text stringlengths 83 79.5k |
|---|
H: Identifying a connector
Can anyone identify this connector?
Female part:
The crimp parts look like this:
And the male part looks like this:
Context:
These came with a Smoothieboard v1.1. I keep messing up the crimp connections, so I want to order some spare connectors. The documentation does not seems to iden... |
H: Ideal opamp closed loop problem
The inverting circuit with the T network in the feedback
is redrawn in Fig. P2.30 in a way that emphasizes the
observation that R2 and R3 in effect are in parallel (because
the ideal op amp forces a virtual ground at the inverting
input terminal). Use this observation to derive an ex... |
H: Tube amplifier preamplifier
I received this little two tube preamp
http://www.gikfun.com/electronic-diy-kits-c-7/6j1-tube-preamplifier-board-20-stereo-multiple-diy-kit-p-730.html
It comes with 9 470uF caps. The symbol on the board for them is a circle, with white strips across one of the legs. Does anyone know if t... |
H: Atmega328 AU has a low Voltage output pin
For a project I am programming an Atmega 328 AU on a custom made PCB. After a lot of struggles I managed to get a bootloader and a program on the chip. I programmed some IO pins and they seem to work fine. The output pins that I use give: LOW = 0 Volt High = 5 Volt which is... |
H: How to be sure that a ceramic capacitor can manage a RMS current?
I'm in the middle of a design and I need a capacitor of:
10µF
Rated at 10V
Has to handle a ripple current of 250mA RMS, at 400kHz
Most electrolytic capacitor data sheets give a maximum RMS value for the current. However, I would rather use a cerami... |
H: ADC input filter design for DC input signal
My plan is to use an ADS1115 ADC to read a low impedance 0-5V output signal from a level transducer. The ADC data sheet gives guidance for ADC input filtering. This data sheet, and even other input filter design notes all assume a relatively high frequency input signal (H... |
H: Does the "electricity saving box" work?
https://electrical-engineering-portal.com/the-real-truth-behind-household-power-savers
concludes
Power factor correction devices improve power quality but do not
generally improve energy efficiency (meaning they would not reduce
your energy bill). There are several reasons w... |
H: What is a unipolar inductor?
Can somebody explain what a 'Unipolar Inductor' is? I'm trying to understand the process by which the rotational energy of a black hole is converted into energy to power relativistic jets.
In the book I read (https://1lib.eu/book/2339827/854387 [pages 157, 158, 159]) it is said that th... |
H: Modifying an irregular length bit field in a register in C/C++
Suppose I wanted to modify the field ADD[7:0] in the following register:
I wrote this to make things more convenient.
{
const uint8_t Character = USART_TERMINATION_CHAR; //8-bit ASCII termination character
//masks to modify register
... |
H: Firmware not embedded on the device?
Recently reading about Linux and its folder /lib/firmware, I read that firmware is not needed to "live" on the device, that some network devices dont have any ROM to store a firmware. How is this possible if its definition is that is software that is present on the device and it... |
H: Can't secure supply of 32mhz Automotive grade oscillator - why is this?
This is my first automotive PCB. I designed in a high temp crystal from Digikey. Stock then went to 0 with big lead times, and then my alternate went EOL. I then spun the board with a TCXO. All three parts I had picked went to 0 stock. I then s... |
H: What is beam coupling coefficient for linear beam klystron?
What does beam coupling coefficient exactly tell? For eg. a voltage gain coefficient tells how much times the input was amplified. So what does beam coupling coefficient tell, like does it tell how much the beam is coupled with something?
AI: In a linear b... |
H: Arduino resetting or malfunctioning when controlling 48V DC motors with relay module
I'm building an Arduino controlled crane machine out of old crane machine parts.
The motors in a crane machine are 48V DC and I am controlling them with an H-bridge configuration using an 8 channel relay module I got off eBay which... |
H: VBUS Pin on USB Communication
I have been eyeing USB communication in microcontrollers especially the dspic33 series. Now, when I looking over the physical connector of the USB, I came to know that there are 5 pins used.
VBUS,D+,D-,GND,USB ID pins. In these 5, I got little confusion about the VBUS pin. As per the d... |
H: Assigning binary value to decimal value using counter
I don't know muach about verilog, but i started to study it lately. So if these codes doesn't make sense at all, forgive me :D
I am writing a verilog code for Sinus lookup table.
for instance,
'd1 <= 16'b0000000000010001;
'd2 <= 16'b0000000000100011;
'd3 <= 16'b... |
H: Why does a pure resistance have an imaginary current and voltage?
While solving the below circuit:
The solution is as shown below:
I noticed the following while analyzing it:
Why does the voltage across a pure resistance and the current through it have imaginary parts?
What do these imaginary parts represent?
... |
H: Do you know the name of this item for crimping two cables?
I just need the name of this component.
AI: They are specifically known as U-joint crimps. The cables are overlapped into a U-shaped peice of metal, which is then crushed around them.
Butt crimps do a similar job, except there are two crimping points with t... |
H: How to short certain pins on a 7x9 array
I’m planning to control an 80s electric typewriter via a Raspberry Pi. I want to emulate the keyboard matrix by shorting one of seven 5V pins to another one of nine that feed into a microcontroller. Eg, shorting pin 0 and 16 prints out a full stop; 5 and 12 print ‘w’ etc.
H... |
H: Buffer amplifier and input impedance
It is said that the input impedance of a buffer must be high enough so that it can isolate its input voltage and carry it to its output for driving purposes.
What I do not understand is why we treat all the independent sources as shorts while calculating input impedance. I know ... |
H: Power measurement on multiple loads
I'm designing a circuit for driving multiple loads (min. 16, up to 64) like the one shown below
simulate this circuit – Schematic created using CircuitLab
The input source is from a multi-channel DAC driven by an ATMega-like uC that can range from 0 to 5 V, and it should be able... |
H: FET source body connected to the same potential
I have learn that the FET looks like this:
However industrial FETs are not built like that.The source and the substrate have common potential.However if the source and substrate have common potential that means the conductive channel formed is not wide enough to conn... |
H: How to improve the accuracy of measured ADC voltage in a circuit connected to Vcc
The question is based on the following setup.
As depicted there is an IC to measure the real value of the 3.3V supply voltage accurately. The measured value of the 3.3V source is transferred via SPI to the microcontroller. This microc... |
H: With Bluetooth turned off in PC settings, do keyboards and mice still emit radiation?
Do you know if a wireless mouse emits radiation in wired mode? Using the USB cable, With Bluetooth turned off, but with the switch set to "On"?
And also do you know if a wireless keyboard, also with Bluetooth turned off, emits rad... |
H: How to protect the circuit from Ethernet ESD, overvoltage, etc
Creating a carrier board for a RPI Compute Module4, I am not sure how to protect the circuitry from possible ESD /over-voltage coming through Ethernet connector.
In normal circumstances, I would apply some zener diode and in-serie resistors, but I don't... |
H: Overvoltage protection develops heat, is ok?
considering my old question: Here, i've made the following circuit using equivalent components on SMD, here is the schematic:
And these are the parts that i've picked from LCSC:
Fuse: Link here
Zener diode: Link here
Resistor: Link here
Transistor: Link here
The circu... |
H: What are the different types of digital signals
In a digital logic class I was taught that a digital signal is one whose y-component, voltage, is discretized but whose time domain is continuous. In a signal processing class, we worked with digital signals that may have 8 bits of discrete voltage values, but were al... |
H: How to drive a relay from a MOSFET/IRF?
simulate this circuit – Schematic created using CircuitLab
Hello,
I would drive a machine to pilot its ON/OFF status.
So in idea it should be OK but is it?
What requires attention or this is an error in concept?
Regards
AI: That (IRF9530) is a P channel mosfet. But you have... |
H: Binary division restoring method
Hi i need help in understanding the binary division restoring method
From -2, we stored the value to 5 by adding the divisor which is 7
After adding 7 to get 5, why does it automatically jump to 10?
So from 5-7 = -2, restore -2+7=5 => 10-7=3
Where does this 10 from, and can anyone e... |
H: What type of oscilloscope can be used to troubleshoot 100BASE-T1 automotive ethernet?
I would like to implement the 100Mbps single pair automotive ethernet specified in 802.3bw, otherwise known as 100BASE-T1. I was told that in order to troubleshoot and test on this standard, the scope must be capable of 1 Ghz. I... |
H: Why is my loudspeaker not working? From Make: Electronics
I am a complete beginner in the world of electronics and I am following the amazing book by Charles Platt, Make: Electronics (second edition). I am stuck at Experiment 11, when I need to connect an oscillator to a loudspeaker.
The picture shows the circuit ... |
H: Will Kirchoff's voltage law work in a vacuum
Kirchoff's voltage rule tells us that the sum of voltages around a closed loop in a circuit will equal zero.
If a battery sits on a table, using KVL and treating air as matter with high resistance makes a KVL loop with a voltage gain of the battery's voltage which gets l... |
H: Examples of using a circular polarizer filter for LED display
I was looking for ways to increase the contrast of a LED-based seven-segment display like this against indoor ambient light, and found this comment on EEVblog suggesting using circular polarizing filters. The basic idea is that
when circularly polarised... |
H: How slowly can you clock an AT25DF641A SPI Flash?
I am have started to try to use a SPI Flash. To better understand how it works, I decided to try to bit bang it with the GPIO on a Raspberry Pi. Everything seems correct, but I do not seem to have any output from the SPI Flash. The clock signal I am sending it is... |
H: PC ATX12VO (12V only) standard - Why does everybody say it has higher efficiency?
To my understandings, the new 12-volt only standard moves the 5V and 3.3V supplies off from the ATX power supply "box" to the motherboard.
According to PC World (which is cited by Wikipedia), Gamers Nexus, and Linus Tech Tips, the new... |
H: Feed-through termination
I have a very basic question about rf-electronics: I tried to understand how feed-through terminators work, but I could not find a wiring diagram online.
Intuitively it would make sense to me if such a feed-through terminator is equivalent to a t-piece with a termination at one end of it, e... |
H: 555 Timer won't run at calculated frequency
I have a 555 timer connected to an LED that I am trying to strobe for 450ms on, 72ms off to replicate an existing strobe light I have. The issue I am having is it is strobing at around 243ms on, 42ms off. According to my calculations, in order to get that timing I would n... |
H: p-channel and n-channel MOSFET small signal models
What is the difference between the p-channel and n-channel MOSFET small signal models? Is there a difference?
AI: The only difference in a given model is that signs for voltages and currents are changed as appropriate.
There are differences in the actual devices th... |
H: Square wave, triangle wave etc. not defined in International Electrotechnical Vocabulary (IEV.) Are they not standard terminology?
Why are there no definitions for typical terms like square wave, triangle wave etc. in the International Electrotechnical Vocabulary (IEV)?
Are these widely used descriptions not define... |
H: What equation should I use to calculate inductance of wire coil?
I've been working on a project recently which requires me to build an inductor, however in my research I found many different equations (with a range of variables used and giving very different results to the same coil specifications) and I was wonder... |
H: MOSFET Selection criteria considering conduction losses, switching losses and working frequency
I am trying to choose a suitable MOSFET for my full-bridge resonant converter for wireless power transfer. The circuit topology is something like the following. Specifications: rated power \$-~500 W\$, DC supply \$-~50... |
H: Boost converter extremely low efficiency
I'm trying to use a boost converter from Pololu that steps up my 1.25 input voltage from a AAA battery to 5V in order to power an Arduino. I have found that my Arduino needs .03A to be powered.
I understand that if the boost converter were 100% efficient and when using (V*I)... |
H: Can you please help identify this circular part with 2 black wires and 2 red wires?
I found this part in an old auction lot I bought. Could you please help identify what this part is?
AI: Possibly a toroidal common-mode choke in a plastic case.
Especially if it's relatively dense (ferrite core) and if red-to-red a... |
H: How do people estimate node voltage and branch current by observing a circuit?
The question might sound silly, but I hope experts can guide me on that particular issue. I am struggling for the last few months. I am a beginner in analog circuit design. When I follow a tutorial, I found that by observing a big transi... |
H: MOC3041 TRIAC Dimming Circuit
Details: I try to build the single TRIAC circuit for ON/OFF, Dimmer(600W AC Light), and AC fan Speed Control. I trying this the first time.
Problem: I using MOC3041 to control the TRIAC ON/OFF it seems to work fine but while I Tried Dimming I found using MOC3041 cant able dim the lamp ... |
H: Ungrounded laptop power brick
I'm travelling at the moment and the three-prong plug on my laptop power brick is going through a two-prong adapter and therefore losing the connection to ground.
The laptop stopped charging and I took it to a local repair place. The guy put it down to the power brick and sold me a rep... |
H: Impedance in LTspice and current plotting
I wanted to try a test simulation on LTSpice to understand few things. I have a RLC parallel circuit and I wanted to see how the impedance varies according to each one of the components (very easy but I needed to run the simulation for visualization purposes).
To my surpri... |
H: What kind of FPGA board for sha-256 algo
I am newbie in VHDL and FPGA, i was searching for an answer to my question but didn't find any good answer.
In my projet i have a .txt file containing a hexadecimal data, i want to send this data to an FPGA, 256-hash it, and then send the hashed data back to my laptop in ano... |
H: Why does a fuse voltage rating only signify the dielectric strength?
From what I understand, a typical fuse wire will melt once it's current rating is breached by some factor.
However, a fuse also has a voltage rating, which signifies its dielectric strength. From what I've read, this voltage rating means that, "be... |
H: Impedance matching L Network
I‘m trying to understand exactly what an L-section Network does. I understand it tries to eliminate the imaginary part of the impedance and match the real part. However I do not understand what excatly both components do and why the inductor(in my example, more specifically in a Highpas... |
H: Transistor maximum base breakdown voltage
In a npn transistor with 5 volts VCE and current limited to 10ma by a resistor, it needs to drive its base with a DC voltage ranging from 3 to 500 volts DC, using a base resistor of 10 K ohms the voltage in the base never exceeds 900mv, is my drive correct? In this case, ho... |
H: Why is the closed gain loop -3dB from the open loop gain rather than some other value?
I am reading the book Op Amps for Everyone and in the chapter of feedback loop theory, I have this quote (see picture) where it says in reality the closed loop gain is down by 3dB at the point X as shown below.
How does he know i... |
H: Resistor that can be placed like a jumper
I want to make a relay output to be configurable by the client as NO/NC or guarded by resistors (10k opened, 1k closed).
A solution I have been thinking about uses resistors that can be placed like a jumper on a pin header, like this:
A quick search for existence of this j... |
H: New STM32L433 pins pull high??? Damaging opamps
I have an STM32L433, fresh from RS components. I soldered it to my board. PA6 is connected to the output of an opamp - INA181A1.
There are another 2 INA opamps on the board, connected to other pins.
I have now had 2 INA181s die (actually I am not sure they died, since... |
H: Why do some microcontrollers have numerous oscillators (and what are their functions)?
Currently I am reading through the Arm based ATSAM4L series datasheet, and in the sections BSCIF and SCIF I have encountered at least 8 different oscillators/clocks (see image below). I understand that an oscillator is necessary ... |
H: Is it possible to know what is the dielectric voltage between earth and conductor of those cables?
I am looking to know what is the maximum voltage (dielectric voltage) that it can be applied between the conductors of the cable and the earth (not into the cable). Usually I look for a term which is called " Voltage ... |
H: PWM Motor Driver output voltage is enormously load - dependent
I've built this PWM motor driver (for a motor which requires 5A at maximum 24V and which I want to drive sometimes with 10V and other times at 24V). Here you find the datasheet of the mosfets.
PS: there is also a missing 10k resistance between gates an... |
H: Amplifier circuit for Bently Nevada velomitor 330525
I'm in need of measuring vibrations and I have access to these Bently Nevada velomitors.
I'm not sure how to design a ampliefier circuit for the signal.
The datasheet is says that it is a piezo electric velomitor, but what is throwing me off is that it has power ... |
H: How to safely use a transistor to control fans
I'm working on a project where I control two 12V 80mm fans with an ESP32. I've taken inspiration from various blog posts about fan control on the Raspberry Pi with a transistor (e.g. https://fizzy.cc/raspberry-pi-fan/).
As depicted in this blog post, the transistor is ... |
H: A JFET based light sensor
I am working on a LDR based JFET project which would turn on automatically when it is sufficiently dark.
Accordingly, I have designed this circuit. Is this practical? Also when the LDR value reaches 0 ohms the gate-source junction will be fully negative, but since the junction is reverse... |
H: Why voltage multiplier decreases current?
As far as understand, a voltage multiple increases the voltage but decreases current.
Can someone please explain why current decreases?
AI: A voltage multiplier has a lot of capacitors. Capacitors have impedance. The capacitors are needed to add up the voltage, but the a... |
H: Flash or EEPROM
EEPROM vs SD Flash
I am working on a Arduino program (a game, a slot machine) that needs to store 16 bitmaps (the slot machine symbols) that are 32 * 16 bytes each (total 8192 bytes). The bitmaps are static/immutable so does not need to be changed. The only requirement is that they need to be access... |
H: Treble bleed frequency cutoff
I built an attenuator for my guitar amplifier. I took the circuit from here but left out the 4 ohm toggle since my amplifiers all have 8 ohm outputs. Below is a simplified schematic of the circuit (with the L-pad set to 20 dB attenuation):
The 4.7u capacitor is supposed to be a treble... |
H: Voltage Divider returns incorrect voltage reading
I have created a simple voltage divider circuit as shown below:
Using the simulator, I can see that the voltage measures in at 0.838935V, which is expected.
However, when constructing this circuit in real life, I seem to be only reading ~0.513V on my digital multim... |
H: Op-Amp Current Consumption
I’m using the LM7321MAX operational amplifier to supply a 12V digital signal from a 5V source. For the op-amp supply voltage: is it better to use something close/equal to my output value (like 12V) or further away (like 22V)? I know the internals of an op amp are mostly BJTs so am wonderi... |
H: Can I charge my van's car battery directly from its lithium ion "house battery"?
I have a 1991 GMC van that I've converted into a poor man's RV. I've got a Yeti 1000 lithium ion house battery, and a 100 watt Renogy solar panel on the roof. When the battery has died in the past, I have hooked the ~20v solar panel ... |
H: In this circuit what is the function of this resistance in parallel with a capacitor
I understand that the capacitor produces a resistance proportional to the 50 Hz of the mains input current, in this case 220 volts
But why is that resistance installed in parallel, what function does the resistance have?
Thanks
AI... |
H: How is it that the induced EMF in an alternator is in quadrature with the main flux?
Looking at the simplified diagram of an alternator, the flux "linked" with the conductor is maximum at 90, 270 degrees, is also when induced EMF is maximum. So isn't the main flux in phase with the induced EMF, or are my assumption... |
H: Watts P.M.P.O. and audio equipment power
I am a beginner in electrical engineering, and to begin learning I decided to look into audio amplifiers.
I have seen that the power of audio amplifiers is often described in the units of watts, watts RMS, and watts PMPO.
So far, the only one of those units that I think I un... |
H: What is the purpose of RC components to ground in this class AB amplifier?
I'm talking about R6/C4. It seems like it would be filtering of some kind as the C4 will have it's voltage at the highest for DC or low frequency input, but I don't really understand the purpose.
AI: What is the purpose of RC components to g... |
H: Is there such a thing as a 'Constant Power Source'?
Academic question: Is there such a thing as an electrical constant power source, which delivers energy at a fixed rate?
Specifically ... there are voltage sources and current sources, which maintain (an approximation to) a reliable fixed voltage/current respective... |
H: Why doesn't the fan work when the LED is connected in series with it?
In this picture, I have connected a fan and an LED to a battery. The LED works when I switch the circuit ON but the fan doesn't. If I connect the fan directly, things work.
Fan not working
Fan works
What could be the reason? Is battery power th... |
H: MIC29712 in constant current mode
[EDITED] I ALSO ADDED THE LAMP TO MY DESIGN WHICH I FORGOT
I am trying to use a MIC29712 in constant current mode to draw 4A for my lamp. The power supply is 15V and can give up to 8A.
Here is the MIC29712 datasheet.
What I think I can do is this:
Since the ADJ Reference is to GND,... |
H: What is the meaning of inferred absolute zero temperature? Why does the resistance temperature graph it is obtained from behave that way?
Studying basic direct current circuits, I've come across the term inferred absolute zero temperature on computation of resistances that change due to temperature. Based on my rea... |
H: Replace LED chip with reversed polarity pin-out
I want to upgrade the LED chips of a projector.
Red: PT-120-R-C11 --> PT‐120‐RAX‐L15
Green: PT-120-G-C11 --> PT‐120‐G‐L11
Blue: PT-120-B-C11 --> PT‐120‐B‐L11
But the red LED chip (PT‐120‐RAX‐L15) has reversed polarity pin-out.
Swapping black and red cables should so... |
H: Finite input impedance of voltmeters
I have a question regarding the impedance of voltmeters. I learned that a voltmeter can be modeled as follows, where \$R1\$ is the input impedance:
simulate this circuit – Schematic created using CircuitLab
I noticed that many multimeters have a \$10\,\mathrm{M}\Omega\$ input i... |
H: Power consumption in voltage multipliers
Cockcroft–Walton generators and Marx generators are voltage multipliers. These circuits contain various diodes, capacitors and resistors that charge the capacitors in parallel and then put them in series to multiply the voltage. How much do these circuits consume?
I saw vide... |
H: Variable is not changing when one button is pressed. (String)
I couldn't decide whether this belongs in C++ or Arduino. But I guess it belongs here since it's Arduino programming.
Anyways, I'm having a hard time solving this issue. I have 4 buttons, 2 for up/down, 1 for select, and 1 for paging (Switch pages). But ... |
H: No voltage induced in secondary coil of transformer with 5V 1.5 kHz voltage from Wien bridge oscillator in primary coil
I have built a Wien bridge oscillator which outputs 5V at 1.5 kHz. When I hook up this output to the primary coil of a transformer I can't measure any voltage in the secondary coil.
Schematic:
si... |
H: How to select the correct CM choke?
Say I want to reduce noise on the data line for WS2812B led strips.
Is it a viable option to use CM chokes to reduce this noise?
According to the docs, WS2812B data speed is 800Kbs. Which I guess translates to 800Khz on the data lines.
I read cm chokes can reduce noise. But I am ... |
H: Trying to understand push-pull output mode and open-drain output mode in a MCU's GPIO pin
I have a MCU (STM32H7xx) whose GPIOs, when configured as output, can be configured either as open-drain or push-pull. Before seeing this, I though that open-drain meant hihg-Z, however I don't see how that works just reading t... |
H: Over voltage and reverse polarity protection
I was trying to make an over voltage and reverse polarity protection circuit and create a PCB that I can easily use in some of my projects.
My level of electronics it's not so good, and that's why I'm here.
I thought one circuit, but as long as I know it's not so good:
... |
H: Circuit design - How to fix power supply overheating and reduced performance?
Goal
I'm trying to make a IOT radiator valve so I can manage the heating of every room in my house automatically with a system I'm building.
Context
I've pulled apart a cheap "smart" radiator valve to salvage its 3.0V (25 Ohm) motorised w... |
H: Biasing an inverting Op-Amp using a voltage regulator
When biasing an inverting op-amp input using a voltage regulator (say, L7805), at the non-inverting pin, can we use the same regulator to power other ICs or should we only use it on the op-amp?
Also, in the case of an inverting amplifier, does the op-amp needs a... |
H: Does my IR LED need a ground?
I have a circuit that connects an IR led to my Arduino. The positive leg goes to +5v and the negative goes (via a resistor) to a digital pin. However, I have since seen some pictures of IR circuits that also connect the LED to ground. Do I need to do that, and if so, how do I do it? (S... |
H: How does my 802.11 a/b/g/n wireless card determine the modulation to use?
I was thinking yesterday about how the 802.11 a/b/g/n standards all use different modulation schemes, but my wireless card manages to detect frames from networks that may use any of those modulations. So, when my card detects a signal contain... |
H: How to calculate fuse i2t rating when current is known?
How do I convert the fuse current rating to the i2t value? For example, in this circuit simulator, when adding a fuse, the only values that can be specified are the i2t value and resistance. The fuse I am attempting to simulate says 32mA.
AI: You simply get t... |
H: Bench Power Supply for ESC and KV on motor
I have a bench power supply it can provide ~10 amps and ~30 volts. Working on an autonomous car project I have an ESC to manage a brush-less motor.
Two questions I cannot seem to wrap my head around:
The ESC has a 35A requirements. With the bench power supply I have I can... |
H: Intuitive way of "visualizing" how the energy is stored in an inductor?
I've been trying to more or less understand intuitively how energy is stored in an inductor, but I don't seem to get anywhere decent.
In a capacitor I understand, I believe: an external battery pushes electrons and holes (going with the electro... |
H: 9v oscillator circuit that produces a frequency of 500 Hz
I am a gr 10 student that really has no idea what I am doing, however, I have made a circuit schematic and just need to know if it is right I guess.
AI: Aaron, Have you ever heard about a circuit simulator? It is a good way to learn a lot about circuits befo... |
H: Good design for reading a DIP Switch once
I want to read an 8bit DIP switch at MCU startup, after that it will be disregarded. I have enough pins on the MCU to read this directly. My question is; is it worth while to stop the power for the switch after it is read? Power is not a huge consideration but as it will be... |
H: How does a switch's series voltage affect discharge time in a relaxation circuit?
I made this relaxation oscillatory circuit in LTspice using a voltage controlled switch (sw) that switches off at \$ 100V \$ and back on at \$ 50V \$. To the left, the sw has \$ V_{ser}= 0V \$ series voltage and it takes the capacitor... |
H: Replacing two ideal with two linear voltage sources
I am currently learning how ideal sources may be replaced with linear sources to make the application of other circuit theory possible.
Unfortunately, I don't understand how the following conversion is possible.
This is the original circuit.
simulate this circuit... |
H: Help wiring relay to LED driver - L/N on driver to L/O on relay?
I have a Shelly Dimmer 2 wifi-controlled relay, and I'm a bit confused as to wiring it to my LED module. The front of the relay looks like this:
This is the LED lamp I am trying to connect. At one end is a normal 2-prong 240V mains plug (i.e. AU plug... |
H: Controlling AVR reset via voltage divider
I have an AVR atmega32u4 which is being run on 3.3v. I program it using a avr usbisp, which runs at 5v.. The problem i'm having is driving the reset pin.. I currently have this schematic where PROG_RESET is the 5V/GND reset pin on the programmer, and AVR_RESET goes to the A... |
H: How to repurpose an old PCB?
I am brand new to electronics and would like to know if there's any way to reprogram the microcontroller or reuse a used PCB. I extracted this PCB from my old Bluetooth speakers. Here's the image:
Also, I don't recognize which part is used as the Bluetooth or FM module or antenna on th... |
H: Do AC current sources exist and why or why not? For both actual and theoretical
I got confused when I encountered this problem on Chegg.
https://www.chegg.com/homework-help/questions-and-answers/5-find-ac-current-source-iin-polar-form-b-find-vt--c-choose-one-source-current-leads-sourc-q19121964
Question:
5.
a) Find... |
H: JFET series switch
The picture shows a series JFET switch. Is r_d itself the load or does the load have to be attached at the port v_out? If the second one is true then what is the purpose of r_d? Can't we replace r_d with the load we want?
AI: my question is whether r_d itself is the load or the load has to be
a... |
H: Amplifying the output voltage from a coil (10Hz-20kHz) using an AD620 module
Disclaimer: I’m computer scientist.
I would need some help to get an AD620 amplifier module to work.
Some context is available here in a previous question.
Here is a physical view of the amplifier:
The documentation was unfortunately in C... |
H: Why am I getting 239 VAC between GND and line when the device is turned off?
I noticed a weird thing that I don't understand.
I'm working on an electronics project which has inside of it a 230 VAC (I'm in Europe) to 12 VDC transformer.
For the convenience, the project is plugged to the Eaton ePDU G3, which is a sor... |
H: Where is the antenna in this remote control board?
This is a PCB of a (radio?) remote control.
AI: The antenna is the rectangular loop trace at the top edge of the PCB. Transistor Q1 is the oscillator. L1 is probably used to provide DC power to Q1, and C1 and C2 are part of the matching and resonating network. |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.