Newest Questions
213,014 questions
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Op amp open loop schematic
i found this schematic for op amp open loop how this is an open loop can anyone explain it to me? Most of the textbooks have the open loop without feedback then i am confused how this schematic is ...
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1
answer
21
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How to design a 5th-order passive RC low-pass filter (500 kHz cutoff) in LTspice?
I am trying to simulate a 5th-order passive RC low-pass filter in LTspice.
My requirements:
Cutoff frequency: 500 kHz
Input frequency range: 30 kHz – 500 kHz
Signal amplitude: 1.5 V p-p
Only R and C ...
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0
answers
17
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Why rectifier of series resonant dc–dc converter is driven by sunusoidal voltage and not current and visevarsa for parallel resonant one?
In the Fundamentals of Power Electronics book by Dragan Maksimović and Erickson, series and parallel resonant DC–DC converters are drawn as follows, respectively:
The book states that in the series ...
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1
answer
43
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Do I need a bulk capacitor for a 30A 4S drone ESC?
I am designing a 3-phase BLDC ESC for a quadcopter drone powered by a 4S LiPo battery (VDD = 16.8V). My design uses an STM32F103C8T6 MCU, UCC27712QDRQ1 gate drivers, and AGM403AP N-channel MOSFETs. In ...
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1
answer
43
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How to calculate multiple pulses in pulsed power system?
I want to calculate how many joules 3 pulses per second lasting 0.5 seconds of 3000 watts in an electric motor would consume compared to a 3000 watt electric motor running continuously for 1 second, ...
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39
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AM modulation in multisim doesn't work
Hello, I already asked a question about this circuit. Unfortunately, I still haven't been able to get AM modulation working with it. Although other circuits I've been shown work.
I still want to find ...
2
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44
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MIL-STD-1275 Protection Method
I have a few questions about MIL-STD-1275 and would like to discuss them with you.
Wouldn’t the combination of a TVS diode at the input and a Schottky diode afterward be sufficient to suppress ...
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2
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2
answers
188
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BC547 datasheet, what is this graph used for?
I have recently started studying BJTs with an hands-on approach.
I am trying to make a simple switch by working in the cut-off and saturation regions and, while the equations seem quite clear to me ...
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1
answer
40
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LTC4418 for prioritizing 5 power sources
I’m working on a project where I need to prioritize 5 power sources, all providing 28 V DC. The switching between sources must be fast (<50 ms), and I was thinking of using the LTC4418 since it ...
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57
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Spilling coffee over USB keyboard [closed]
There is this movie trope where someone spills their coffee over their pc keyboard and the whole machine shuts down with permanent damage.
On a laptop that isn't optimized for it this might seem ...
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5
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86
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Cut-Off Frequency vs. Resonant Frequency in LC Circuits — What’s the Real Difference?
I’m trying to clearly understand the difference between cut-off frequency and resonant frequency in the context of LC circuits.
When I look up the formulas, both frequencies seem to use the same ...
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2
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70
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Op-amp inverting amplifier
I tried building an op-amp inverting amplifier in Multisim, but the signal in the output node is not inverted. Can anyone help me figure out what is the issue?
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1
vote
2
answers
158
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How precise is a DVM input impedance for high-Z circuit measurements?
I'm building a resistive probe using four 10 megaohms resistors to measure the output of a high impedance (> 2Meg)/high voltage bias supply without loading it too much. The idea is that the jury-...
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2
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83
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Gate driver bias from high voltage
I am making a forward converter and on the high side the voltage is 320 V. However I need to bias a gate driver that needs 17 V and needs to provide 1 amp to the MOSFETs. I am stuck in a situation ...
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1
answer
98
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Run AC mains fairy light using phone charger and USB cable [closed]
I have this fairy light which I want to understand better and redesign. The original strip accepted "12V-240V 50/60 HZ" input (as per its cover using the white 2-pin plug. I opened the box, ...
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81
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Describing an audio processing circuit fault [closed]
How could I describe an audio processing circuit fault to a circuit designer where the following symptoms occur:
After a period of silence in the recording, the first segment of audio is missing/...
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1
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2
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146
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Foldback Current Limiting Voltage Divider
I want to learn how foldback current limiting works. I found this website :
https://www.eeeguide.com/foldback-current-limiting-circuit/
Which has the following picture :
And I tried to replicate it ...
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0
answers
48
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Advice needed: Low-power mobile uplink detection system design (RF beginner) [closed]
For a university project, I am trying to design a system capable of locating uplink signals emitted by mobile phones.
The Constraints: I need to scan different frequency bands corresponding to various ...
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63
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Open Energy Monitor, will my changes work to have it monitor 480V 3 phase?
So I'm working on making a variant of the 3 Phase Open Energy Monitor and a data logger based on the same.
I aim to use something based on these to watch 3 phase spindles and servos on CNC machines to ...
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0
answers
90
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What are there in real world transmission lines? [closed]
I have a project where I need to qualitatively calculate the effect of renewable energy sources in a grid. Since the renewable sources are added in medium voltage (20kV) excess power provided is ...
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1
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0
answers
110
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Help me find the value of the crystal oscillator
I have this 2-pin crystal oscillator with possible marking "H1 3937", connected to two load capacitors. Can anyone help me find the frequency value of the oscillator?
The adjacent U10 is an ...
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votes
1
answer
53
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Magjack burned way to bypass it? [closed]
I’m having an issue with a server whose management port has burned out. This RJ45 port is a 12-pin MagJack (1G)
I absolutely need it to access the management interface.
I’ve desoldered the RJ45 ...
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4
answers
108
views
High speed signals and control impedance traces
What exactly is the definition of a high speed signal? Would you consider a signal of 1 MHz a high frequency signal? Or does it depend on the rise and fall time (the edges are what create harmonics)?
...
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3
votes
1
answer
318
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Full-bridge rectifier causes strange slow oscillation of the DC voltage envelope
I was asked to repair a Phywe laboratory voltage source that exhibited small, periodic oscillations of its output voltage. This unit is a very simple passive supply: an autotransformer feeding a heavy-...
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0
answers
25
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Unexpected ADC Voltage on Idle Channels in an STM32-Based Multi-Charger Current Sensing Circuit
I have mounted 4 mobile charger modules, which are switching power supplies, onto a single PCB. In my circuit, I’m also using an STM32 microcontroller, and I have enabled 4 ADC channels to read ...
1
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2
answers
87
views
How to find the output resistance of a Transconductance Amplifier in LTspice?
Here is a circuit I made in LTspice based on an example in the Sedra/Smith book. I want to measure Rout and Rof (as shown in the Example's figure) if possible. How should I do this?
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2
answers
100
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Blank Audio using LM393
This is a Tone audio generator. The 4046 generates a tone and TL074 controls its threshold audio.
Please consider the LM393 schematic, its output is 0 or -5V. I want to connect the LM393 to this audio ...
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votes
2
answers
73
views
How to Calculate flyback transformer primary and secondary number of turns and turn ratio?
I try to design SMPS converter with flyback converter topology.
I can find right value of flyback transformer. For CCM, what is the equation for calculating primary and secondary number of turns & ...
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2
answers
121
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Why don't 5-pin DIN MIDI In connectors provide power on pins 1 and 3?
From the MIDI Spec 1.0:
I looked around briefly and cannot find this discussed at all.
I remember when MIDI was first introduces in the 1980s. I understand the electrical specifications, the opto-...
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votes
3
answers
434
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Will this this schematic modification work?
newbie here trying to learn and create an electronics project for my uni (Comp E)
My goal here is to create a DIY infrared sensor using photodiode and IR transmitter, and read the signal through a MCU ...
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0
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59
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CP2102 not detected in Windows on custom PCB
I have a custom PCB with CP2102 but it seems like windows doesn't detect the CP2102. Here is the schematic and the PCB. I also measured the voltage of the pins:
REGIN: 5 V
VDD: 3.3 V
VBUS: 5 V
D+: 2....
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2
answers
78
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PLCC-32 to DIP-32 adapter: how to connect chip to socket?
I'm trying to make a 3.3V breadboard computer, and didn't find good DIP ROM/flash chips, so I decided to buy 2 Microchip SST39VF010-70-4C-NHEs, which are PLCC-32 chips, and a Chip Quik / Prototype ...
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2
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444
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Can a magnetic loop antenna be used to communicate through a perfect metal container?
I understand that in the near field of a loop antenna the magnetic field dominates, before it has formed a radiative propagating EM wave. Based on this, and the fact that magnetic fields can penetrate ...
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2
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2
answers
133
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What are the sources of noise for electricity in a power grid?
What are the sources of noise for electricity in a power grid?
Is noise picked picked up in transmission lines, transformer stations, or elsewhere, or is noise primarily do how the power is generated?
...
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2
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101
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Is AC from a DC→AC inverter less noisy than that from the grid?
Is the AC from a DC→AC inverter less noisy than the AC from the power grid?
I'm wondering if residential solar energy is "cleaner" in the sense of less noisy than that from the power grid.
...
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1
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0
answers
64
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Frequency response injection amplitude determination and meaning of large signal response
When extracting the loop gain frequency of a nonlinear system:
• What is a good way to ensure the disturbance injection sinusoid amplitude is small enough such that the response remains in a ...
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4
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3
answers
247
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Low-Side Current Sense Simulation
I have followed design guides online on how to create a low-side current sense circuit, for use with FOC to control a 3-phase BLDC.
There is a differential input low-pass filter, common-mode filter, ...
1
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2
answers
78
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Confused with a DPST mains switch
I'm planning to use a DPST rocker switch as follows:
To be more explicit I want to use the switch as follows:
Both wires to the DPST SW above will be line wires not neutral. The switch is from here ...
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0
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48
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How to wire multiple laser controllers if one has a single interlock mechanism
My background is in optical engineering, and I have limited knowledge of electronics.
I have a microscope that has an interlock for the eyepiece. There's a button on the microscope to toggle between ...
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0
answers
64
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Making a multivibrator circuit using LM741 [closed]
The green LED at the output of the steady-state circuit turns off after 52 ms when a button is pressed, and then the red LED turns on. When the button is released, the red LED turns off after 2 ...
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0
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35
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Ordering of the parallel capacitors in LC-filter used with Pololu U3V40F5 step-up converter
I'm using Pololu U3V40F5 step-up converter consuming from 3,7V Lithium ion battery to power Raspberry Pi Zero 2W (consumes up to 2,5A at 5V). The Raspberry gives away analog video and I'm facing ...
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1
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65
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Boost Converter Not Giving Output When I Put MOSFET on Both VIN and EN
Problem Description (Simple Explanation):
I am using an MT3608 boost converter (3.7–4.2V battery → 5V).
I want the boost to turn OFF completely when my BUCK +5.2V supply is present.
So I used a P-...
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1
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63
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Need Help Validating NEMA 17 Stepper Circuit for Portable Wind Turbine (AC to 5V USB)
I'm a senior in high school working on creating a portable and modular wind turbine. It's not innovative, but we'll be using it to help vulnerable communities utilize pre-typhoon (pre-hurricane) winds ...
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0
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48
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Battery charging and load sharing circuit
Continuing from my previous question in the link (Lipo battery charging circuit), Based on the suggestions, I’ve tried modifying the circuit to add load-sharing capability, using a few reference ...
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3
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131
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Bandpass Filter for Class D Amplifier
I have a Class D amplifier that requires the use of a bandpass filter to ensure my speaker only receives signals between 100 Hz and 4 kHz, as per the question asked at Building a Bandpass Filter for a ...
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0
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64
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Need direction for my academic path [closed]
35 yrs exp. carpenter here. Basic understanding of electricity. I want to enter the renewable energy field. Which major should I pick first for an online college? I have a business that will be sold ...
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1
answer
90
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Control Loop response of Buck Converters - Why?
In buck converters, control loop analysis involves injecting a small AC signal into the output feedback path to assess how the loop responds. This method helps evaluate the stability and dynamic ...
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1
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91
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STM32 PCB Review 4-layer
This is my first PCB and I just wanted a review or maybe some tips. Its a STM32 PCB with a USB connection and Micro SD card slot. Its a 4 layer with a SGGS stackup. I was just looking for a review or ...
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1
answer
79
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Designing a Control Board to Run a Drum Sander [closed]
I am attempting to repair a control board for a tool at work. Unfortunately I can not identify the exact component that has failed. The replacement board is $600 and more than 10 years old.
My thought ...
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0
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47
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Does STM32H573 support a non-LL HAL for non-octo SPI slave mode?
The STM32H573 SDK includes two HALs: LL and HAL.
I could find only one example using the non-octo SPI in slave mode, but it uses the LL HAL, stm32h5xx_ll_spi.h. Is there a non-LL HAL for non-octo SPI ...
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