Newest Questions
207,389 questions
4
votes
3
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RS-485 Transmission problem (Modbus RTU)
EDIT: Problem was solved.
The baudrate from the moxa board had a mismatch of 5%, preventing proper transmission. The problem is not electrical but driver related, since by using termios and ioctl to ...
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-4
votes
4
answers
156
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What have I done wrong?
I have this circuit to do in the simulation but it shows that everything is 0 when I run the simulation. Is there anything I have done wrong?
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1
vote
1
answer
49
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Modelling vacuum circuit breaker in LTSpice
Typically, when simulating power system transients, engineers use ETMP and/or ATP. I have many transformer models in LTSpice and this software have many features that makes my life much easier when ...
- 1,495
0
votes
1
answer
51
views
Can I move the ground and neutral to the main service disconnect panel? [closed]
We have a new 200 amp service, with a new meter box and service disconnect on the exterior of the house. Directly behind the meter box is a new larger 40 spot sub-panel.
We want to install a generator ...
- 11
0
votes
1
answer
33
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RF matching circuit on SIM7600 module - components type
Do these components (SMD resistors and capacitors) used for matching need to be RF components (for example - Vishay RF resistor), or can they be standard ones?
Source for schematic: https://edworks....
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0
votes
0
answers
53
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ESP32 to 16 analog inputs from CT sensors and 16 outputs to a relay module
I have the following three items I need to connect together. It has been a long time since I have worked with electronics and I figured I would ask for suggestions on what kind of interconnect would ...
- 159
0
votes
3
answers
81
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Is it necessary to store the stack pointer when context switching due to interrupts?
When an interrupt occurs, the current program context is pushed onto the stack and the interrupt starts running. After the interrupt finishes its execution, the hardware knows how many addresses to ...
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0
votes
0
answers
21
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Invalid MIG when booting using kcu105 board
Vivado version: 2023.1
Board: KCU105 evaluation board
I am getting the following message when booting from the configuration memory:
I am trying to connect the KCU105 evaluation board to the PCIe slot ...
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0
votes
2
answers
52
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Minimum resonant capacitance value that meets voltage limits
I am working on a question dealing with series resonant converters. I am simulating it in PLECS. The circuit diagram is below:
The question is the find the minimum resonant capacitor value (\$ C_{res}...
0
votes
0
answers
43
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Issue with i2c bus on my ESP32, cannot write or read data anymore
I am working on my own PCB with an ESPWROOM32. I an using one of the 2 I2C bus to communicate with 2 digital potentiometers AD5245BRJZ5-RL7, here there datasheets : datasheet_potentiometers, and one ...
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-1
votes
1
answer
52
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Can I connect two regulated power sources in series to obtain a dual power supply?
I am building two 12V regulated power supplies with LM7812. I am using a single transformer and have chosen to draw the circuits indepemdent from one another. I, however, would like to have the option ...
0
votes
5
answers
128
views
Is it OK to read a digital input as an ADC value?
In my project, I am using a PIC18F67K40 microcontroller (datasheet: URL) from Microchip. The input voltage is 3.3 V.
The microcontroller has a digital input to detect contact between two metallic ...
- 441
0
votes
4
answers
69
views
24V Input 24V LED Voltage
My input voltage is 24V DC. I am trying to drive a LED array which has 8 LEDs with 3V forward voltage. It means that 24V input and 24V LED voltage. I cannot use Buck or Boost Driver to maintain the 3A ...
0
votes
1
answer
96
views
Would long distance Franklin Bells work?
Ever since I heard about the Oxford Electric Bell Experiment which uses Franklin Bells, I found myself curious about whether this could be applied on a larger scale. For instance would it be possible ...
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1
vote
0
answers
108
views
What is the purpose of Sziklai pair here? [closed]
I'm confused as to why this circuit uses Sziklai pairs that are meant for huge current gain if most of the amplified current at output - the emitter of NPN resistor gets drained through 2.2k ohm ...
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1
vote
1
answer
79
views
Is bootstrapping required for this bridge configuration?
Is this diagram practical for driving the high-side MOSFET?
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5
votes
3
answers
386
views
Does a magnetic transducer buzzer need a resistor in series?
I am designing a circuit for a magnetic transducer buzzer and this is the provided application schematic for the buzzer I am using (ST-025BH):
The buzzers maximum mean current is 100mA, and with its ...
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3
votes
2
answers
282
views
How to properly design a circuit for an analog sensor?
I have an analog sensor that requires constant supply voltage and outputs a fraction of the supply voltage. I need to design a module that will be able to output a digital signal representing the ...
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4
votes
3
answers
989
views
How do I keep a sine wave input after passing it through a filter?
I designed this schematic:
The input is a sinewave of RMS 12.5mV. I pass it through a 2nd order high-pass filter of cutoff frequency 2kHz, and then through a non-inverting op-amp.
The gain of the ...
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2
votes
2
answers
458
views
SSD OLED Turn On via I2C
I am trying to use I2C to switch on a OLED display using a minimal number of instructions.
I noticed in this blog they claim that there is a fairly long initialization sequence necessary before it's ...
- 351
1
vote
1
answer
133
views
Efficient rectifier for bike dynamo, LM74670
The question is relative to bike dynamo (actually an alternator) rectifying, the main goal being to minimize power loss. The system being mounted on a bicycle, space and weight are also a concern (so ...
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1
vote
1
answer
49
views
Please Identify these Components with Markings
Please help me to identify this IC & diode.
The top marking of ic is "H134" with SOT-23-5 package. and diode marking is " 05W ".
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2
votes
1
answer
73
views
Component search for dead TV
I am looking for a component of my dead TV.
It is IC207 in the picture and the
TV is a GU55AU7179U and the board no is BN9653076A.
Does anyone have an idea what chip this is? Most probably a voltage ...
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0
votes
0
answers
34
views
How to simulate a forced shutdown of a high-inertia motor to test voltage spikes and surges introduced in the system?
I am working on a test system to simulate the behavior of a motor with high inertia when subjected to a forced shutdown, generating voltage spikes that could affect the connected power supply and ...
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2
votes
1
answer
191
views
How can ceramic input capacitors cause overvoltage transients?
I was going through this article from Analog devices.This document mentions voltage transients in ceramic capacitors. This is given below.
This does not explain why transients are produced in ...
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0
votes
1
answer
81
views
Simple op amp circuit not following simulation
I came up with a simple circuit to level shift and boost current (see attached image). The idea is that I use a dac to convert digital signals from a microcontroller to 0-5 volts and then level shift ...
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1
vote
0
answers
34
views
Phase current of a brushless motor
I am using a TI microcontroller with the BOOSTXL-3PHGANINV driver.
I'm running a sensorless brushless motor using FOC.
Looking at the schematic of the BOOSTXL-3PHGANINV, an INA240A1 produces on one of ...
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-1
votes
0
answers
50
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Why DSSS is not used in IoT application? (comparing DSSS and CSS)
I wonder why DSSS is not used in IoT applications.
I asked it from ChatGPT and its answer summary is this:
CSS is better suited for IoT applications because it offers:
...
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-2
votes
0
answers
38
views
Off grid TV with drill battery [closed]
I found a Phillips Magnavox 15" monitor/TV at salvation army for $5. What caught my attention was the AC adapter its power supply.
I've been off grid over 10 years so with no formal education &...
7
votes
9
answers
2k
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How can I control LED brightness from an MCU without using PWM
I want to turn 4 LEDs off, on, or anywhere in between with an MCU. I do not want to use PWM because I have to avoid flicker on camera.
I have a DAC on the MCU that can output between 0 and 2.8V, and a ...
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2
votes
2
answers
118
views
Why electronics are cheaper on big Chinese platforms? [closed]
Let's say I want a TTL to RS485 converter. I can go on a famous Chinese platform and obtain a board for $1-$2. This board's main component is MAX485.
I can obtain this IC for $5 or so on usual sites: ...
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2
votes
0
answers
82
views
Could Not Perform Circuit Analysis
I'm posting this problem again from University of Houstan to study, and I'm clearly new with this. So I didn't know how to post pictures more than one to show my solution. I tried this problem using ...
2
votes
1
answer
68
views
Can I run an axial fan with a stated max voltage of 27.6 V off the 24V supply in a truck?
Most sources online state that a truck alternator (24 V system) has an output voltage of 27.6-28.8 V. All of the 24 V axial fan options I can find on Mouser/Digikey state a max input voltage of 27.6 V....
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0
votes
0
answers
4
views
Should the R Pi Compute Module 5 LED_nACT pin be on the anode or cathode of an LED? [migrated]
Im designing a carrier board for the Raspberry Pi Compute Module 5 for a project and I'm connecting a green LED to the LED_nACT pin for debugging. The only description of the pin in the docs is this:
&...
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2
votes
1
answer
62
views
Why is my lowpass filter starting out negative after going through a second amplification stage when its a non-inverting amplifier?
I'm building a wireless speaker and after passing the first stage of active filters everything is normal and behaves as expected. However when trying to amplify the signal even more to match the ...
-1
votes
0
answers
39
views
How to decrease charging voltage of inverter+charger combo [closed]
I have a brand new 12DC to 220VAC modified sine-wave inverter charger combo device. It works much like a UPS; it passes through the mains AC to the load and keeps the SLA battery charged when the ...
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3
votes
1
answer
77
views
RF trace at 4 layer PCB with over-the-metal chip antenna
I'm designing a PCB with 2.4GHz chip antenna and hope RF engineers can give me some clarification with RF design.
My PCB has 0201 size components and this highly constrains what RF trace I can use.
...
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0
votes
0
answers
14
views
extend mipi d-phy using new chip [closed]
Hello EE Forum -
We are looking to extend our MIPI D/PHY signal beyond 30 mm without adding a re-driver and one of my co-workers has found this product, https://www.silicon-line.com/sl84603/, SL84603 (...
0
votes
0
answers
31
views
Electric Motor Maximum RPM [closed]
ive been using an electric motor and it reach the maximum voltage output of the motor at around 4000 RPM, and as i expect the back emf got larger and since it already reach the maximum voltage output, ...
2
votes
1
answer
86
views
Simulation vs Reality in MOSFET circuit
First of all, here's some background about the involved hardware (all custom designed PCBs).
Background
There's a Master Board (MB) and there are Slave Boards (SB).
The SBs are to be connected to the ...
- 3,008
0
votes
0
answers
36
views
Li-ion Batteries & Exposure to Microwaves [closed]
I'm doing research on a condition when Li-ion batteries are exposed to microwaves. I've seen instances when battery read out go from fully charged to zero rapidly. My understanding is that microwaves ...
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1
vote
1
answer
44
views
Can I put the input negative and output negative both on the same ground in a voltage converter?
I'm making a PCB that's powered with a 48V battery, some components require 5V, and obviously for this case I need a step down component. Unfortenately, the component is out of stock currently, as I ...
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-2
votes
0
answers
47
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Identify component request [closed]
I need your help in identifying this component. It is part of DC-DC buck converter circuit.
-1
votes
0
answers
15
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Backscattering IMU sensor data using Bluetooth [closed]
these are two quick videos describing what the title means:
https://www.youtube.com/watch?v=J8e8UIv9Pws
https://www.youtube.com/watch?v=_Ze3HAOzWCw&t=678s (skip to 11:18)
Essentially, I just want ...
3
votes
2
answers
176
views
Is AC/DC Analysis Just an Application of Superposition Theorem?
I’ve been diving into circuit analysis and came across a thought that I wanted to share and get your opinions on.
When performing AC and DC analysis in circuits, it seems to me that we’re essentially ...
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0
votes
0
answers
76
views
What IC is this which is part of a wireless camera [closed]
I have this IC that's part of a wireless camera for a Drone. I've identified different ICs, but I'm not yet able to get any details about this.
Where I can find a datasheet for it?
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1
vote
1
answer
42
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What is the mathematical relationship between substrate doping and the threshold voltage \$V_{th}\$?
I am trying to understand the mathematical relationship between substrate doping \$N_A\$ and the threshold voltage \$V_{th}\$ of a MOSFET. When \$V_{BS}=0\$ the threshold voltage \$V_{th}\$ is ...
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0
votes
1
answer
38
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Modifying SBZK07 Buck Converter to Control Output Voltage with ESP32 and DAC MCP4725
I am working on modifying an SBZK07 DC-DC step-down buck converter to dynamically control its output voltage using an ESP32. My goal is to achieve an adjustable output range of 0-15V. OpAmps and ...
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0
votes
0
answers
33
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Help Identifying Display on Anycubic TFT V0.0.2
I’m working with a TFT display that came with a board labeled Anycubic TFT V0.0.2, which includes an STM32F103 microcontroller and a TC58BVG1S3HTA00 flash memory chip. The display has 45 pins in total ...
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-1
votes
2
answers
41
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Contradiction in Deriving Closed-Loop Gain of Op Amps [duplicate]
I'm going through the derivations for finding the closed-loop gain of a non-inverting and inverting op amp using the virtual ground method. One thing that this assumes to help simplify the math is ...
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