am new to this so I apologize in advance for any rookie mistakes. I decided to make a portable Bluetooth speaker. I have a pam8403 and a Bluetooth module: Both of them require 5 V input. Can I ...
125 views

How to generate a high energy electromagnetic wave? Using high voltage or high current?

I am about generating an electromagnetic wave which should be powerful enough. So I should manipulate its electric field and magnetic field simultaneously. As far as I know E amplitude depends on the ...
165 views

Single-line power transmission of 1MW over 35,000km [closed]

This question posted on the physics stack exchange has not received much attention. I thought the audience here might be more able to answer it. Background A space elevator is mechanism to provide ...
46 views

Boost converter output voltage error

I'm using LT3494a to generate 37v from 6v input. This is my circuit. According to the datasheet, this chip can provide up to 40v output, so it should be able to generate 37v. Also, the simulation ...