Questions tagged [power]
Where power is a primary concern for the design under discussion. Use the "low-power" tag when that applies.
5,474
questions
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20 views
How to find 3rd party models to import into LTSpice?
I am trying to design a 12 V to 120 V power inverter and most of the schematics I have found need a 2N5877 NPN bipolar transistor. I cannot find any resources on how to bring in the model into LTSpice ...
0
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1answer
36 views
Can smartphones power a MCU circuit through an NFC tag?
NFC tags are passive devices and get their power from the NFC reader/writer. For my question, I'm specifically asking for recent smartphones as NFC readers/writers.
Does the phone transmit enough ...
-1
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0answers
28 views
Confusion about flux linkage
When talking about the flux linkage in a coil, we take it as N(number of turns) times the flux per turn.The way I understood this is since we would like to know the relation between the EMF induced ...
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2answers
49 views
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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23 views
Can I use 2 H-Bridge for drive a motor?
I've a 12V 80A motor, for drive this i'll use a H-bridge with mosfet, in order to divide the current per H bridge we can drive a motor with 2 H-bridge? I'll use mosfet, we cant put mosfet in parallel
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4answers
63 views
TO-247 case maximum current
I've this TO-247 MOSFET
http://www.datasheet.es/PDF/203551/2SK3271-01-pdf.html
how much current will support this case? I've to control a 12V 80A DC Motor
0
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1answer
36 views
What determines the power requirements of a IC
This is more of an acquiring more knowledge question.
I have used a few ICs, such as the 741 op-amp, AND, OR, NAND gates, etc.
I have also used a few micro-controllers like the atmega32, atmega328, ...
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33 views
Need help identifying this SMD
I don't know what this component is. It's found on an adblue ECU for Citroen. I suspect it's faulty and need to order it.
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2answers
79 views
Redesigning MOSFET switches
Consider the two circuits below, the first is the original:
When HIBERNATE goes high, it switches the MOSFETs Q1 and Q2. However, because of the 10 kΩ bias resistors built into BJT Q3, it pulls ...
0
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1answer
25 views
How to estimate the current driven by this uC board for this operation?
I want to power this uC board through its E5V power input pin as shown in below table:
The power source for the E5V pin will be the +5V Vcc pin of this FTDI converter. And in its datasheet the ...
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0answers
37 views
Can I use an Apple charge Cube (5W power) through a Ripcord 9V to USB to feed a Roland SP 404 (2.7 W draw) Safely?
I am asking this as I want to be extra sure this setup does not damage my 404 Sampler as its an expensive item of mine and it's very dear to me so I want to be careful. Here is the scenario:
I have ...
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1answer
48 views
Power Factor in Switched Circuits
Suppose we have a residential lighting dimmer switch circuit, where the output power across the load is controlled by the phase (alpha) of SCRs. Depending on the phase, the SCRs will essentially chop ...
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0answers
44 views
Autotransformer equivalent circuit
I am trying to find an equivalent circuit for autotransformer. But there is no any source about it. I tried to solve something about it. Can anyone have any idea about it?
2
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3answers
66 views
Buck Converter Inductor current at Steady State
I am trying to learn about Buck converters from the below page.
https://www.allaboutcircuits.com/technical-articles/analysis-of-four-dc-dc-converters-in-equilibrium/
Below line is confusing me ...
0
votes
2answers
69 views
Isolated power supply to the DIY projects
I am very new to electronics and electrical engineering background. I am working in an electronics engineering job for the past 4 months.
My question is: what can I use or what is the best way to have ...
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0answers
16 views
Is it possible to drive a 6 or 5 lead stepper motor with 3 phase inverter/bldc driver
I wanted a good way to test my inverter circuit and all I have is a 6 lead stepper motor and a 5 lead stepper motor. Would this work for testing? I have no idea how I would wire the motor. I own a ...
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0answers
26 views
DC motor related problem [closed]
I am designing a micromachining setup for which I need to supply voltage to the spindle of the dc motor. Will the motor damage if we apply a DC source to the spindle?
2
votes
2answers
66 views
Power factor and recitfiers
If I filter the output of a rectifier using an LC circuit on the output, the input source would have a current draw with a square wave shape. I know that a lot of commercial transformers like ...
0
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2answers
52 views
Understanding stepper motor voltage and torque relationship
The specs of this Stepper Motor say at a voltage of 3.36 V and phase current 2.1 A, the maximum holding torque is 65Ncm. I'm confused though as on the datasheet there is no voltage mentioned, only a ...
0
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4answers
62 views
Understanding power ratings
So my previous question here confirmed what I thought, to calculate the power dissipated in a component, take the voltage across the device and multiply by the current.
But why do some devices have a ...
0
votes
1answer
46 views
Understanding a diode's power rating
I thought I found a suitable diode for a project I am working on, it has the correct current and voltage ratings, but then I noticed the power rating and now I am lost.
The diode in question is the ...
0
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0answers
48 views
Two phone batteries connected in series not working
I have two, fully charged, 3.7V standard Nokia phone batteries, that I want to connect together to use as a 7.4V battery, I connected the (+) of one to the (-) of the other, and then tested it but it ...
0
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1answer
48 views
How come the microcontroller of this board is being powered in this configuration?
I have this development board with the following pinout:
And I am using the following FTDI to USB interface to communicate with a PC:
Here is a photo of the board and the FTDI wired to the board ...
0
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1answer
55 views
I'm fixing my Nintendo Switch [closed]
My Nintendo Switch suddenly wouldn't turn on or charge. Nothing on the screen, no reboot/reset trick I have tried worked. I often used a normal USB-C instead of the official charger, which might have ...
6
votes
8answers
1k views
Need device with poor power factor
I'm looking to calibrate an energy meter.
As a part of that process, I need to cheaply find a device that can create a power-factor of 0.5, in order to calculate the required phase correction.
The ...
0
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1answer
37 views
Measuring current usage in a wheelchair power assist device
I am working on wheelchair configuration methods to reduce upper extremity overuse syndrome in daily users. I want to compare two tire types over a course that consists of obstacles that place strain ...
0
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0answers
26 views
How can I at least estimate the optical power that an RGB LED radiates given the typical parameters?
How can I at least estimate the optical power that an RGB LED radiates given the typical parameters - say luminous intensity in Candela or Luminous efficiency - from a data sheet? Assume this is a ...
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2answers
49 views
Transformer Power on the Primary and the Secondary
I am confused as to the power of the primary and the secondary of a transformer.
An elementary textbook says the power on the primary and the secondary are equal (and therefore there is no power gain ...
0
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1answer
71 views
What are these metal plates on this car battery charger/starter output and what is their purpose?
I was trying to figure out why a car battery starter/charger (input 220V, output 12V wasn't working and when I opened I try following the wires to see what the circuit is, but then I run into these ...
1
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1answer
36 views
Op-amp Power Dissipation Calculation for a pulse output
I am trying to calculate the power dissipation of the op-amp for a circuit as below. I am wondering if I did it correctly. Can anyone provide any tutorial on this?
So this opamp will output ...
0
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0answers
38 views
Trying to find this specific manufacturer for a diode
I am trying to find these specific diodes and who made it. Thanks for your time in advance. They could be tvs diodes also
0
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1answer
28 views
Power mux LTC4412HV not doing what I expect
I have created the following circuit:
Following are the variables:
VPOE: 12V supply
VEXT: external supply between 10VDC and 34VDC
VSWITCHED: any voltage between 10V and 36VDC that goes to the load.
...
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0answers
45 views
My 30A PDU is drawing 20.5A. It's L6-30P plug gets hot (65°C. Ambient: 35°C). Is this safe?
I have a home server setup that is drawing 20.5A from a dedicated 30A line. The power is supplied via a PDU rated for 30A (240V). The PDU's plug runs a bit hot, and I'm nervous if it would be safe to ...
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2answers
58 views
Can I power a 35 Watt light fixture over a thermostat 5-wire?
I would like to add this light fixture to my ceiling in an area that only has a thermostat 5-wire coming out (something like this). (The other end of the thermostat wire travels about 15 feet, ending ...
1
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1answer
82 views
Increasing current with constant voltage
simulate this circuit – Schematic created using CircuitLab
I got a sine wave from an STM32 DAC.
Its voltage is 2.64 V. I wanted to amplify it. I used this schematic. Its gain is 4.3. I got 11....
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0answers
33 views
Low-Standby Battery Power Button Circuit
I return with yet another power switch circuit for an entirely new project! (Yeah I do a lot of robot projects lol)
So basically I designed a circuit to turn on/off a battery-operated device from the ...
0
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1answer
30 views
LE33CZ LDO 3.3V regulator output issue
I'm trying to understand why with this very easy schematic, I got with my multimeter:
5.2V between the 5V pin of the USB breakout and GND: OK
0V between the GND of the LDO and the GND of the USB ...
2
votes
1answer
93 views
USB and Battery switching circuit not working [and buck boost converter not working either]
I am an absolute beginner when it comes to electronics and this is my first circuit, so please excuse my ignorance and thank you for your patience and help.
I am trying to build a circuit which ...
1
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2answers
92 views
Convert 15 minute kW readings to a monthly kWh total
I have metering data (kW) in 15 minute intervals that I am trying to get a monthly kWh total for...
I simply summed the entire kW range, then multiplied it by hours in the month 745 (total number of ...
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1answer
62 views
An OR power supply circuit
consider the following circuit:
This image shows a simple "diode OR" power supply switch. I am trying to derive the cheapest circuit to obtain this functionality (the given circuit does not ...
3
votes
1answer
63 views
Calculation for IC lifetime for supply voltage overvoltage
What calculation can be used to calculate the lifetime of an embedded processor (<28nm process) when subject to a slight overvoltage?
The supply rail in question is for analog portions of the ...
0
votes
1answer
45 views
Power strip with individual time delays for each socket
I am to purchase a power strip that has programmable time delays for each socket. What I would like to happen is once the power strip receives power, the first socket from the strip counts down from 2 ...
0
votes
1answer
27 views
Complex power reaching and leaving 2 Current Sources
Given the following circuit, where the voltage of each source is unknown:
I'm trying to find the complex, active and reactive power that reaches and leaves(provided by) each of the two voltage ...
2
votes
2answers
144 views
Why do we use the terms AC and DC if they have nothing to do with current?
It seems archaic, maybe that we use the term AC (alternating current) and DC (direct current) to talk about power systems. After all, it is the voltage waveform we're usually referring to. In my first ...
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4answers
99 views
Possibly unstable output of linear power supply due to very large current amplfication
I'm designing a linear power supply with an op-amp as error amp and a Sziklai pair as output stage as a hobby project (see schematic below).
I'm worried, that the output Vo will be unstable/...
0
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1answer
57 views
Power controlling a soldering iron
I have used a single rectifying diode to lower power of 60W Chinese soldering iron due to overheating.
Though I am pleased with the result, I still plan to have variable power output for heavy ...
2
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1answer
51 views
Regenerative Load Circuit
In a recent question it was asked whether a boost converter could be used to "recycle" power output by a buck converter being tested. There are quite a few commercial regenerative electronic ...
3
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4answers
479 views
How can I verify the max power theorem in a buffer opamp?
I was thinking since the buffer makes the output follow the input the power should be the same in a buffer opamp circuit and a resistive load.
There is the next circuit (the expected power was .5W, ...
0
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0answers
47 views
Need help in Latching ON/OFF switch
I am working on a latching on/off switch, There are many ways to do it by using discrete components. But I want to use an IC to perform that task. I found MAX16054 IC which is similar to my ...
0
votes
1answer
27 views
RGB LED matrix 64x32 + ESP32 powering
I'm trying to figure out what's the best way to power a 64x32 RGB LED matrix and an ESP32 WROOM 32D using both a power bank (some 18650 2000mAh 3.7V in parallel + voltage regulator) and USB C (5V 3A). ...
