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

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4answers
36 views

What is capacitance required for this 3 phase rectifier

In the diagram above I want to know the value and the rating of the capacitor that should be used for good rectification The Line to Line voltage is 400 , and by relation Vdc =(3√2 VL)/pi=(3√2 x ...
0
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0answers
28 views

Typical 3g power consumption

What is a typical power consumption of a relatively low power embedded 3g modem (for IOT) during communication?
0
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1answer
39 views

Simple lightweight high power amplifier circuit

I'm looking for a way to amplify a 12V sinusoidal signal to drive a set of transducers at ~120V with an overall power of 100W. The quality of the output signal does not have to be good, simplicity ...
0
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1answer
26 views

Portable power supply for over 300 ws2812 LEDs (similar to youtube video)

I have an idea fro a project which requires a few hundred ws2812 LEDs to be powered using relatively small battery which can be carried. I was wondering how you could power over 300 ws2812 LEDs ...
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1answer
25 views

What telecom satellite data sets require for anomulus propagation investigation

I am going to investigate anomalous propagation like sub refraction, super refraction, ducting and i want to use tale com satellite Paksat1R data in order to check effect of anomalous propagation on ...
0
votes
2answers
78 views

What are the different ways to switch power using a microcontroller (Arduino, Raspberry Pi, BeagleBone, etc.) and what are the pros/cons for each?

I'm using an Arduino to control a 12v water pump for a self-watering plant wall. I'd also like to use the same power supply for both, and probably need surge protection of some kind to avoid spikes. I ...
0
votes
1answer
26 views

Irms to Idc for inductor selection

I'm trying to build a buck converter using one of Power Integrated switches and their online design software lists the inductor rating in Irms. However, most inductors have their current ratings in ...
0
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1answer
38 views

max current drawn from an IC or a circuit

how do i find the max current drawn from a simple circuit with an IC, few resistors and caps. if it's taken from the datasheet, what current rating i should be looking at exactly? or should i be ...
0
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1answer
48 views

Using european telephone cables for own DC power delivery

I have european telephone cables running through my walls to each room, without any connection/socket. Well... we really do not need any hard line telephone connection and I am into DIY projects, so I ...
2
votes
3answers
91 views

solar power ESP8266 microprocessor circuit to turn off when low voltage

I intend to run an esp8266 microprocessor on only solar panels so it is on during the day and off/disabled during low light conditions that do not supply sufficient power. Is there a circuit that ...
1
vote
1answer
52 views

Calculating power with RMS

Suppose I have a rechargeable 70 kWh battery , and I use 120 V rms from my house with a 10 A RMS circuit. To find the max power of this circuit, is it just P = VI, since both the voltage and current ...
0
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0answers
22 views

Joining terminals of LiPo batteries

What are the ways to join terminals of LiPo batteries, except using soldering or spot welding?
0
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2answers
53 views

Power of a capacitor when is connected to a battery

According to definition of power ( current times voltage) since there is no change in charge, the power stored in a capacitor connected to a DC voltage is zero. Since energy is power times time, ...
0
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2answers
73 views

Cable rating - What is the max amp for a 1.5-1.75mm cable?

I have a new hob (magnetic induction plate). It requires 7200W/32A. The power grid's voltage is 230V (Europe). I have already installed a thick cable and I want to use it (it would be difficult to ...
0
votes
1answer
38 views

Harmonic Power Flow

What is the fundamental differences between the conventional AC Power Flow (CPF) & Harmonic Power Flow (HPF)? Is HPF simply a combination of CPFs at different frequencies? Instead of finding the ...
0
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2answers
55 views

Power in AC circuits

When I look at the graph of the power in AC circuits versus time (not the average power I am talking about the instantaneous power) it goes from a negative value to positive. On the other hand, I know ...
-2
votes
0answers
32 views

Laptop power button not working. Where should i look?

Hello i'm trying to fix my laptop's power button. The button is attached into USB adapter module. I checked switch and all connecting pins to motherboard with tester (connection was solid and well). ...
0
votes
0answers
36 views

Solor Panel and Super Capcitor

I need some help trying to figure out the sizing needed for a solar panel and super capacitor. The overall design is a solar panel hooked up to an energy harvesting chip that charges a supercap. The ...
0
votes
1answer
61 views

P channel mosfet battery charging/power selection circuit help

I am a hobbyist and new to this, but I am not sure if my circuit it right. The goal is: To power the rest of the circuit from a DC source, a USB, or a battery, in that order. When there is no DC or ...
4
votes
2answers
106 views

Buck Converting Voltage, to Switch Original Voltage

I'm learning electronics, so I want to sanity check this approach in case I'm missing something. I have an arduino (at 5V) controlling power to a set of lights at 12V, via a mosfet. This is all fine, ...
0
votes
2answers
62 views

Resetting a microcontroller with a button connected to Vcc

I would like to have a way to reset my PIC by removing power from the chip. My hacker self thinks that the simplest way would be to add a resistor between the output of my LDO and Vcc on the PIC, and ...
0
votes
1answer
35 views

Making a battery pack out of 8 cells in 4S2P configuration

I want to make a battery pack of 4S2P using 8cells. Is it better to first make 2 sets of 4 cells each (4 cells joined in series to each other) and then join these 2 sets in parallel or first making 4 ...
0
votes
2answers
53 views

How does the definition of electrical power follow from the chain rule?

Just a small question for clarification. Here's what I know: current I is defined by \$I = \frac{dq}{dt}\$ where q is charge and t is time voltage V is defined by \$V = \frac{dw}{dq}\$ where w is ...
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votes
2answers
41 views

How to get a 5-30 VDC trigger voltage from a A/V receiver? [on hold]

My old A/V receiver had a switched 120VAC outlet that powered on when the receiver was powered on. My new Yamaha A/V receiver (and no new receivers, evidently) does not have a switched 120VAC outlet. ...
0
votes
1answer
72 views

Power supply logic design [closed]

I have three power sources that supply voltages from 3 to 9 volts. This will be going into a positive voltage regulator for stable output. If the third source is present it takes precedence over the ...
0
votes
1answer
36 views

LNK304P unexpected output voltage

I trying to understand what problem with next scheme. I have a power supply which should provide +12V but in my case it's only about 5v in output (checked on 1-2-7-8 and Gnd pins). I have tried to ...
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votes
1answer
48 views

Bad if I use a Higher power adapter for a keyboard instrument requiring lower power and amps? [duplicate]

Can I use a 13.5VDC 1a power supply for a keyboard that requires a 10VDC 800ma power supply without ruining the keyboard? I was told that the keyboard would only draw the power and amperage it needed ...
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votes
0answers
19 views

Parameters associated with power transients

What are the major parameters associated with transients in a power system? I am going to use discrete wavelet transforms for analysing it. So, is it only magnitude, duration and spectral content? ...
0
votes
1answer
46 views

wattage consumption of three phase electric motor

i have a 5 hp motor in my factory . at load, it shows 3.5 ampere consumption ( when tested by a meter). is the consumption accurate? someone told me that 5 hp three phase motor will consume 7.5 ...
0
votes
1answer
43 views

Transformer output connected to another transformer. Measuring 'Real Power' at input of first transformer

I have a watt meter connected to the primary of one transformer to measure power. The output of this transformer is connected to the input of another transformer. The watt meter is measuring the ...
-2
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0answers
77 views

Issue with MANUAL-AUTO logic [closed]

As per the circuit I would be able to control the circuit through the manual switch which is connected to the Digital Input of the controller where 5V DC is looped and other alternate command ...
1
vote
2answers
70 views

Power Factor - What is it a characteristic of?

I always thought it was a characteristic of a powered device, rather than the power source. A generator (whether it's a station or a small petrol powered one) does not have a power factor. I've been ...
0
votes
1answer
65 views

Solar panel subsystem project

I am trying to build a subsystem for a project that I am undertaking in university. An overview of the subsystem can be seen in the attached image. The only difference from my subsystem and the one ...
0
votes
1answer
64 views

Adding 2 cooling fans to an amplifier circuit board

simulate this circuit – Schematic created using CircuitLab I'd like to add (2) 5v .41A cooling fans to this Vox bass amp. What Resistor/capacitor combo (R3/C4) would be best?
0
votes
0answers
45 views

Finding the effective switched capacitance in Intel processors

I need to able to calculate the power consumption of an Intel processor using the equation, P = C * (V^2)*f where C, V and f are the effective switched ...
0
votes
1answer
62 views

Power consumed by an LED in a simple circuit

I am in the very beginnings of studying circuits and am a little confused on calculated Power. If I have a 9V Battery, 4 x 10k Resistors and a single LED, how would I calculate the power consumed by ...
0
votes
3answers
121 views

Should I continue with daisy chaining?

I've been daisy chaining power strips and it was no issue until my friend told me it's dangerous. I was using 2 monitors, fan, desktop,55inch TV, monitor speakers, and a phone charger. And he told me ...
0
votes
1answer
44 views

RF cable with DC power cable?

I have a satellite communication system at office running on C-band. The C-band is downconverted to L-band and carried to the l-band modem. With this RF coaxial waveguide/cable, +12V DC power cable ...
0
votes
0answers
38 views

modify computer power supply for higher voltage

On a computer power supply there are some potentiometers on the secondary side. one of them is in series with a resistor that feeds into a VrefMAIN pin on a voltage supervisor IC. When I turn the ...
0
votes
1answer
23 views

Unity Power Factor Correction from Waveforms

So I needed to find a value for a capacitor (Zx, where the resistive component is zero) to perform power factor correction (PF = 1) on the following circuit: w = 1250 ZL = ...
0
votes
2answers
24 views

Quick Datasheet Interpretation - TI LM1084

Was wondering if someone could give this datasheet a look over in regards to the max current it can source out. It's rated at 5A out, but it says under "Current Limit" for LM1084-5.0 at Vin=10V that ...
1
vote
1answer
68 views

Equation for the average power of a signal

I'm reading the book "Introduction to Electromagnetic Compatibility" by CR Paul, and in Chapter 3, I come across this equation for the average power in the waveform assuming a 50% duty cycle and ...
1
vote
1answer
98 views

Power Transistor for TDA2030 audio amp

I am attempting to make a Stereo Power Amplifier using two TDA2030A amplifiers. I want an output of at least 25 watts per channel. The datasheet shows me that I need to add a pair of power ...
1
vote
0answers
39 views

Atmel SAM MCU (on Arduino Due) only boots after second power up

I am using an Arduino Due as a prototyping board for a microcontroller project. The due has the chip Atmel ATSAM3X8E, with an ARM Cortex-M3 core. I am programming the flash directly using Atmel Studio ...
0
votes
2answers
53 views

Reactive Power in Inductor and Capacitor

Suppose a RLC circuit with AC source. Why the net reactive power in the circuit is the difference of reactive power in the inductor and the reactive power in the capacitor ? As both of them store ...
-2
votes
1answer
93 views

Transistor - Control current flow

simulate this circuit – Schematic created using CircuitLab I am having trouble finding how to limit the current flow from the collector to the emitter of a transistor. (Is it possible? I ...
0
votes
1answer
49 views

Measure current of multiple loads with one sensor?

I have been doing some research for my project which requires to measure power consumption of 8 different loads. For that I plan to measure current in each line and multiply that with the voltage of ...
1
vote
2answers
137 views

Arduino, two buttons powering and digital inputs in the same time

I'm trying to determine if this circuit is going to work exactly as I think: Expected behavior is: When we press S1, arduino turns on and digitalRead(7) will give us HIGH value (INPUT_PULLUP is ...
1
vote
1answer
151 views

Lab Power Supply based of LM317 (Project)

I'm pretty new into electronics, But I do this mostly for educational purposes. Even if there are cheaper/more effective ways to build a power supply, I want it to be based of the LM317. This ...
1
vote
4answers
98 views

Reactive Power in the circuit

Why is inductive reactive power considered positive while capacitive reactive power is considered negative in the circuit ? Both inductor and capacitor consume apparent power so I guess ...