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H: BLDC (Brushless DC Motor) vs PMSM (Permanent Magnet Synchornous Motor)
The differences between BLDC and PMSM are very small and for what I have seen while reading about it, is not clear to many of us. Most of the articles I have read say that the main difference is that the BEMF of a BLDC motor looks more trapezoid... |
H: Turn on/off ESP8266 by a transistor
I would like to turn off and on a circuit by another circuit. I believe that could be easily achieved by a transistor but when there is a voltage regulator and an ESP8266 with wide range of input current I'm lost.
I have the ESP8266 programmed to send a notification when it's tur... |
H: Receiving power from antenna (Homework)
The question:
"At a carrier frequency of 2 GHz, assuming a transmit antenna gain of 3 dBi and a receive antenna gain of 0 dBi, calculate the line-of-sight received power at a distance of 100 m from the basestation (in units of dBm). Assume 100 mW enters the transmit antenna p... |
H: Output impedance of STM32H743 MCU?
How do I find the output impedance of the STM32H743 (and potentially other similar devices)? I've looked through the datasheet (DS12110 Rev 5) and the reference manual (RM0433 Rev 5) however haven't found much information.
I'm mostly interested in the SPI lines, and want to match ... |
H: Multisim - How to create a 2-pin red/green LED in one part
I would like to pass the output of an LT1413CN8 op-amp through a 2-pin red/green LED (looks white when off) and back to it's inverted input.
In Multisim, there is a red/green LED option but that is a 3-pin configuration. If I drag and drop a green LED an... |
H: Understand limit voltage and current
It could sounds odd but I am trying to find a switch for my inverter that is an isolator.
My batteries are 12 V and my inventer can do over 5 KW, but I found a switch at 48 V, rated 300 A.
If I use it on 12 V what would be the max rated current for it?
AI: On a 5KW inverter the ... |
H: Adafruit audio FX mini and 2.5W amplifier
I am connecting Adafruit's Audio FX Mini board to a small Adafruit's amplifier. In order to save some power when the sound board is not outputting any sound, I wanted to connect ACT pin of the sound board with SD (shutdown) pin of the amp (PDF).
But if I connect directly th... |
H: Question on MOSFET - small signal model
In the small signal model of a MOSFET, the current from the drain to the source (for an n channel MOSFET) is a function of the gate to source voltage only.
But, if a positive voltage was not applied at the drain, the current wouldn't flow in the first place.
So, why is the d... |
H: Enhancement type MOSFET - channel formation
In an enhancement type MOSFET (an n channel one assumed here), when a positive gate to source voltage is applied, the holes of the substrate near the gate move deeper into the substrate away from the channel, and the electrons of the source and drain region accumulate nea... |
H: Pololu A4988 Decoupling Capacitors
My son (9yrs) has become interested in robotics. I did a course on it in college, but that was a LOOONG time ago and the course was much more rooted in programming than it was in electrical engineering. So, I'm learning as I go so that I can keep the project as wrinkle-free as p... |
H: STM32F103C8T6 - I2C communication with TI FuelGauge BQ78350
I am trying to establish communication between TI BQ78350 FuelGauge and STM32F103C8T6 using I2C/SMBus. The following is the I2C configuration used for the standard HAL I2C library.
static void MX_I2C1_Init(void)
{
hi2c1.Instance = I2C1;
hi2c1.Init.Clo... |
H: 240v AC Circuit Breaker for 24v AC
I am essentially intending to use this Schneider Electric A9F44120 MCB as an automatic brake for my wind turbine, which has an output of 25A @ 24Vac.
Can I use the normal 240Vac MCB for 24Vac?
Will it affect the current sensing ability or switching ability of the C.B? any suggests... |
H: How to calculate the voltage gain in this picture?
simulate this circuit – Schematic created using CircuitLab
I know that by using \$A_v=-G_mR_{out}\$, and \$G_m=\frac{I_{out}}{V_{in}}\$, we can get the voltage gain of this circuit.
After the small signal simplification, I got:
simulate this circuit
So, as node 1... |
H: comparator isn't behaving as it should
simulate this circuit – Schematic created using CircuitLab
The output is always outputting 5V, and I have no idea why. I have checked the inputs to the comp, I even switch them around its never hits 0 volts. Yes I am double checking that input from the OPA350 is greater than ... |
H: How to measure a 100 ohm differential signal on a spectrum analyzer?
I have a pair of 1.5V PCML differential signals coming out of an Altera Cyclone V GX FPGA, terminated on the FPGA in 100 ohms with common mode voltage = 0.65V (also provided on the chip).
I need to convert the 100 ohm differential signal to a 50 o... |
H: USB Camera to GPU Memory Directly
There may be several points in this question which may not make sense to a knowledgeable person, so I do thank you for your understanding in advance.
For a computer vision project I wish to process images from a camera array (10s of cameras) simultaneously and we wish to jam image ... |
H: What is a mask on a PCB?
I have an Arduino project that is mostly working on a solderless breadboard and I’m starting to plan on making it semi-permanent by soldering the components in place and mounting it into a project box.
I am thinking about using this Adafruit Perma-Proto Half-sized Breadboard PCB. Part of t... |
H: reflow oven issues with RO4003 PCB
Im trying to reflow some RF pcbs in a legit reflow oven. The PCBs material is "Rogers RO4003 305 Um" and 3 layer. (Its a very thin pcb)
If temperature is high enough to reflow the paste, the pcb changes color , and gets a little burned, degrading its usability.
paste type : CIF S... |
H: RF layout bend over Component
We lay out the RF trace for below model.
GSM 900MHz
RF trace maintain at 50Ω impedance. As I know, the RF trace needs to be as short as possible for better signal. Do we need to bend RF trace when tuning component comes in between? See attached image for a better understanding of my qu... |
H: Diode OR circuit drive current
Why is there no drive current available from the circuit below when R is connected to 0V?
The last sentance in this extract from wikipedia states that
If R is connected to 0 volts it will have no drive current available to drive the next circuit; practical diodes need a bias curren... |
H: Short-circuit protection, reverse polarity automotive
I am designing a power circuit and would like to integrate the ic VN5160S to protect it, but I have doubts about the position of it.
Would the ic VN5160S be before the DC / DC converter in my circuit?
I am feeding a microcontroller, canbus, bluetooth and rf.
th... |
H: PIR HC-SR501 and TIP122 - TIP 127 heating problem
I'm having a problem with a circuit commanded by a PIR.
I managed to ring a chinese doorbell when someone pass in front of the PIR but the main problem is the two transistors become very hot and I don't understand why.
The doorbell is a chinese model like this:
Thi... |
H: Two 9 V batteries in parallel
I don't know where else to ask this question and I think this is the best place so I'll ask here.
I'm making a remote controlled boat that uses two DC motor controlled by a L293D motor driver chip. It takes power for driving the motors from 4.5 to 36 V. To supply this, I'm planning on ... |
H: Are there any reasons I shouldn’t use a nodemcu’s 3.3v pin with this component?
I have this Hydrogen Sulfide gas sensor and the datasheet says the supply voltage requires a regulated voltage with a min of 2.6v and max of 3.6v
I can’t find any datasheet for the nodemcu v3 (spent hours looking, but none mention anyth... |
H: What if V+ = V- with an OpAmp?
In the two simulations below, Vout is almost the same (to GND) in both while the OpAmp sees the same differences in potential at its inputs, so actually, the second output should be 1V lower. How is that possible?
simulate this circuit – Schematic created using CircuitLab
AI: simulat... |
H: Motorization of a Shaft
I know this is an awkward one, but need some answers. Is it a good practice to fix/lock the shaft of a motor, and consequently the body of motor shall start rotating?
Essentially, there is a shaft which has a hollow diameter. I have to mount the motor inside the shaft (the outer diameter of... |
H: Open switch that will turn on an LED without power drain
I'm sewing a purse and I would like to put some LEDs inside of the bag that only draw on the battery and turn on when the bag is open.
The "switch" that I'm using are the metal snaps on the bag.
I have figured out how to make this work, but it slowly draws ... |
H: How to determine bandwidth available at USB ports
I am considering a mini-itx single board computer for a project that makes heavy use of USB. I want to ensure that certain USB devices have enough bandwidth. For example I have a data acquisition board that uses a bulk input but those transfer frames do not have gua... |
H: In 4 Layer PCB - which internal layer has to be consider to calculate Microstrip characteristic Independence for bottom layer
4-layer PCB stack-up as shown in attached figure - In case of bottom layer; which internal layer has to be considered to calculate characteristic impedance for microstrip line on that layer... |
H: MAX485 suddenly drawing too much current and output voltage levels are not right
I have two PCB that I designed and they are made by a PCB manufacturer (so they are identical). They use a MAX485CSA to communicate but suddenly one of them is drawing too much current, on a normal operation the circuit draws around 5m... |
H: LED's brightness difference in these 2 circuits
I have past exam's problem as follows. Suppose there are circuit A (left image) and B (right image). The question is why LED in circuit A is brighter than in B. The solution states that the Low-level output current (20 mA) is much higher than High-level output current... |
H: what is the good antena length for 433Mhz modules used for low distance domestic usage?
I want to use a low cost 433Mhz module for low distance domestic usage, but I need to solder an antenna , (there is a place for that on the reception module), to get a better signal across my walls. how to choose its length ?
... |
H: Why it is necessary to put two 120 ohm termination resistors at each end of CAN transmission line respectively?
Why it is necessary to put two 120 ohm termination resistors at each end of CAN transmission line respectively? Does it make an equivalent resistance of 60 ohm? (parallel resistors). Is it OK to put only ... |
H: Voltage sequencing on power up
I'm pretty new to PCB design, so my question may be obvious for some of you.
I am wiring the layout of an LCD screen on a PCB using KiCad. When I came to powering up, the datasheet of the AT070TN92 suggests applying DVDD voltage before AVDD. I know I can use voltage regulators to gain... |
H: Plot of a mixed signal in matlab
I have the following signal
xa=4000.*sin(2*pi*f1*t)+1000.*sin(2*pi*f2*t)+ 500.*sin(2*pi*f3*t);
and the values of f1,f2 and f3 are
f1=50000;
f2=500000;
f3=2500000;
and with the above information I have to find a figure like
in MATLAB. I am using the following code but not gettin... |
H: Memory choices for lack of arduino speed
I'm designing a system which reads values from a microphone and feeds it to the Arduino to calculate a few sound parameters. The measuring happens during a couple of milliseconds. The problem is that it's way faster than the processing speed of the Arduino.
So I was wonderi... |
H: How do eradicate pad to pad clearance with-in the component in Eagle Tool?
I tried clearing the error by defining Rules and net Class, but that does not happen. How to do this?
AI: The last version of EAGLE I used has a sticky 'accept' button when running the DRC, after that further DRC runs will ignore them.
I c... |
H: SPI: Receiving bytes from slave
For a couple of days I have been learning about SPI and decided to give it a go with 2 small devices.
DEVICE 1: Atmega328p (MASTER)
DEVICE 2: MFRC522 (SLAVE)
As far as I understand:
master sets SS pin low
master moves data to SPDR
as soon as data gets in to SPDR clock starts trans... |
H: Are standard USB connectors (Standard / Mini / Micro) Impedance controlled?
Are standard USB connectors Impedance controlled? Do they follow differential characteristic impedance of 90 Ohm for DM & DP lines?
Does standard Type A, Mini / Micro - USB Type follow same impedance match from PCB? Or Characteristic impeda... |
H: Determine the value of a constant for which the system is marginally stable
So I have the following transfer function
$$G(s)=\frac{s^2+0.1s}{10s^3 + 1.1s^2 + 0.01s + 2K}$$
Now I'm trying to determine the value of K so that I have a marginally stable system. I'm not supposed to use the Routh-Hurwitz method. I'm thin... |
H: SMPS and PCB layers
I am trying to design a ultra low noise SMPS with 20 W output (85 V to 220 V) and need to make a choice between a 4-layer and a 6-layer PCB.
On the 4 layers we plan on having components on both sides and two ground layers. Is this a good idea on the high voltage (250 V DC) side? Should I use a c... |
H: Differential Amplifier with active load
I came across this example in Razavi's Analogue CMOS IC Design book
The solution says that the for differential output, Vn does not change. Why not? Is it because any voltage drop across any of the resistors is essentially accounted for at either X or Y?
AI: Say you apply so... |
H: 8PST switches, do they exist? (not 8SPST DIP Switch)
I'm looking for a switch that can connect/disconnect 8 signals at a time with one button/lever/slide whatever. Power requirements are very low. I do not want to use analog switches due to interference with my measurements, which are in the nanoamp range.
I would ... |
H: Four-terminal resistor pinout?
Anyone can tell me (or preferably, point me to a source that explicitly shows) the pinout of the 4-pin current-sense resistors?
I'm seeing the datasheets for three different models (including Rideon's FHR 4-2321, the Powertron FHR 4-2321,and the PBV-R005-F1-0.5) and I simply cannot be... |
H: How to protect against a short circuit fail in 12VDC X capacitor?
When adding an X capacitor for simple line filtering in a 12V DC electronics project, how would you add protection against an unlikely short circuit failure in that capacitor?
Is it as simple as a fuse or something more interesting?
AI: You should no... |
H: Wireless LAN standard
I'm taking a module on wireless design and we were told that the IEEE 802.11b standard has a band of 2.4 to 2.4835 GHz and that it is divided into 13 channels. Now, my question is, does that mean that it can only support 13 devices at once? I couldn't find any explanation of this online.
I kno... |
H: Using narrower DDR RAM than controller
I have some ARM processor that have 72-bit width (8 for ECC) RAM controller.
Can I buy eg. two 32bit chips and combine them? If yes then how?
Can I buy just one 32bit and pull down rest of data pins on processor?
Processor brief if needed: https://docs.broadcom.com/docs/1211... |
H: Wrongly documented TI LM324 unity-gain bandwidth?
I was reading the datasheet of the LM324 from TI (http://www.ti.com/lit/ds/symlink/lm324.pdf).
They specify a generic GBW of 1.2MHz. This is usually done with no output applied, from what I understand.
Then there is the \$ A_{vd} \$ which is max 100K (100 V/mV). Th... |
H: WolframAlpha results for logic statement input
I was trying to simplify the following Boolean logic equation using wolframalpha.com.
(not (A) and B and C) or (A and (not(B)) and C) or (A and B and not (C)) or (A and B and C)
When I entered it into the box, it spat out the following.
Image is a link.
After showin... |
H: Purpose of Buffers in this Circuit
The schematic below is an H-bridge , the high and low mosfets are internal to the two ICs on the right side, their datasheet is here.
What is the purpose of the part on the left, which I googled to be a buffer IC, datasheet here.
Is it for the sake of circuit protection?
My under... |
H: Using an LIS3DH at LiPo Voltages
The LIS3DH 3-axis accelerometer specifies that it's supply voltage should be between 1.71 V and 3.6 V. For most applications, this just means you are using either 1.8 V or 3.3 V as your main rail. However, page 12 of the datasheet also mentions that the absolute maximum for the supp... |
H: Impossible to find the energy stored in an inductor without resistance and given a constant DC current source?
Here's my circuit:
simulate this circuit – Schematic created using CircuitLab
After doing some series and parallel inductor combining I get the value $$L_{eq}=20.8 mH$$
My question is, how would you go ab... |
H: Why does this microswitch datasheet specify a minimum load current?
The Omron VX series datasheet mentions on page 6 that "Using a model for ordinary loads to open or close the contact of a micro load circuit may result in faulty contact.", and shows that their micro load models even still require a minimum of 1mA ... |
H: What is the use of series resistor in VBAT line of CAN transceiver?
In the application diagram CAN Transceiver TJA1043 (Page – 19), there is a series resistor in the VBAT line.
What is the use of this resistor? How to select the value for this resistor?
AI: It forms a filter with the capacitor right next to it, m... |
H: At both posedge and negedge in Verilog?
In Verilog, I can use an always block and make it trigger on a positive or negative edge.
Is it possible to trigger the block on both the positive and negative edge, and thus have it basically clocked at twice the rate?
If so, does it incur a resource penalty? Does the compi... |
H: How can I find out which resistor is short-circuited and can be ignored?
I don't understand how the current flows in the circuit below. How do I deal with the wire between nodes c and a, a and b, g and d. Why is the 5 Ω resistor shorted out? I am having a little trouble understanding what results from short circuit... |
H: Mos amplifier numerical
Can anyone please explain how do I get this variation of Ix vs Vx curve?How do I determine whether the current will be in positive region or negetive?
AI: Using KCL in the output node, you find that
$$I_X = i_{DS1} - i_{DS2}$$
(I'm using positive quantities for the PMOS here).
You can see t... |
H: Replacing a capacitor
I have an electronic device that I have had for a good few years meaning that it's no longer in warranty. Recently it has developed a fault where the device will turn itself off when more power is being used. After looking online, I found that the cause was more likely a failing capicitor.
My... |
H: Arduino and USB, how it works?
After purchasing an Arduino board (UNO) I decided not to use Arduino IDE as it lacked some features and all libraries are written in C++. I am coding with C. One thing that I really do miss is a serial interface that allowed my Arduino to talk to PC it is connected to.
So far I am fa... |
H: Signal Strength to ADC quantisation levels
According to the excellent site of AB4OJ, the Icom 7300 in summary has a 14bit analogue to digital converter with a 1.5 volt peak to peak input (LTC2208-14). I make this to be 91.5uV per quantisation level. There is a 20db gain amplifier (LTC6401-20) ahead of the ADC so b... |
H: Simple way to create a disturbance on DC power
First of all, i must say that I am a software engineer, with very-low to no experience in circuits designs, and a very rudimentary understanding of electrical engineering and circuits. 101 really.
For a software project I am playing with I have built a small physical g... |
H: 12V Relay Actuation Depending on PWM or Constant DCV Input
I am looking to actuate a 12V SPDT relay depending on weather or not a 12V PWM signal is received or not. Headlamps use a reduced power PWM signal for daytime running lamps. I want to be able to detect that signal separate from a 12VDC source (normal headla... |
H: I have an idea/invention and look for a real investor/industry to take it to the next level?
I checked many online resources/websites and all of them asked me to pay thousands of dollars to make it real! I couldn't find any one that says you don't have to pay and we will take it from here once we hear about your in... |
H: Questions related to the calibration of a VNA?
I am seeking answers to these two questions related to the calibration of the VNA.
(1) What type of VNA calibration is required to measure the reflection, transmission, and phase of an attenuator?
[My Answer] Full two-port calibration, that is, TOSM type utilizing a c... |
H: LED light bulbs in low atmospheric pressure
I have these (https://www.amazon.co.uk/gp/product/B01DBOKZVK/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1) LED lightbulbs. Can I use them in a pressure of ~30kPa (21" Hg vacuum)?
AI: Yes. The plastic outer globes are not sealed. |
H: Reduce battery voltage.
I have grip warmers on a bike. basically just heat tape. I would like to reduce the supply voltage from lithium battery from 18 vdc to 12 vdc. My goal is to reduce warmer element temperature and increase battery life. What is the simplest way to do this? thanks!
AI: A resistor dropping... |
H: Analog logic circuit with adjustable threshold
I have a logic circuit currently consisting a few few AND gates and it's working fine (simulating) with if i use logic levels as the inputs. However my input levels might change in amplitude and I'd like to be able to control the logic threshold with something else (li... |
H: Parametric Equalizer with State Variable Filter
I'm new to this forum but hope to get some answers to a project I'm working on.
I'm trying to build an parametric equalizer with several bands (5 Bass-Bands, 3 Middle-Bands, 3 High-Bands). In the first picture below you can see the Middle-Band. I use a state variable ... |
H: Does this wiring pattern for a DB9 cable exist as a standard cable?
I have a scientific instrument that uses a DB9 cable to connect to the standard RS232 port on a computer for communication. I've deconstructed one of the cables as I needed to make another one but I am wondering if this wiring pattern is a standard... |
H: Q: MOSFET not providing correct supply voltage
I dont work much with mosfets so I dont really know how to go about this.
simulate this circuit – Schematic created using CircuitLab
So pretty much I have the circuit above, What's happening is that the Source of the mosfet is outputing around 3.3V and not close to 5V... |
H: What are these low voltage connectors?
Can anyone help me identify the kind of connectors in the pics below? Both the male and the female version. In case it helps, these are used in an LED fixture, to connect the (DC) output of the LED driver to the LEDs themselves. They are relatively small, roughly 15mm by 5mm b... |
H: What is optocoupler and how it is used?
Im curious about optocoupler.
What is optocoupler,why and how it is used in electronic circuits ?
AI: an optocoupler is a device used when you want to electrically isolate a circuit from another circuit that you want to send an electric signal
when you turn on the led it sen... |
H: What is this small unconnected solder blob on this PCB?
There's a small solder blob in the middle of this one-sided PCB (a switch-mode power supply), surrounded by unmasked board. The blob is 1.5mm in diameter, and the non-masked area is 4mm in diameter. There's nothing on the other side of the board, and there is ... |
H: What does [WEAK] mean in STM32 startup assembly code?
I was reading the STM32F407 startup file in Keil software to gather some information. I faced this problem: What is the [WEAK] symbol used for?
A part of the code that this symbol has been used in is:
Reset_Handler PROC
EXPORT Reset_Handler ... |
H: In what way VBW and trace averaging are different in spectrum analyzer?
We know both VBW and trace averaging intends to smooth the fluctuations of a spectrum.
But how do they differ from each other?
AI: Without getting into DSP and filter theory:
Video bandwidth works by 'smoothing' based on frequency points at hi... |
H: Instantaneous power consumption value
If, for a large motor, you are given cumulative kWh values at 5-minute increments, how would you determine an instantaneous power consumption value?
AI: You can determine average power consumption (kW) because it is kWh divided by hours.
Instantaneous power varies wih the cycl... |
H: If we have four grounded nodes in a circuit, can we connect two of them together and forget that those two were grounds?
Refer to the image attached. I personally think the answer is no because it is not necessary for the currents through both the grounded capacitors to be the same in the upper circuit, but that i... |
H: Can an electrical wiring system carry enough current to create an EMP?
I'm writing a spy story of sorts and I demand realism in my writing. In one of the chapters an agent, working with remote hacking assistance, enters a datacenter to steal digital certificates. When armed police arrive to storm the place and ente... |
H: 16 bit DAC microcontroller
I'm currently working on a audio project where I need to play a 16 bit depth signal with a speaker.
Right now I'm using an atmega328 for prototyping, two 8 bit shift registers (controlled by the MCU) and an R-2R DAC (and an LM386).
Given that the setup is not so simple, I was wondering if... |
H: Step-up (boost) voltage regulator
I recently purchased a step-up converter, the specifications state that it can boost 5 V to 30 V with varying input voltages.
The reason I purchased it was because the charger for my handheld vacuum cleaner stopped working, and the charger has very specific specifications that are ... |
H: Error (10028): Can't resolve multiple constant drivers for net "rf[7][XX]" at registerfile8x32.v
Hello Im making a register file 8x32 in verilog, the sim looks good but when I compile on quartus it makes
Error (10028): Can't resolve multiple constant drivers for net "rf[7][31]" at registerfile8x32.v(21)
Error (100... |
H: Why do I Have 800 pixels in PAL video line
I have a DCMI peripheral (STM32H7) that receives video data from TVP5150 with discrete VSYNC/HSYNC.
I have 306 (it should be 305, but there is a chance that this is because of the way I count number of interrupts) active video full line interrupts in one frame, with one l... |
H: Uses for 49.9Ω resistors?
It seems that both 49.9Ω and 50Ω resistors are a thing:
https://www.mouser.co.uk/Passive-Components/Resistors//N-5g9n?P=1z0wnltZ1z0wljo
https://www.mouser.co.uk/Passive-Components/Resistors//N-5g9n?P=1z0wljoZ1z0x8f8
Given that they're typically 1% tolerance, why have both? In particular, w... |
H: Can power transformers be used with higher voltages?
I purchased a Japanese transformer for a project I’m doing. It runs on 100VAC, not 120V, something I overlooked. Doing a quick search, Japan seems to use both 50/60Hz, based on the region.
It’s 30 years old and there’s no information about frequencies on it. I ha... |
H: VGA to composite circuit. Does it work?
I found a VGA to composite passive converter circuit online, and was wondering if it would work, if the VGA timings were modified to match the timing of composite.
Here is a relevant schematic:
AI: Yes, it works — at a very basic level. But no, it cannot adjust the signal tim... |
H: Output Impedance of Passive Circuit
I have a circuit with resistors, capacitors and inductances. I need to plot the output impedance of this circuit for different values of two components in this network. Do you know a program (either freeware or matlab) which I can use to do this?
Thanks in advance.
AI: You can wr... |
H: How to turn off 555 Timer for a period of time after Vout signal passes through
I have a single-shot 555 Timer. After triggering, output goes high for a period of time.
What I would like to do now: After Vout goes high and then low again, I want to disable the 555 timer for a period of 10 seconds. During this peri... |
H: Hardware implementations for a low-cost ADC array project
I wonder what would be the best hardware platform or architecture for implementing and building a lowish-cost system to sample audio capture over a large array of microphones or sensors? say, 300 or 500 audio channels simultaneously, and be able to transmit ... |
H: Circuit analysis for RC circuit
I have this circuit and want to calculate the voltage at v2 when t>0. v1 has a 6 volt step at t=0. I tried to do nodal analysis and came to 2 equations for the 2 unknown nodes, but did not know what to do from there. In order to solve this could I simply use v+(v0-v)*e^(-t/RC), with ... |
H: Type A female USB port
I ordered a Type A USB port because I thought all Type A USB ports were the same, come to find out after taking the laptop completely apart that the 4 prong 2.0 USB port I ordered was way different than the type A 2.0 USB I needed for the laptop, So I took apart a flash drive and that's also ... |
H: Application of offset voltage to non-inverting input of the op amp
When we analize the effects of the offset voltage at the outlet of an amplifier configuration, we consider that this voltage is applied to the non-inverting input. At least it appears so in all the books I have reviewed so far. Is there any particua... |
H: Analysis of voltage regulator circuit
I have found out the output voltage to be 9V.
To find power, we need \$I_CV_{CE}\$
We can find \$I_E\$ from the output circuit.
\$ I_E=\frac{6}{24k}+\frac{9}{10} \$
But can we find \$I_C\$? Or do we have to approximate \$I_C\$ approximately equal to \$I_E\$?
Will increase of \... |
H: LC circuit powered by MOSFET generates not stable
Sorry for poor English.
I have a transformer from an old TV and try to generate HV discharge. I've added a capacitor (C1 on the scheme) to get resonant frequency around 17kHz. Used coil 5-6 for feedback for the transistor T1 (IRF3808) and protected the gate with 5k ... |
H: The meaning and role of the phase in antenna measurements with VNA
VNA measurements of an antenna return Z, RL, Xs, Rs... and also phase. I usually check Z=50 and Xs=0 to reach the max Return Loss and the lowest SWR 1.0:1, without having care of phase values.
However I noticed that in some cases even if Z and Xs ar... |
H: Antenna polarization and antenna directivity are the same?
I'm working on an RFID project, and looking for information about the antennas that I have to use, I have the following doubt: Antenna polarization and antenna directiivity are the same? Thanks!
AI: No.
Polarization refers to the relative angles of the elec... |
H: Newbie question: C programing for AVR
The following lines which works exactly opposite to what i'm expecting, would appreciate correcting my understaing:
Button connected with Pin D2 & Led B2:
if (PIND & (1 << PD2) )
{
(PORTB ^= (1 << PB2));
_delay_ms(500);
}
else
PO... |
H: 74193 stops working after compilation on another PC (QUARTUS)
I got a Quartus project with a mod 22 counter using 74193 from a friend. It works just fine when I run a simulation before a compilation on my PC, but after I compile it on my PC, it stops working correctly. Is it possible to check what settings are diff... |
H: Can a Single Supply Powered Op-Amp Handle Negative Input Voltage?
I have an input sine wave at 300mV peak to peak. I want to filter this sine wave to eliminate noise and distortion.
I am planning to use the LMx58-N op-amp family, powered using a single supply: 3V to 32V.
Circuitry proposed will be based on the Mult... |
H: Let two LEDs blink with Raspberry Pi
I have written a simple Python program which runs on a RPi to make an LED blink. For that I connected my RPi using GPIO 23 with the anode of the LED, and before going back to ground, I added a resistor with 220 ohm. So far, this works.
Now I would like to make two LEDs blink, so... |
H: (Reasonably) accurate 1Hz clock generator
I would like your advice on components before I purchase anything.
I am going to make a digital 24hr clock using probably JK flip flops/multiplexors with 7 segment displays. But it must be battery-operated.
Is using a 32kHz quartz crystal, a good way of producing a 1Hz cloc... |
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