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Questions tagged [power]

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

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1answer
37 views

Power consumption for an in-wheel motor

I'm trying to estimate the power consumption of an in-wheel electric motor. I used the formula $$P = T\cdot\omega + K_m\cdot T^2$$ where T is the torque, ω is the motor angular velocity and \$...
-2
votes
1answer
45 views

Run a 12 dc power through telephony cable [closed]

I have a converter (120 AC to 12 DC) which is used for sending alert to outdoor through 30 meters telephony cable. My quistion is ( Is it harmful if someone touch the cable? the output can give up to ...
3
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8answers
3k views

54V 5A DC thru “regular” coax “TV” cable for use as a “poor man's” solar power cable?

In the effort of saving money without having to buy expensive solar cables (and because I have a lot of extra coax cable lying around doing nothing), I would like to use a piece of coax cable (that ...
1
vote
1answer
29 views

Calculating power drawn or ampere allowance

I just want to confirm the calculations for the following scenario. I have an equipment with the following specifications: ...
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1answer
70 views

a weird phenomenon with a 12V black & decker cordless drill [closed]

The background: I have a 10 years old 12V black & decker cordless drill, the batteries died successively, and I connected a 2 pin male plug try to use a PC power supply [PCPS] to run it. What ...
1
vote
1answer
62 views

Stabilizing IR Emitter/Receiver circuits

Need some help making these IR Emitter/Receiver circuits, and their power, more stable. Building a large, 8’ x 10’ LED art installation (in progress details included). LED Butterflies in a grove of ...
0
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1answer
48 views

Heating resistor power limit

This might be a stupid question but, what limits the heat power output of a heating resistor? Is it the temperature that the material can handle, or does the electrical power itself cause a heater to ...
0
votes
1answer
28 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 ...
0
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1answer
37 views

Selecting the Power rating of resistor

In a circuit I design, there is a moment, when a capacitor should be discharged through a resistor. The power dissipated in the resistor has the format of the screenshot in the LTspice. Should I ...
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2answers
46 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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2answers
43 views

Dual rail power supply for audio needs to drive LED too, unsure of design approach

I have a +17V, -17V power supply for a headphone amp I am building, I would like an LED to indicate when the amplifier is turned on, but don't want to negatively effect the audio output by drawing ...
0
votes
1answer
72 views

Switching a USB HDD on and off

I have a PC which I backup to an external USB3 HDD drive from time to time, I manually connect the drive whenever I "remember" to do the offline backup. I don't want to keep it connected all the time ...
1
vote
1answer
38 views

Powering a Behringer MicroMIX MX400 - Car Audio Application [closed]

I am installing a car audio system that will have TWO aux inputs; one in the dash and one in the rear passanger seat are. I decided to purchase the Behringer MicroMIX MX400 mixer. The power spec for ...
1
vote
1answer
35 views

How to wire DotStar LED strip with 6 wires at the start of the strip

I bought some of these LEDs: They have six wires at the start of the LED strip. I thought that perhaps the separate red and black wires were to power the LEDs, and that, for the 4 wire JST, the black ...
0
votes
1answer
33 views

Is there a limit for voltage a PM generator gets to based on RPMs?

I build different small PM handcrank generators for fun, Recently I built a single phase generator and printed myself a couple transmissions. Now as far as I know 3 things affect voltage, speed of ...
0
votes
1answer
90 views

Power absorbed by load resistor

Can someone double-check where's the mistake? The system didn't accept my answer. TASK: Find the maximum power absorbed by the load resistor, knowing that: $$E = 6.6V; R_{1} = 12.1Ω; R_{2} = 14Ω; R_{...
0
votes
1answer
39 views

How does splitting power cables work in ATX PSU?

I came across this Gamdias 650G PSU. Its CPU EPS has 8 pins at the PSU end but it’s split as 2 x (4 + 4) at the motherboard end. There are certain boards that now come with 8 + 4 EPS power sockets ...
0
votes
1answer
108 views

Why smaller is faster?

I have a question regarding to hardware signal. There is a rule says ["] Smaller is faster. [."], which in the link states that In high-speed machines, signal propagation is a major cause of delay; ...
0
votes
1answer
52 views

What is this solar power RC circuit doing?

I am a CSE student working on a project. We are using a solar powered microcontroller. The solar panel's power goes through a fuse and an RC circuit with a varistor to the charging system. What ...
1
vote
1answer
36 views

What is the parasitic resistance due to an IC package in a mosfet? (or any package)

How much resistance does the package of an IC contribute to the paraistic resitance of a circuit? (most applicable to mosfets)
0
votes
1answer
35 views

WPT compensation topologies

I'm experimenting with compensation topologies for inductive WPT systems and have a small confusion. The general WPT industry uses compensation networks to cancel out reactive components in the ...
0
votes
2answers
37 views

The Relationship of Power and Heat to Length of a Resistor

I have two sections of nichrome wire. They are identical in every way (gauge, etc.) except one is twice as long as the other. If I made it so the short nichrome wire received about 8.485 V and the ...
0
votes
1answer
20 views

Understanding Undervoltage in LTC2965 - 100V Micropower Single Voltage Monitor?

The undervoltage specifications for this IC is a bit confusing to me as this is the first time I'm working with these kind of circuits. Aim : I want to monitor the voltage of a battery pack (...
2
votes
1answer
429 views

Purpose of MOSFET in this circuit

I am failing to understand the purpose of the MOSFET in this circuit from Adafruit Feather board. The FET is connected with source and drain reversed comparing to typical high-side pMOS switch, so ...
1
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2answers
44 views

Connectors for arcade buttons and connect 12V LED to a 5V tollerant micro

I did buy a board from this site, which basically allow me to connect buttons, switch and other controls with ease and no need to program anything: http://derekspearedesigns.com/dsd-36-button-...
-1
votes
1answer
46 views

Regulating High Power Wet-Cell Battery (Accumulator)

I'm currently working on long-term remote-sensing & data-acquisition. Thus, I'm planning on using 12V 45Ah wet cell battery (accumulator) for the supply. The system consists of microcontroller ...
1
vote
0answers
27 views

MPU6050 hangs on ESP32 when operated using a battery on custom board

We are facing a very peculiar problem. We are designing a board based on ESP32 with various peripherals like motor drivers, sensors etc. We are using GPIO 4,5 on the ESP32 as I2C lines and have hooked ...
0
votes
2answers
75 views

PC power supply charge 12v battery

Two part question. If I take the 11v and 5v, with diode to prevent 11v to flow to the 5v, will I get 16 volts? And will it change a 12v battery? Last how can prevent overcharge? Also this is an ...
11
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4answers
2k views

Am I exceeding the maximum ratings?

I'm using LMC6482 opamp with +/-15V rail voltages and having weird behavior. This means Vcc is +15V and Vee is -15V in my case. Am I exceeding the specs? The jargon in the datasheet is not clear or ...
0
votes
1answer
40 views

What practices would improve this scenario for the power transfer

As a part of a measuring project by a mobile phone on the top of a 100 meter tall mast, the mobile phone will be powered by 5V DC of a DC-DC converter output where its input voltage is 12V DC on the ...
0
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1answer
121 views

Class C amplifier low wattage

I am an EE student and my final project was giving to us without explaining what power amplifier are or how to design them. After researching and working on designs for about 40+ hours, I have come up ...
0
votes
1answer
51 views

What is the best starter adjustable power supply for pretty cheap (preferably ac/dc) [closed]

Please I am just a kid no $8953739857239875 power supplies. Btw I am an inspiring electrical engineer and I'm 10 so I need a bit of help so I don't how do I put this nicely, ahem trip the breaker if ...
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1answer
50 views

Converting 5V to 3.3V with 100mV ripple max, preferably without board

I am working on a project in which there is an existing enclosure, an existing power supply board and a bought board that I need to interface with. The board I need to interface with needs to receive ...
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0answers
19 views

Logical problem for power path management chip

It's my first time to use a power-path chip which can switch power supply from DC/USB/Battery. I find a logical issue about using this chip and don't know if anyone can solve this problem. According ...
0
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0answers
36 views

Understanding loads on panel board schedules

I need help understanding why loads are divided by phase on panel board schedules, when the current travels through all of the phases connected to a load. I’m going to try to explain it as best as I ...
-1
votes
2answers
112 views

What will happen if I powered a 24VDC device from a 27.8VDC power supply?

I have a device which has a power input from 12-24VDC Auto select and 250 mA load. I connected it with an online DC UPS which has an output of 27.8 VDC on grid mode and 24 VDC on Battery Mode. I ...
0
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2answers
83 views

Capacitor charging efficiency with a constant power source

I have a question. It is easy to derive the efficiency for loading a capacitor from a constant voltage or a constant current source, basically because exponential functions and constants are very, ...
0
votes
1answer
66 views

Resistor between GND and + 5V in Arduino

I design a board based on ATMEGA328P (as in Arduino UNO). Now I am busy creating a power line. My controller will be installed on the electrical panel, so I need to provide a reliable, noise-resistant ...
3
votes
1answer
119 views

How to power a OLED 128x128 display from 3.3v microcontroller board?

I recently purchased a small 1 inch OLED screen. In the datasheet, it shows the max power requirements as: Operation: 3.5v Logic: 2.6v IO: 3.5v Display: 13.5v I figure I can directly connect the ...
2
votes
1answer
87 views

How fast do power plants need to respond to demand?

I've heard the layman's description of electrical grid response time before - it usually contains the word "instant" or "real-time". But I'm interested in the actual response times of the various ...
0
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0answers
49 views

Strange noise from speaker

I have speaker connected to raspberry pi through amplifier circuit. But I have this annoying noise coming form speaker. Could anybody help me? I have motors connected to same battery and one linear ...
0
votes
1answer
36 views

3 phase voltage problem when connecting to servo

I have 380V 3 phase with the following line to neutral voltages: L1: 238V, L2: 234V, L3: 224V. The system has a single phase servo driver that takes in L3 and N, however when hooked up L1, L2, and L3, ...
0
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3answers
91 views

Chimp climbing wires not electrocuted? [closed]

Reference video: https://www.youtube.com/watch?v=U5-Fy4ULdPg The chimp is climbing both wires out of phase (i would have to assume, it is in Japan), do the power lines have to be closed for the chimp ...
4
votes
2answers
98 views

Buck, Boost..etc Is there always an IC for that?

First of all I am still in school so perhaps I have not been exposed to material that may answer this question for me. I have recently become interested in power electronics. I have purchased a book ...
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0answers
31 views

Capacitor value for power supply [duplicate]

I am designing a power supply that will take a standard wall outlet 120 VAC 60 Hz main and using a 12:1 transformer to step down the voltage to 10VAC. Then using a bridge rectifier and LM7805 to ...
0
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2answers
95 views

Confusion with relating thermal resistance temperature, and electrical power and heat sinking

What is meant by the following?: In general, a device with a thermal resistance θ equal to 100°C/W will exhibit a temperature differential of 100°C for a power dissipation of 1 W, as measured ...
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1answer
53 views

How does soft start work in TI buck regulators?

I am planning to use "TPS54341" in my design. I am curious about how the soft start circuit internally works in TI regulators. The datasheet explains to how to use it, however, does not go in much ...
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0answers
14 views

Derive an expression for the current of a RLE rectifier

I'm trying to calculate an expression for this RLE rectifier: simulate this circuit – Schematic created using CircuitLab With \$R=2 \Omega\$ \$L=20 mH\$ \$V_{DC}=100 V\$ \$V_{m}=120 V\$ \$...
1
vote
1answer
62 views

How much power do power stations in parallel supply?

In modern power systems, the power is supplied by effectively connecting multiple generators in parallel. However, not all these generators are equal, some stations supply more power than others (I ...
-1
votes
0answers
39 views

2 MOSFET DC to AC Inverter Design (Wireless Charging)

For one of my projects, I am trying to create a wireless charging station for a LiPo battery. For my input, I'm taking the standard 120 Vrms, 60 Hz voltage source I get from a outlet. From initial ...