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H: Question about magnetic circuits
In the below page, I have two questions:
How can a magnetic circuit not consume energy?
How does the stored magnetic energy return to the circuit?
Source:
OBJECTIVE ELECTRICAL TECHNOLOGY
For the Students of UPSC (Engg. Services); IAS (Engg. Group); B.Sc. Engg.; Diploma and Othe... |
H: LF353 for 12-0V square wave from arduino
I have built the following circuit with an LF353N op amp and expecting 0-12V outputs from it.
I have built it on a breadboard but the output is always around +12V except the when the (+) input is floating, at that time it is around 6V. What I am doing wrong? Is the LF353 can... |
H: STM32-based USB microphone produces hiss
I'm building a USB microphone based on STM32F407 discovery board, it captures audio but produces quiet but noticeable hiss with its spectrum shown below:
I'm using oversampling to get additional 2 bits of resolution but the issue is present without oversampling as well (I j... |
H: No mention of eMMC random performance in datasheets
Any particular reason why none of the eMMC manufacturers mention random read or random write performance in datasheets ? Only performance mentioned in datasheets is for sequential workloads.
AI: None? I opened two random eMMC datasheets and they both do mention it... |
H: What is the lowest level of CPU programming above transistors?
In my CS program, my professor has claimed that NAND gates are the most basic gate to engineer, and so every other gate and higher-level circuits found in CPUs are made from NAND gates (no source found). I'm skeptical of this claim, as it seems prohibit... |
H: Why do my FQP30N06L MOSFETs keep dying after being powered up only a few times?
I am having an issue with my circuit. Specifically, with the FQP30N06L MOSFETs failing after only a couple of runs (a run being powering the circuit).
I'm using a 24V DC power supply and originally had a 3V Arduino running the program, ... |
H: Gate Driver Circuit Question
I read the PoE PD Schematic Review Guidelines, and there is a gate driver circuit I don't understand how that works. Can someone tell me how to work?
1.) On the page 22, the dotted boxes are the gate drives, I never use that kind of driver before, so I have no idea how to work.
2.) What... |
H: Controlling low voltage circuit with wall outlet power
I'm basically looking for a reverse relay: I want to switch around 5V with wall outlet power (230V 50Hz in my country). When wall power goes out, the low-voltage circuit should open. I don't have space to use a phone charger / wall wart, and I'd like to avoid a... |
H: What does "mode-free" mean, in the context of coaxial connectors?
I've seen a number of coaxial connectors claimed to be rated for "mode-free operation up to (whatever) GHz"--but after much searching, I can't seem to find any definition of "mode-free".
(source)
(source)
What does "mode-free" mean in this context?... |
H: hex value is treated as decimal value
This is from Mazidi's book on microcontroller. As we can see we are aiming to add these two values 17H and 28H in HEX and want to get their sum in BCD, definitely their sum is 3F and which should be
0110 0011, then how the book says "the result should have been 0100 0101? more... |
H: Resistor and potentiometer values to obtain 1.25-12V variable with an LM317
I want to make a variable power supply up to 12V. For that I want to select resistor and adjust potentiometer values. I have calculated below values from this website.https://circuitdigest.com/calculators/lm317-resistor-voltage-calculator
R... |
H: What is ORing and why is it named ORing?
I read some documents like the PoE application, it used ORing to protect the reverse input current. I would like to know what ORing is. I googled it, but I cannot find the answer. It seems like a diode or something the datasheet uses diode to protect, but I am not sure what... |
H: Battery charging from USB and max current
I'm designing a wearable device, which is powered by a lipo battery. It can consume up to 100 mA, with 2A short peaks. The battery needs 360mA for charging. Charging IC with power path is used.
And it is meant to be charged with a standard USB (micro-B or C). It will be a... |
H: What is the purpose of the D4 diode between base and emitter of PNP transistor?
I am having problem with understanding the purpose of the Q7 transistor. .
The anode of the D4 diode is connected to the base and cathode - to the emitter which makes Veb = -0.7V. This will always make the PNP transistor be on the OFF m... |
H: Reverse Battery Protection using P-Channel MOSFET
I read the TI document on page 5, according to this figure, when the GS of MOSFET from negative to positive the P MOSFET turned off, but why the Vout voltage will drop to minus.
AI: What looks to be happening is that the Gate-Source capacitance of the PMOS is not di... |
H: PoE system with Active Clamp Forward
Does anyone know if choose the Active clamp forward as the topology in PoE system,
according to this figure which from TI Design document, What's the function of C39. I do not understand why need to put the capacitor in there, is this DC block capacitor? can someone explain it t... |
H: -25mV output from op-amp with 0V input
I have this simple op-amp circuit used to amplify the voltage drop across an unknown resistor with a value between ~0 and ~20 ohms. The circuit works close to expected, but there is an offset - when I short RSENSE_A+ and RSENSE_A- with a "zero ohm" calibration shunt, I see 0V ... |
H: Are any op amp configurations better for noise?
Considering the fact that the noise is always modeled as a voltage source on the positive input, is there any configuration where you get lower noise gain than signal gain?
EDIT:
Found answer
AI: Generally, when you have any input signal with a given SNR, the SNR will... |
H: What do I find material to understand which electronic components are needed for a microcontroller?
I'm interested in designing a PCB for a keyboard, and I can't seem to find materials on learning what components are needed for the board (resistors, capacitors, diodes etc). I understand basic electronics, but in te... |
H: ATmega32U4 I/O Pin Alternate Functions
I am using an ATmega32U4 as a master with 2 slave ADCs (AD7739), ADC1 and ADC2. The two ADCs are identical. The SS, SCLK, MOSI, and MISO for ADC1 correspond to ports PORTB0,1,2, and 3 respectively, according to their SPI alternate functions described in the datasheet.
Now, whe... |
H: Why does lowering VDD increases the delay for digital circuits?
I've preparing for Physical Design Interview and came across couple of explanations that deduce that the delay of logical gates will increase once we reduce VDD. what is the reason?
my intuition sends me to the famous equation Q=CV. supposing Q is stil... |
H: Are there commercial split +/-5V DC power supplies?
I have a custom amplifier board that works with some scientific equipment. There is a molex-type connector on the PCB that requires +5V, -5V, and ground (3 pins). When I try to search for a +/- split power supply, I can find lots of do-it-yourself instructions fo... |
H: Is the dipping in VCC caused by inrush current of charging 1 uF and 0.1 uF capacitors?
I'm powering MSP430FR5994 microcontroller from a power supply using a 2.2 V regulator. This regulator can source up to 200 mA. When MSP430 turns on, it starts to charge a 1 uF and 0.1 uF by driving two pins high. The 0.1 uF is a ... |
H: Should I call these pins or ports?
I recently designed and built this DC-DC converter module for a college project:
The PCB has these pins/ports:
While preparing a datasheet for my project, I called them pins because they are male header pins.
After thinking about it for a while, I'm not actually sure whether I ... |
H: What are the factors that led to the digital revolution?
Historically, the electronic circuits used for communications and processing were analog. Now digital electronic circuits are widely used in communications and computers.
What factors drove this revolution from analog to digital?
AI: A few major developments ... |
H: Ringing in inductively coupled coils
My circuit consists of two inductively coupled inductors. A 40 kHz 600 mV sine voltage is applied to the primary inductor. The induced voltage in the secondary inductor shows some ringing in the area of its own resonant frequency (1 MHz). A capacitor with 180 pF placed in parall... |
H: Gate drive transformer troubleshoot
Recently I've been working on a half-bridge solid state tesla coil project.
After doing some research, I came across a lot of universal tesla coil driver schematics, and I've realised that a lot of the schematics use a gate drive transformer instead of a traditional driver ic.
Fr... |
H: What do schematic symbols (R, C) marked "SHORT" mean?
What does it mean when a resistor or capacitor is marked "SHORT" instead of being given a value in a schematic?
At first this seemed clear to me: it must mean a 0-ohm resistor, something I'm familiar with, although I'm used to seeing them drawn with a value of ... |
H: Not sure about the way to compute the voltage across a DC motor driven by a NPN BJT
Long story short, I wanted to make my own H-bridge but I was out of p-channel MOSFETS so I tried to design one with BJTs instead, but before doing just that I simply wanted to try to run an average 3-6V DC motor with a NPN transisto... |
H: Stereo Headphone Cabling (TRS) - Why 4 pads on L loudspeaker and 4 cables?
The R(ight) loudspeaker on my AKG-K99 headphones stopped working. I bought a replacement (x2) 'mini' loudspeaker.
After soldered the replacement the sound was "weird". No problem. I predicted that. Different loudspeakers, different sound! Fo... |
H: Will a 250V fuse work fine in a 1000V multimeter?
I busted my multimeter due to improper use (see Why would a multimeter give an unexpected current reading?) and so decided to change the fuse. Annoyingly I can’t seem to find a 15A 1000V 6.3mm x 32mm fuse, and the closest thing I can find is a 15A 250VAC fuse. I was... |
H: How to make a main switch toggle between two sockets (or bulbs)
Is it possible to simply (without relay) make a main switch toggle between two sockets or bulbs such that both of them are never ON or OFF at the same time?
I need to control two 12 and 9 volt DC adaptors connected to same device. Is there such a switc... |
H: Is the current on a motor's nameplate its no-load current, full load current, or locked rotor current?
Say a motor has 1.49A on its nameplate. Is this its full-load current, no-load current or something else?
AI: I would expect the nameplate to give the rated load current at rated voltage.
The no-load current may b... |
H: Make microphone less sensitive
I bought a pack of 5 MAX4466 microphones on amazon, and would need to use them to detect when a plate is hit by a bullet. There are 4 plates, each one with a microphone glued to the back. The bullet speed and the speed of sound are very similar, thus the microphone needs to be very to... |
H: Does electric resistance of an iron-cored electromagnet depend upon the size and type of the core?
I know that the resistance of an electromagnet depends upon the nature, length, and diameter of the wire. Is it also depend upon the size and nature of the iron core on which the wire is wrapped?
AI: The resistance wo... |
H: Why are arcs so hazardous compared to standard current flow?
I know that electric arcs are dangerous as they can start fires, cause explosions, melted insulation, etc. and they are generally undesirable.
However, I am a bit confused as to why. Arcs generate heat, but shouldn't normal current flow also generate heat... |
H: Use Tx port on SDR for an LO?
Designing a receiver for an experiment. The receiver will be in remote location and I will be deploying multiple in the field so have a cost-effective, self-contained system is a priority (is it ever not?).
I have an SDR I want to use that is ruggedized/weather proof and has an embedde... |
H: Is there any reason to use the LM317 in place of the better and more recent LM338?
This more recent version of the LM317 is fantastic, and while it happened some of my LM317s "fried" somehow, LM338s never betrayed me.
Reading the datasheets, I don't find any advantage to use the LM317 vs the LM338 voltage regulator... |
H: What does High-Impedance mean in digital systems?
I'm currently messing with the Microchip 23LC1024 SPI RAM chip, and trying to read the datasheet to understand how to work with it. I'm not an electronics engineer or something like that, I'm a software developer, so I don't quite understand everything that's writte... |
H: Adapting a 12V Dell power supply to a Lenovo PC - very naive questions
I bought on Amazon a chinese power supply for my Dell Latitude. It plugs into a 12V socket on my car and feeds 19.5V to the PC. So far, so good.
Now I want to feed another computer, a Lenovo thinkpad with a completely different socket:
I am thi... |
H: Average inductor current in Buck converter
In steady state operation the average capacitor current in a buck converter is zero, which means that the rippling part of the inductor current charges and discharges the capacitor, while the "DC" part of the inductor current is the load current. I am not sure how this "DC... |
H: How does this circuit generate a high frequency signal?
I am new to electronics. I am watching this video.
At 5:37, you can see the first half of the circuit generate a high frequency signal.
How do an op-amp, 9 VDC, and a few resistors generate a high frequency signal?
AI: It's called a relaxation oscillator: -
... |
H: stm32 nucleo 3.3V usage
This is probably an easy question. When using an STM32 Nucleo powered by a 5V power supply, can I use its 3V3 pin to supply 50mA? Or do I need to use for instance a 3V3 linear regulator attached to my 5V power supply.
Thank you.
AI: The NUCLEO-G031K8 dev board uses a LD39050PU33R regulator t... |
H: Why does this hand tool have this component?
I was fixing a corded electric handheld grinder (110Vac) the other day and there was something inside that I cannot explain.
The live and neutral supply into the grinder from the cord runs through a metal ring like component and are both wrapped around it twice.
Why is t... |
H: Can I simply adjust the output power of these laser diodes to meet my specifications? If so, then what are the consequences of doing such a thing?
I need a CW laser diode, with an integrated photodiode, with wavelength around 800nm and power 1-1.5mW. Although I didn't find anything that exactly matching my specific... |
H: Transfer function : Determination
I have the below circuit, here, I have Is and Va are measurable quantities. Rc1..Rc4 and Rbd are unknown variables for which I intend to derive transfer function. I have flexibility of adding additional resistances or switches in the circuit to get the equations. I am not sure how ... |
H: Counter potentiometer's varying linearity on a microcontroller
I have a sliding potentiometer and whilst its a linear one, it is not completely linear. I wanted to know if there was a way to filter out the linearity variance using mathematical operators on a microcontroller.
AI: Well, what you're asking for is call... |
H: How to source/name a 20 pin 19 position usb 3.0 connector
I am trying to find the male end of the connectors found on many modern computer motherboards which are used to connect USB 3.0 from a case to the motherboard. These have 2 rows of 10 positions (so 20 positions) but with only 19 pins (corner one missing). Th... |
H: How to define a throttle profile for PWM driven DC motor on a power wheels
I am building an arduino to output PWM to a simple low side MOSFET motor driver that's powering two DC motors on a power wheels Corvette. I will have a throttle input signal between 0 and 100%, but I believe the output PWM needs to be more c... |
H: Doubt about 50 ohm impedance calculation
I am developing a 4-layer FR-4 board containing a GNSS receiver (L1 + L2). RF tracks must have an impedance of 50 ohms. The board contains two inner layers of GND and a ground plane around the RF track:
To decide the thickness of the RF track, I used an online calculator:
h... |
H: Is something wrong with this series of assignments?
I am trying to cause a series of LEDs to grow steadily brighter over the course of about 30 seconds using an FPGA. However, my code is currently causing them to blink steadily for that duration. Running a Vivado simulation, I've found where the problem is occurrin... |
H: STM32 SPI Register Write
My original function had multiple 8-bit writes (wdata variable) and value inside the same array. This was transmitted by SPI master to a register. Now l'm porting to a new project that needs 32-bit address on the slave.
Original:
void register_write(uint8_t value)
{
/* Initialize array */
... |
H: dc offset removal
I want to manipulate dc offset of a signal. By using a RC filter, I can delete the dc offset when the cap is charged but there is some problem like frequency issue and long time constant. Any circuit suggestion would be appreciated.
Thanks in advance.
AI: If your incoming signal has a known, const... |
H: What type of connector does this flow-meter use?
I bought the following flow sensor:
https://www.adafruit.com/product/828
It generates pulses for each revolution. Now I connected it to Arduino via Dupont connectors. I want to make a proper PCB for my project. Please help me find the connector type.
AI: It looks l... |
H: Reduce coil whine in LED driver
I have designed a PCB to control RGB LEDs at various intensities using the PWM input to an ALW8808WT-7 driver from an STM32RCT MCU.
The 33 uH inductors in my prototype board let off an awful whine while the LEDs are running.
Is there a way to design around this for my next board? I h... |
H: UC3907DW which pins are the two batteries?
I have a project and want to power it from smart phone power banks.
Now 2.1 ampere at 5 volt is not enough to power a motor.
I want to combine multiple power banks (4) to provide enough current and voltage to the motor.
My issue is, most discussions warn against linking up... |
H: PMOS Saturation Condition
we know for nmos works in active region, we must have Vgs-Vth>0 and Vds>Vgs-Vth.
For PMOS can I write like this | Vgs|-|Vth|>0 , |Vds|>|Vgs|-|Vth|.
Please correct me if I am wrong
AI: You are wrong.
The terms \$V_{\text{gs}} \$ and \$V_{\text{ds}} \$ are polarity sensitive, so you cannot j... |
H: How can I manufacture an integrated circuit after prototyping with an FPGA?
I don't want to build the integrated circuit myself, I want to send the schematics to an IC factory to build my design and ship it back to me. Is that possible? I have finished prototyping on the FPGA.
So my question is, is there such a thi... |
H: How to utilize USB-Type-C connector as a normal connector?
I designed two custom PCB boards with one acting as my main Sensor Board and having a Controller (ESP32) interfacing all the sensors and peripherals. The other board is a programmer board that houses a CP2102 circuitry for converting USB protocol into UART ... |
H: Why won't this mechanical relay close NO contacts
I am trying to close the normally open (NO) mechanical relay contacts using the circuit below.
. The mechanical relay is Panasonic Relay.
I notice that when I give the high command for my GPIO I do see the LED turn-on and I hear a very soft click coming from the re... |
H: Estimation of single photon signal from photomultiplier tube data
I am trying to estimate the peak of a single photon signal in the oscilloscope by looking at the datasheet of the PMT (I am using Hamamatsu H7195 but the picture below is just for illustrative purposes).
I started with the luminous of the Anode and e... |
H: Can the FTDI232RL USB-to-serial device be programmed for 2 start bits?
I'm a hobbyist. I ran across a peculiar TTL-level UART, the 74LVC8153 (PDF). I'd like to connect one or more of these to a laptop using a USB-to-serial device, and the most widely used USB-to-serial seems to be the FTDI232.
Difficulty...the 74LV... |
H: Understanding sawtooth wave harmonics
I've been playing synthesizers for a while and I'm trying to understand their math and electronics better.
The sawtooth is one of the three common waveforms on most subtractive synths. The waves are generated by one or more VCOs and are modulated through LFOs and other sources,... |
H: Does a windmill generator spin faster or slower if no power is being tapped from it?
Title says it all. I can imagine it spinning faster because the energy that would be driving the generator isn't being tapped. But I could also imagine a scenario where a safety mechanism might prevent if from turning at full speed... |
H: FPGA streaming data
I want to know how to stream data from my PC to my FPGA and from FPGA back to my PC. I have a cmod A7 artix 35-t Xilinx FPGA. I have read some responses online but a lot seems to be quite high level and there are no sure details. I have heard, using ethernet protocol to send the data packets, US... |
H: Three different dimensions shown in package drawing, what do they mean?
I have an IC that uses this package from analog devices: https://www.analog.com/media/en/package-pcb-resources/package/pkg_pdf/lfcspcp/cp_8_5.pdf.
Most of the dimensions are shown in three numbers:
I can't find any information on what this mea... |
H: Can I control a PWM Fan with only a potentiometer?
If not, what else component do I need to control the fan?
I ordered the parts and is still yet to arrive and am a newbie in electronics. I want to know if this is doable.
Components I ordered: 5k, 10k, 20k potentiometer, different types resistor (220, 1k, 10k, 100k... |
H: Is it possible to use a diode in combination with a N-channel MOSFET?
I am new to MOSFETs and I could use some help!
I want to turn a DC motor on and off using a N-channel MOSFET.
I was trying some things out and I found that this works:
The motor turns on and off very quickly.
The circuit that I want to build is ... |
H: Communication between Controller and LED panels
I want to control multiple LED panels that have each a chap ATTiny on them which controls some WS2812 LEDs. There's a Master controller with an ESP8266 that is meant to send commands to the individual panels like Panel1: color=red.
Which would be the best solution to ... |
H: Solder SMD on through hole
Can I just solder an SMD part directly on the through holes of the PCB?
The pitch of SMD matches the pitch of the through holes.
AI: For DIY project, no problem.
If you manufactured a large quantity then you'd have to care about having a low number of defects which means taking care of al... |
H: Electronic circuit troubleshooting resin - is it normal?
I have just started my first electronics troubleshooting project of trying to fix our family's toaster. One of the first things I learned was that capacitors tend to be commonly faulty parts of a circuit and so by visually inspecting the board you can assess ... |
H: Loss-free resistor model
Can someone use a simple explanation to tell me what a loss-free resistor model is? I googled it but it is hard to understand. When I study power factor correction circuits, I see some papers use this model to analyze it.
There are my questions:
What is the loss-free resistor model?
Why d... |
H: Building a matrix audio mixer
I'd like to build a 4 in, 4 out, 9 V powered audio matrix mixer. Basically it's a mixer where each input has a knob to control the amount sent to each output, effectively forming a routing matrix, like this one.
But that one is a passive mixer, very simple but subject to massive signal... |
H: Are there two sorts of *geometry* of JFET?
In some schematics of JFET, we see in the geometry that the source and drains are perpendicular to the position of the gate.
Example :
https://en.wikipedia.org/wiki/JFET
In some schematics of JFET, we see in the geometry that the source and drains are parallel to the p... |
H: AC converter with MOSFETs
For this AC-AC converter circuit:
and these VGS signals:
I would like to know how the current flows through the circuit when the FET1 is OFF.
These are the output signals - VDS1 and VDS2:
It shows that when FET1 is OFF, FET2 is ON.
It can't go D2, D3, back source, because the circuit is... |
H: How to choose a transistor for PWRKEY on SIM808 design?
I am using a 3.3V digital output signal from a microcontroller.
The design documentation suggests using this circuit. How do I determine the transistor that I need?
AI: An ordinary general-purpose switch such as an NPN transistor or n-FET can work. 2N3904 or s... |
H: Why is this thermocouple amplifier with analog output circuit not working?
I am trying to assemble a circuit based on this datasheet:
The schematic I derived from the circuit is:
This was made into a PCB footprint
The readings I am getting from this circuit are much too low though. I am using GPIO2 on an esp-wr... |
H: PWM output power
I was learning about PWM circuits and something confused me:
If you have 1V going into a 1 ohm load for 1 hour we would get:
1V * 1A * 1 Hour = 1 Watt Hour
If you have 1V going into a 1 ohm load for 30 minutes we would get:
1V * 1A * .5 Hours = .5 Watt Hours
What if we had 1V at 50% duty cycle goin... |
H: capacitive leakage current
The question and answer is:
Why didn't he use the secondary voltage?
I mean it should be
a = Is / Ip = 5 / 2000 = 1 / 400
secondary voltage = 115 * 400 = 46 MV
Thus, leakage current = 46 MV / 10.6 MΩ = 4.33 A
Source:
OBJECTIVE ELECTRICAL TECHNOLOGY
For the Students of UPSC (Engg. Service... |
H: Help solving circuit with Mesh Analysis and Current Source
I've been for some hours trying to solve this thing with Mesh Analysis but I don't seem to be able to understand how to do it! Could anyone please explain how I can do this?
Disclaimer: I've never been told about Supermeshes or to "invent" a voltage V acros... |
H: How is the feedback separated in the block diagram given below?
How is the feedback separated in step 3 ? I can understand step 1 and 2 but not step 3.
AI: Try this: -
Hopefully that should be clear. |
H: Write EEPROM while flashing firmware in MCU
am using a STM32L0x2 device, Arm Cortex M0 core.
My goal it's to flash a default value in a EEPROM page during the firmware's flash.
Long story short: I want that when flashing the .elf in the MCU (I am using STM32CubeProgrammer) a specific EEPROM's page it's written with... |
H: Verilog non-blocking assignments
Consider the following Verilog snippet:
module mod1 ( input clk, input [1:0] a, input [1:0] b, output reg [3:0] c);
always @ ( posedge clk)
begin
c <= {c, &a, |b};
c[0] <= ^c[3:2];
end
endmodule
In my textbook it says
A group of blocking assignments are evaluated in... |
H: Is it possible make capacitors discharge like batteries do?
This question is regarding the possibility of use of capacitors as batteries.
One impediment in this is that the capacitor quickly discharges unevenly.
But here's how a typical lithium ion battery discharges.
Is it possible to regulate the discharge of c... |
H: Capacitor banks with opposite polarities
How can the polarities be opposite?
Source:
Distribution Switchgear
Professor A.T. Johns
ISBN (10 digit) 0 85296 107 3
ISBN (13 digit) 978-0-85296-107-0
AI: This is about AC distribution, so you can think of one wire as the neutral with 0V, and then the other wire is the ph... |
H: Gap between electrical connectors
Just wondered what the smallest gap between two soldered connections on a electronic item can be. The item is running at 24VDC and the series of 6x is running at 30 amperes.
How much gap can we get away with between the two connectors? The inspection document released has stated th... |
H: CS8406 Audio Interface (I2S->I2C)
I'm attempting to interface a MEMS Microphone with an ESP32 through a CS8406.
I am aware that the ESP32 has a well-documented I2S hardware interface however for my project I cannot use it. (It's going to connect to a smartwatch I developed in which only I2C and UART are broken out,... |
H: PWM controller for a servo coil (flow valve)
I am designing a PWM controller for a butterfly type flow valve operated by a servo. I have some information for the servo like input signal range (0-100mA), servo coil resistance (75 Ohm) and inductance (150mH). I am thinking of a simple architecture as per picture belo... |
H: Latching circuit with ATtiny85
I would like to know if this circuit will work if i power up an Arduino (via PWR)
I am suign this circuit as latching circuit and i do not know how to simulate it since i am new to electronics. Thanks in advance.
AI: This isn't really a latching circuit, as it seems like you are goin... |
H: Why a low pass filter across relay contacts instead of a high pass filter?
I have found a snubber, it is a low pass filter. It doesn't make sense to have a low pass filter across the contact. I would consider transients such as arcing to be high frequency; therefore, a high pass filter across relay makes sense in o... |
H: DIY: emulate button-press on garage door remote
I have a 3-button / 3-door garage door remote powered by a 3V CR2032 battery. I would like to use it in a DIY project where, by connecting it to a 3V circuit, I hope to programatically open/close the garage door.
With the battery in the remote, I've already been able ... |
H: Measure a circuit (small system current consumption using power source
I am powering a chip (CY8CKIT-143A). It is a BLE module + micro-controller. I am using it to transmit the data of a thermistor. I am using a DC power supply (Agilent E3644A).
I am powering the system with 3 Volts.
Can I use the current reading ... |
H: What is this Digilent Analog Discovery device doing in this experiment?
I'm a novice to electronics, and I was wondering if someone would clarify an experiment I just witnessed. A photodiode was set up to receive some signal. This signal is then read by a transimpedance amplifier. Finally, the signal is then “sampl... |
H: What is the purpose of a diode connected to the pins of a motor?
I am new to electronics. I am watching this video.
At 4:03, you can see a diode that connects the two pins of the motor:
What role does the diode play?
AI: This is called a Flyback Diode.
Motors tend to have a large inductance.
Once current gets goin... |
H: BJT(NPN) has a VBE higher than 0.7v
I am confused about this datasheet for a transistor I am using. From my understanding, most transistors have a VBE of about 0.7v but the max on this one is 1.2v which I thought would destroy most transistors. Does VBE(ON) represent something different than VBE?
AI: Look at datash... |
H: How to measure the temperature of a surface using an Arduino?
I'd like to measure the surface temperature of of a metal surface, to see how much that metal surface is heating up. I'm trying to recreate The EngineGuard.
The EngineGuard uses a 10mm washer, that is somehow capable of reading temperature. I've done a... |
H: Reusing PCB Components
What are some good methods when considering designing an automated system which can efficiently recycle PCB’s to extract copper and the components from the PCB which can then be reused and recycled?
AI: Recovering for re-use (as repair parts, or for refurbishment and use in new PCBs) is inher... |
H: TP4056 for Li ion deep discharge
I am using li ion single cell in one of the application where device will be in sleep mode when is not in use. Life time of which is nearly 30 days.
Cell I am using is Li-ion, 18650 package, 2600mah and comes with "1s 3.7v 2a Li Ion Bms Pcm 18650 Battery Protection Board Pcb".
For c... |
H: Desoldering capacitors - some get damaged and others don't
I was practicing desoldering components with a desoldering heat gun (Quick 861DW) of some boards I salvaged from a broken Sony Bravia HD-Ready monitor.
I applied 400C air flow and used some flux on the pads of the SMD capacitors.
On the first board I practi... |
H: Envelope detector followed by a low pass filter
What are the advantages of adding an RC low pass filter after an envelope detector? I am asking this because I often notice (in multiple studies) that this type of circuit logic (in the figure below) is used for information demodulation by first using a high-pass filt... |
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