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H: Breadboard circuit doesn't pay attention to sensor unless attached to multimeter probe?
Basically I'm using a programmable microchip to turn motors when a QTI infrared sensor reads a black surface. The sensor is connected to an LM293N comparator so that it outputs voltage on a black surface instead of a white surfa... |
H: When calculating the voltage in an AC Circuit, I get a different angle from the correct answer
Problem
I'am trying to calculate v2 from the circuit below, but my answer, 9.81cos(1000t+166.64°) mV, has a different angle from the correct answer, 9.81cos(1000t-13.36°) mV.
My approach
I tried to solve it with node ana... |
H: 50A Accurate Current Sensing Circuit Design
I'm trying to design a current sensing circuit that can achieve a 0.01A accuracy across 50A DC. It is a battery powered brushless DC motor drive (battery --> current sensor --> controller --> motor). I need the accuracy because I am trying to determine efficiency and ther... |
H: Gates and energy loss
i read in a book that when we have for instance a NAND or NOR gate ,the processor doesn't lose energy because we do not have direct current transfer from Vdd to Vss so the processor does not consume energy (apart from some leakage currents). I didn't understand it so much ,so my question is, w... |
H: How a BLDC work
I am working on a controller for a Brushless dc motor and I watched a tutorial about this (the only one that i found and that wasn't just a demonstration), but the problem is that some thing aren't explained:
I need 2 mosfets for every coil in the motor. Why? One side and one low side for each but ... |
H: Channel-Loss and Channel-Insertion-Loss
Read many time about Channel-Loss and Channel-Insertion-Loss, but confused that, is that same thing or opposite?
Which has +ve or -ve values in dB?
In reference to equalization of USB3.1.
AI: Read many time about Channel-Loss and Channel-Insertion-Loss, but confused that, is ... |
H: What is Full form of hFE of a digital multimeter?
In digital multimeter, there is a transistor-check function, and there is a term hFE. I do-not know how-to use-it, however, different Websites say it is a measurement transistor's gain ("the ratio of the Ic/Ib") such as: https://www.quora.com/What-does-hFE-mean-o... |
H: Understanding transformer datasheet
Preamble
I need an small isolation transformer for 0-6V 400Hz AC (this is my external signal, amplitude is the value):
I should get <10mA load from the primary signal source, and in the same time I need minimal size of the transformer. For <10mA at 6V 400 Hz the primary inductan... |
H: Neutral wire diameter and phase wires diameter (3 phase current)
I have nothing to do with electrical engineering so this may be lame question.
According to Kirchhoff's law sum of currents of L1+L2+L3 should be same as current of neutral wire. What puzzles me is why neutral wire has the same diameter as phase wires... |
H: is one "bigger" psu more efficient than two small?
I'm going to replace my router and network switch, and question is if both devices comes for example with 5v 1a power supply, is it good idea to buy one 5v 2a power supply and connect both devices? I know that power supply not used but plugged to wall uses energy. ... |
H: Confirm AC generator output frequency calculation
I am working on a project to build a small generator based on a 12 magnet, 12 pole, (6 pole pair) rotor with shaft speed of 2800 RPM. (Output voltage, 240 V AC, 4 kW.)
Estimated load will be 3.5 kW, constant on heating elements.
The value of output frequency con... |
H: Input resistor to BJT base > ground resistor, why?
Thank you for your time.
I'm new to electronics and so this question might, to you, call for an evident answer. Nevertheless, I can't seem to find that answer.
I've stumbled upon a schematic for a BJT-only, 4-bit computer. When I look at the XOR gate that's part of... |
H: What is the purpose of a tri-state pin in a Oscillator
I'm trying to interface this clock (32.768kHz Ceramic
Surface Mount Crystal Oscillator datasheet), but I'm confused as to what to do with the tri-state pin. What is it's purpose in the oscillator and should I care about it? Can I just leave it unconnected or pu... |
H: What is this type of connector called?
I frequently see it as the balance port connector on Lithium Polymer batteries, where it comes in 3-wire to 7-wire variants. What is its official designation?
AI: It's the XH connector from J.S.T. Manufacturing. |
H: Wire size for battery interconnects
I'm putting together a bank of 3 batteries, connected in parallel for use in a solar PV system. The primary load will come from a 1000W inverter (2000w surge). The inverter manual recommends using a 3ft. run of 25mm^2 cable to connect to the batteries.
Is the size of the intercon... |
H: LiPo discharge control
How to control the amount of current I drain from a lipo? U=I*R and I know R but how do I control the values of U and I? If the battery has 1000mAh, 10C and 10 V (I made this up), does the battery constantly drain 10 A at 10 V and I have to increase the resistance to lower the current?
AI: Th... |
H: when modeling a component, do you use the top or bottom view?
I'm modeling a component from this datasheet, they provide both a top view and bottom view of the components seen below, does my pcb footprint represent the top view or the bottom view? This has been very confusing to me.
TOP VIEW:
BOTTOM VIEW:
AI: The ... |
H: EAGLE: Just Routing and Drilling
I am trying to find the simplest way to mill this PCB with an Othermill:
Image 1
Image 2
I currently have both images saved in the R13 DXF format.
Basically, I'm trying to force the Othermill to behave like a ShopBot.
In EAGLE; Is there a way to bypass the schematic process, convert... |
H: Polar capacitors and a lack of jargon
Today I found myself wondering something about capacitors, and though my first reaction was to turn to Google, I also discovered that I don't know how to word my inquiry without getting ten thousand irrelevant results.
Assuming C1=C2, what would happen if polar capacitors were... |
H: Altium PCB Layout: The Difference of Through Via, Micro Via, and Burried Via
This is my very first time doing 4 layers PCB layout.
What is actually the difference between Micro Via and Buried Via?
Say I have Layer 1, Layer 2, Layer 3, Layer 4. What I know I use the Through Via for Layer 1 as start layer and Layer 4... |
H: How to decode ARMv7 instructions?
I'm trying to understand ARM instruction encoding.
The following image shows C code along with its corresponding assembly instructions:
I looked at the ARMv7 reference manual. However, I couldn't find the relationship between the machine code and the corresponding assembly instruc... |
H: Switching Voltage of Transistors
I am developing a system wich includes a laser-pointer and a digital LDR module. I'd like to switch the lasers with the GPIO pins on the raspberry. But, since I'm used to working with Arduino's and was not aware that the Raspberry has an 3.3V GPIO output, I bought lasers that ideall... |
H: Simulation model for floating gate
I am designing a non-volatile memory cell and foundry does not have model for floating gate . So I used the Voltage controlled current source to mimic floating gate. For output characteristics, I already had the measurement of previous fabricated custom made floating gate and I in... |
H: Using a MCU's UART as DAC
Many simple MCUs do not provide DACs despite having PWM output. For low clock frequencies like 8MHz, PWM does provide very poor quality if used for audio purposes. E.g., TI mentions in application notes that 32kHz PWM with 8 bit timing resolution would result in an analog signal quality co... |
H: How to use multiple input ports for internal ADC of PIC18F4550?
Is it possible to use the setChannel() command to switch between the inputs for the internal ADC of PIC18F4550 at the end of each conversion, e.g. from AN0 to AN1 and back, or register initialisation is required for input switch?
AI: You can write an i... |
H: DIY 2.4 ghz antenna for Bluetooth Speaker too cut or not to cut
I just built a Bluetooth speaker using a Sure Electronics AA-AB41136 Bluetooth 4.0 Audio Receiver Board. The reception was not great since it is a PCB antenna contained in my speaker box which is made out of 1/2" thick plywood. It seems a lot of people... |
H: 240 V instead of 230 V on a true RMS multimeter
I'm a beginner in electronics, and I've recently got myself a UNI-T UT61E multimeter, which is marked as true RMS. I stuck its probes into a mains socket and I was expecting 230 V (Europe/Poland) but the DMM showed 240 V. Is it possible that my meter is wrong, or is i... |
H: Visible light communication
I am working on a project which uses visible light communication. The transmit side consists of mosfet irf J40 and bc547 transistors driving a 3W LED. At reciver side I am using a 5mm pin photo diode PD 333 and LM 358.
I have a working model currently but the operating distance between ... |
H: Routing at right angle on via?
I heard it is usually better not routing at 90 degree angles. However what about with via, as I've read that it is usually recommended to use one layer for horizontal and another layer for vertical. Can I route safely like the picture below?
AI: In low frequency designs, the "90 degre... |
H: Reduce dev board schematics to custom board for production
There is already a post on here that is very insightful and related to my question "go from dev board to production board". However, I need a lower level understanding of schematics. I've searched the web for keywords like migrate hardware from dev board to... |
H: Equality of two 8 bit buses in 7400 series logic?
Is there a simple way to determine whether two 8-bit buses contain the same value?
I'm currently XORing each bit between the buses then feeding those results into a three-level tree of OR gates. (The top of the tree being a NOR, rather than an OR.)
This is 8x XOR +... |
H: How to build a slayer exciter
I am trying to build a slayer exciter.
I am using this diagram from Instructables:
I changed some components:
- TIP36C(PNP)
- 5oo turns on secondary coil using magnetic wire(0.8 mm)
- 5 turns on primary coil using normal wires
- 10-20 Vdc
- Resistance 10-30 Kohm
I also changed pol... |
H: Should a 555 IC remain powered when a [battery powered] device is turned off?
I'm fairly new to electronics. I wasn't able to find anything addressing this on the Web but that may be because I don't know the search terms to use.
I'm trying to design a device that contains two 555 timers. When powered on, one timer ... |
H: How can I make electricity with magnets
Please keep in mind that this is a new concept I am learn so I do apologize
Using electromagnetic induction How can I make electricity with magnets? And how can I produce a powerful supply of that electricity?
AI: Most electricity is made with magnets and coils. But you must ... |
H: eliminating audio hum
I'm working on a circuit that feeds a microphone into the ADC of the STM32F4 Discovery and then outputs that exact signal out of the microcontroller's DAC and then to a headphone jack.
I am able to hear everything that the microphone picks up, but I am getting a humming noise when listening t... |
H: Why is saturation region called so in BJT characteristics?
I understand base-collector (current) linear relationship is lost in saturation region and collector current will be lesser than \$ \beta * Ib \$ . Hence,at max, we can call such a region as non-linear region.
Saturation literally means something remainin... |
H: How can I learn interfacing microcontrollers?
My study field was computer and I'm a newbie in electronics.
I want to build a microcontroller based board (I think it is called an MCU board?) and when I search for example, how to interface lpc1768 with sensors, motors, Ethernet or USB port, etc, I will find many sche... |
H: IR emitter in reverse bias?
What will happen if light is shown on IR LED (emitter) when it's in reverse bias condition?
AI: It works like a photo diode. I.e. if photon energy is high enough (wavelength is short enough) to create electron-hole-pairs you get a photo current proportional to the light flux.
It might be... |
H: Interfacing a mains referenced AC measurement circuit with a PC
I need to connect an AC mains referenced measurement circuit with a notebook and I wanted to know if its safe to do that without an isolator. The measurement circuit primarily steps down AC voltage and current and then runs it through a set of instrume... |
H: Decoupling and bulk capacitor number and value
I am currently finishing a circuit with TIVA C TM4C123G where the user manual indicate the following:
"decoupling capacitor typically 0.1uF in value and should be accompanied by a bulk capacitor. The combined VDD and VDDA bulk capacitance of the microcontroller is typi... |
H: What's the standard way to detect a digital signal transition?
The 2-phase dual-rail protocol in the concept of asynchronous handshaking relies on detecting signal transitions.
How do we detect a signal transition from LOW to High or HIGH to LOW? What is the output of this detection? A permanent High? or LOW? or an... |
H: A question about the argument part of impedance
The definition of impedance is Z = V/I. I'm trying to understand the idea behind the argument part of the impedance concept in a capacitor.
First here is what I know briefly so far:
I will begin this by assuming the voltage across the capacitor is sinusoidal as:
Vcap ... |
H: About voltage divider resistor network
I need a precision decade voltage divider. And there is a product from Visahy just can do what I want. But it's soooooooooo expensive! So
Why they are so expensive?
I need the ratio tolerance at least ±0.05%. And if it's acceptable the absolute ratios may not be in 'decades'... |
H: Locating serial port
I'm not sure if this is the correct stack exchange site to post this, but here goes.
I have this PCB:
It's from this: https://www.vasco.com/images/DP270_Xpress_april11_tcm42-47389.pdf
I'm trying to locate a serial, uart port, if one exists. I don't have an oscilloscope or a multimeter, althou... |
H: capacitor RF performance
We have a standard SMD 0603 capacitor kit from that I picked a capacitor for use in a 868MHz Antenna matching circuit. I picked this 3.3pF capacitor from the kit.
The Q is listed a 1MHz, but I read somewhere that this value is not valid at 868MHz nor can the ESR be calculated from it at 86... |
H: Is it reliable to use Li-ion battery + LDO for analog circuits and 3.3v digital circuits?
I'm doing a project measuring ambient light with 'photodiode + op-amp + ADC + cortex-M0+.' For a while, I used stable DC source for providing 3.3v to every components.
The next milestone is making the module portable. What I f... |
H: How sine wave is generated in wien bridge oscillator?
It is known that the initial feedback signal is developed from the noise in the resitors and the transients of the power supply. The question here is : why the waveform at the output is sine wave particulary and not any other waveform?
AI: Barkhausens oscillatio... |
H: Replacing a 7.2 volt battery pack
I have a dead battery from my Tivoli Pal radio that I wish to replace. It is a NiMH 7.2V 1400mAh like this one (the mAh being the only difference I guess).
Would it be safe to take the connector off the battery pack with four two of these in serial connection? Would that give me th... |
H: What current rating does my kickback diode need to have?
This seems like it should have been asked before, but I can't find anything. I've got a large 12v DC motor (11A startup surge, 7a running current) that I'm PWM-ing at ~20khz through a mosfet.
I, naturally, need a flyback diode to keep the highly inductive mo... |
H: What's the point of DMA in embedded CPU's?
I was doing a project recently with the mbed (LPC1768), using the DAC to output various waves. I read parts of the datasheet, and it talked about how it had DMA for a lot of the peripherals. This seemed like it would be useful, but on further reading, I found that the DMA ... |
H: Measure delay of sound in wood with piezo sensor without an oscilloscope
First of all, excuse my layman terminology but electrical engineering is not my speciality.
I am currently trying to measure the delay of a sound wave travelling through different pieces of wood. I have already read on here that this is obviou... |
H: How/Why Do Bode Plots Work?
So when you derive the Bode Plot from the transfer function you plug jw into the transfer function H(s). You then get the magnitude of H(jw) and plot it to get the Bode Plot. My question is why does this work? My book simply tells me to plug in jw into the equation without giving me a... |
H: Powering a self-drive piezo buzzer with capacitors?
I have a project I am working on where I want to power a "self-drive" piezo buzzer for 20-30 seconds. However, in order to provide the power to this piezo, I would like to ideally use capacitors in conjunction with a PMOS transistor to trigger the buzzer. (The alt... |
H: How does this PIC board achieve RS-232 communication without a line driver?
All the develooment boards I have seen yet with serial communication support usually have MAX232 line trasceiver. However, I have come across this Olimex PIC-LCD development board that does not have it. Rather, it seems to use discrete comp... |
H: Open Collector Circuit Needs Pull-Up Resistor to Measure Frequency?
I need a little help determining what I need in order to measure frequency from an Encoder containing the attached Open Collector Output. The 5 Volts will actually be 24 Volts in my scenario (this is just the datasheet).
The device reading the out... |
H: What is the meaning of |H(jw)| concerning the transfer function
Noob question here but my books talks about the magnitude of the transfer function |H(jw)| a lot but I don't understand the meaning of |H(jw)| itself. Because of this I can't interpret the meaning of Bode plots of filters as it is the Y-axis of these ... |
H: Do capacitors increase voltage?
Just got a (220<-->12-0-12) transformer hooked up with a bridge rectifier and it measured 13 volts DC output from rectifier, but when I added a 1uF capacitor it just jumped up to 20 volts, and same reading(20 volts) from a 0.1uF capacitor, how is that even possible!?
Note: Nothing is... |
H: Measuring the bode plot of an op-amp circuit
So a few weeks ago I had to do an experiment and one of the exercises was to measure the bode plot of an op-amp. The instructions told us to measure the voltage and phase difference at the points \$TP_{37}\$ and \$R_{41}\$. During the experiment, one of the instructors t... |
H: A homemade programable voltage calibrator
I made a DC measurement board based on ADC and ARM. Now I want to add 'self-calibration in filed' function to it. I think I need a voltage reference and a voltage divider. And I don't want to calibrate my calibrator. I just need the voltage output error from the setting val... |
H: Lithium Ion Battery Capacity: Discharge Analysis
I have taken apart a battery module consisting A123 Systems ANR26650-M1A cells (they are technically Lithium-Iron-Phospate (LiFeo4) cells) that were used in a commercially controlled environment. After I charge them using a variable lab bench to the specified 3.6 vol... |
H: lm358 arranged as a 5 volt Buffer
simulate this circuit – Schematic created using CircuitLab
I am trying to connect my lm358 so that it acts like a buffer. I am connecting:
VCC to + 5 volts
Ground to Ground
Non-inverting input to +5 volts
Inverting input to output.
According to my research, connecting the out... |
H: Identify the change in switch states using a single wire system
Say I have 10 switches which will be automatically tripped at any time. The switches are supplied with the constant voltage(Say 5v). So the conventional way for identifying the trip is by connecting each switch to the GPIO's of uC and monitoring their ... |
H: What will increase output volume (dB) on a Piezo Transducer?
I need to achieve 110dB at 25khz from a Piezo Transducer. According to the datasheet, the resonant frequency of the Piezo is 25khz and at 10 vrms it will produce 110dB.
I will be using an MSP430G2553 controller's PWM pins to bit-bang it.
Currently, thoug... |
H: Trouble with rectifying a pulse with a diode
I'm trying to obtain a pulse from a square-wave of a function generator.
I thought it is an easy straightforward thing.
So in this case the square-wave is +5V to -5V. I use a 1N4001 diode and a 220 Ohm series resistor.
As you see in the below simulation output will go to... |
H: How does a Touch Screen Digitizer Tester work?
I'm currently replacing my screen for my Iphone and having issues with my touch screen dropping. The guy who sold it to me said he used this to test it.
http://www.ebay.com/itm/LCD-Display-Touch-Screen-Digitizer-Tester-for-iPhone-6s-4-7-6s-Plus-5-5-/112000947874
Now,... |
H: Introduce delay on a single bit signal w.r.t. input clock
I have seen this question and removed the "#.." part of my code to introduce delay, since my code will ultimately run on hardware.
Anyway, I am trying with counters and not able to introduce the required delay of n clock cycles. Here is my code:
`timescale ... |
H: What causes inaccurate time in 555?
I would like to use 555 with a relay to make a reliable control circuit.
I use 555 as mono-stable and the following equation does not work:
t = 1.1*R*C seconds
R = 51 K ohm
C= 220 uF
The output should be high (1) for about 12 sec but it does not. It is high for 6 or 7 sec only... |
H: Electronic switch with negative and positive voltage
I want to use a micro-controller to send data through a max232 that will convert the 0v/5v signals into -12/+12v signals. The problem with this IC is that when there's no signal, it sends a +12v signal which I don't want. I want to be able to control exactly when... |
H: Analyzing LC circuit with multiple inductors and capacitors
I have a problem understanding what's going on in a more complicated LC circuits with multiple inductors and capacitors
simulate this circuit – Schematic created using CircuitLab
with the two capacitors having the same size and the two inductors different... |
H: Gnd Loop for Bypass Capacitors
Can anyone explain if it's good to have the Gnd pin of a Bypass Caps tied to IC's Gnd? I've observed some design using those methods. Just want to have a justified answer.
I'm not sure if the thickness of the board plays a huge role in here.
AI: if it's good to have the Gnd pin of a ... |
H: Altium simulation time
I am currently working on a quite big project and I use Altium to simulate my overall circuit to make everything works as I expect it to.
I have something like 10 sheets linked to each other with feedback loops etc.
I have for the first time tried to simulate the global process today and it t... |
H: Never put anything on top of the fridge?
I've used several fridges (refrigerators) whose manuals say something similar to
Never put anything on top of the fridge.
The manuals don't explain why things should not be stored on top of the fridge which is frustrating when the top of a fridge is an ideal place to stor... |
H: How does charge/discharge current increase battery temperature?
I already know that charging or discharging a battery causes it to heat up, and that increase in heat is proportional to the current. But what physical process is behind this?
My back-of-the-envelope explanation would be that the battery has internal r... |
H: Pre-amplifying an electret mic already in use
I want to remove the DC component and boost to a line in level the mic signal of a regular headset plugged into a mobile phone while still allowing the mic to be used by the phone at the same time:
simulate this circuit – Schematic created using CircuitLab
I need this ... |
H: US Non-Polarized Plug Dimensions
for academic purposes I'm doing a very specific task where i need to calculate the Cell Constant of an American Non-Polarized Plug, ie, without same length the prongs.
So I need to know what are the dimensions of it, namely, length, thickness,wide and distance between the probes.... |
H: SPI Master: High impedance on MOSI?
I'm interfacing the Nordic nRF52 chip with an FPGA, and sometimes I need MOSI to be at a high impedance state (read "Z" in VHDL). Else the slave won't acknowledge that the data has been transferred completely (see here for the SPI Slave I'm using).
How should I do that properly?
... |
H: Precision voltage reference divider vs. constant current source to drive an RTD sensor
I need to measure temperature with an RTD between 0-300 C. I believe I have two options to make this work:
A constant current source feeding the RTD
A precision voltage reference and a resistor forming a voltage divider with th... |
H: Relay Vs MOSFET or IGBT
Curious on your thoughts for an application and the pros and cons of using a relay or a MOSFET or IGBT.
The application involves switching a 96V lead acid battery pack on and off for periods of 5 minutes upto 1 hour, there is no PWM involved so just hard switching. The load is just resistiv... |
H: How can I create two ac signals with a voltage controlled phase offset?
Is there a fairly straightforward analog circuit (resistors, capacitors, transistors, etc) to generate two sine waves of the same frequency and introduce a relative phase offset between them? So I'm looking to generate:
Sin[wt] and Sin[wt+c]
w... |
H: Can 600W PSU work on 1200VA AVR
This is probably very simple question for everyone on here, but I'm complete newbie when it comes to electronics. Anyway, I'm getting new PC with 600W PSU (my old one had 500W PSU), so I was wondering if 600W PSU would work on 1200VA Automatic Voltage Regulator.
I have this AVR.
AI: ... |
H: Why filter through hardware?
I am trying to measure a signal with a voltage amplitude between 10-100 microvolts and a frequency between 7-30Hz. The guide I am following suggests filtering out 60Hz noise using a notch filter, as well as additional LPF and HPF to focus only on this range (5 and 40 Hz), then one more ... |
H: Why is zero represented by 4mA in 4 - 20 mA industrial control systems?
Ideally, to drive a controller the required current must be just above 0 mA. However, practically we consider readings only taken from 4 mA as the valid data sets. Now, my question is why do we take 4 mA and not 3 mA or 2 mA? Is there any parti... |
H: How to estimate the settling time of the rotor of a stepper motor?
I'm trying to estimate how long I need my stepper's pulses to be to ensure I don't miss steps and assess how big the vibrations will be because of the ringing (i.e. how fast it can be, considering a fixed end-of-step precision requirement).
I've tri... |
H: Remove spikes from Load Cell readings
I have developed load indicator interfaced with load cell to display the value of load. The device is to be used in on-line weighing of a bag that is moving over the conveyor. Due to the mechanical movements there is a spike in load reading and in order to remove those spikes i... |
H: Auto shutdown and start of Raspberry Pi (remote application) using powerboot 1000c - need help debugging the circuit
In my application, the raspberry pi (A+) is remotely located and is powered using Powerboost 1000c. The powerboost is connected to a battery (lipo) and a solar panel. The battery is rechargeable and ... |
H: Magnitude of fourier transform of AM signal
I'm taking a basis course in DSP and in class we had an exercise on amplitude modulating signal. we were given a signal \$x(t)\$ with fourier transform \$X^F (f)\$
with magnitude which looks like this:
now, the modulated signal, \$x_{AM}(t)=2x(t)\cos (2\pi f_c t)\$ has f... |
H: Understanding MOSFET ouput characteristics on a log-log scale
I am a second year BS Electrical Engineering student, and I am working on making an autonomous robot in my summer vacations, nowadays.
Right now I am designing an H-Bridge using discrete components for my robots' drive motors.
So, here's what I have don... |
H: MC34072 maximum drawn current
How much current can this MC34072 op-amp deliver on the output? Not 100% sure on where to find it in the datasheet.. But is it on page 11 in the pdf document, where the graph shows supply current vs supply voltage?
AI: Output short circuit current is 30 mA (worst case) on page 4 of the... |
H: Modifiying variable inside of Interrupt vector. AVR
My question is again about modifying variables inside the ISR. If the variable used only inside of ISR, I don't have to declare it as volatile, right? After some researching, I figured out that variable need to be declared as static, and inside of ISR function. Bu... |
H: TO264 package at 100 Amps
I'm trying to design a BLDC motor controller rated to run a 200kW electric motor, 240v dc ~833A. Looking at MOSFETs I've found a TO264 n-channel which is rated for 500V 100A. How are the legs not going to immediately act like fusible links and vaporise?
Edit: I've found a more suited MOSFE... |
H: Meaning of micro-sd card symbols
I hope this is the right stackexchange site to ask this question. I'd like to now the meaning of these symbols, visible in the front of two different micro sd cards of the same model:
Backgroung (in case anyone wants to know): I have three sd cards, whose model is Kingston SDC10G2... |
H: How to modify this tank circuit to obtain a 3rd order passive band pass filter?
I am very confused about band pass- and band rejectfilters. I have this circuit which represents a bandpass filter. A 2nd order (2 energy exchanging elements) bandpass filter if I am not mistaking:
But to obtain a 3rd order BPF, should... |
H: ADC continuous conversion STM32F103
I'm facing with a problem regarding continuous acquisition of ADC channel in STM32F103.
I use the interrupt at the end of conversion to call a callback function to store the acquired value.
The problem regards the callback that is called only the first time.
I configured my proj... |
H: High side switching
I have designed a BJT based switch to enable and disable one or more loads with a microcontroller pin.
The situation is the following:
The controller pins work with 3.3V
The devices require 12V to work, and a current of 0,85mA flows at this voltage
I put together this circuit:
The schematic r... |
H: 250-350 MHz voltage controlled oscillator
I need to build a 250-350 MHz voltage controlled oscillator.
I have been checking out ring oscillators but they cannot reach these frequencies (max ~20 MHz).
Thus, I would like to know which are the usual designs for the range between 250-350 MHz. I suppose the best solutio... |
H: Why do simple H-Bridges that use PNPs combined with NPNs not short themselves out immediately (or do they)?
There is a simple design for an H-bridge that I keep seeing all over the place.
simulate this circuit – Schematic created using CircuitLab
This design is featured on the Sparkfun tutorials website as well a... |
H: When should an audio pre-amp use a differential input
As a guitarist, very familiar with the various types of noise that can wreak havoc with electric guitars, I've been mystified at how infrequently guitar amplifier inputs have employed differential stages. Of course low impedance microphone inputs have done so fo... |
H: Rationale for operating the diode in the (reverse biased) breakdown region
For the circuits I've studied thus far involving diodes (which admittedly are not that many), they have been nominally used in the forward-bias mode. For example, the LED only lights up when it's operated in the forward-biased region, and is... |
H: High current motor control
When designing for relatively high currents, e.g. 6-10A, what is the standard practice for motor control? Is it to construct an H-bridge out of discrete components, to use integrated half bridges, or to use integrated H-bridges?
AI: Having done all three, I can safely say "it depends".
Yo... |
H: How does the number of poles in an induction motor determine its speed and torque?
I notice that the higher the number of poles, the slower the induction motor spins. Likewise, the lower the number of poles, the faster it spins. How does the number of poles affect its speed? Also, does the number of poles have any ... |
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