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H: rising edge (0 to1)and falling edge(1 to 0) detector circuit for flipflops?
I was surprised to see how flipflops change output on the rising edge of clock signal
AI: Rising and failing edges can be detected in several ways.
One is to add an additional flip-flop which serves a a simple state machine, so that only tr... |
H: Explaining the need for two transistors in Not Gate
I was reading:
http://www.cs.bu.edu/~best/courses/modules/Transistors2Gates/
To teach myself transistor logic, but I have some questions on what I believe are unnecessary strucutres (most likely since I don't understand their physical need).
In the construction of... |
H: If it's the amps that kills, why is it possible to survive a shock from a 12.4 amps?
"It's the amps that kills" you is well know and well documented. There are even charts showing the physiological effects of various currents.
According to several thread, there are people putting their tongue on the end of chargor... |
H: LM350 overheating below 2A
I am using LM350 for regulating 12V for 1.7A load. As per datasheet it can drive max 3A load.
But in my case, it's stops regulating after keeping this circuit for burn test for 3-4 days of testing. During burn test,randomly it stops regulating even though current is well below 3A.
I have ... |
H: Why led turning on when switch is low in pic starter kit?
I have a PIC starter kit. I am doing a simple program of turning on led when switch is pressed and then turning them off when switch is released like following:
if(switch==1)
{
led = 1;
}
else
{
led = 0;
}
I was actually not able to do above code in MPL... |
H: USB Device Latency
This is a theoretical question. I would like to know what the lowest latency is which can be achieved when interfacing a microcontroller with USB interface. Consider a USB host (computer) sending one byte to a USB device (microcontroller) and waiting for it to respond the same byte. How much time... |
H: Calculating sum resistance of multiple series and parallel resistors
!
I know how to find resistance, current, and voltage through series/parallel circuits. The problem I'm having is figuring which part of this circuit to simplify first. What is the correct order of operations for each branch? Or how can I redraw t... |
H: Data bus access in Intel 8086
I wonder how a multi-bytes instruction is executed when there is only 16-bit data bus? Assume the instruction is MOV AX,[10H]. The machine code of this instruction is 3 bytes. By combining the CS:IP registers, a 20-bit address is generated and there three bytes (which represents the ma... |
H: Bits are high on disabled pins(STM32)
For some reason I have many bits with value 1, even if they are supposed to be turned off.
I tried to debug it with some LEDs and Keil uVision debugger. uC is STM32F103 The situation is:
I have 2 pins configured as output and 1 as input.
GPIOA->CRL = 0x00000228;
When I try t... |
H: Question about the registers of an ADC
There are two things that confuses me in the below text:
"The ADC uses the successive-approximation method to perform the
conversion.The HCS12 uses two 8-bit registers to hold a ananlog to digital conversion result. The result can be stored either right- or left-justified. The... |
H: RMS OR DC value of the waveform is measured by DC voltmeter for the below input?
The DC voltmeter measures the average value of the waveform right?
I have read that ac voltmeters (high end) measure the RMS value based on heating effect while DC voltmeters measure the average value of the waveform.
My question is ... |
H: Noise figure in PSPICE
There is an example in OrCad PSPICE which calculates noise figure for an RF amplifier.
I know the following formula for noise figure:
$$\text{NF}_\text{dB}=10\log\frac{P_{no}}{G_aP_{ni}}$$
But in this example the software uses another formula:
10*Log10(V(inoise)*V(inoise)/8.28e-19)
Where V(i... |
H: Bus clock and prescaler of an ADC
According to my text book "A clock pre-scaler is needed for ATD module's internal cock (2 MHz conversion clock) to be configured to within the specified frequency range (500 kHz to 2 MHz) for different MCU bus clock frequencies.
For maximum accuracy, selecting the 500-kHz clock is... |
H: hybrid power supply
I am designing a hybrid power supply. The system is such that it will house an LDO and a switching regulator as well. The system has long intervals of sleep mode. Every now and then it wakes up and transmits/receives data. Its the transmission/reception times that a lot of current is drawn and t... |
H: Phase difference between voltage source's voltage and current
I tested a simple circuit with AC voltage source and, when I probed the source input for voltage and current, I was surprised to find that they were 180 degrees out of phase.
I tested in the LTSpice simulator.
Is it normally like that in real world or so... |
H: Which filter should I use? Just want to keep high count values
I am asking this question because I am not quite sure which filter I should be using.
Mine is simply a signal made up of discrete values as such s = [1 2 2 2 3 4 2 4 3 4 5 3 2 3 3]. Then I would like, per window size, a filtered signal. So e.g. if I us... |
H: Switching RJ45 with relays
So I am setting up an automated test environment for an electronic product and one of my needs is to simulate a user pulling the cable from the product. Since only 4 wires of the RJ45(T-568B) cable are used (https://www.iplocation.net/rj45-wiring), I am soldering these 4 wires (1,2,3,6) ... |
H: Voltage divider not functioning correctly
I have a Raspberry Pi connected to an MCP3002. It's power and Vref is taken from the Pi's 3.3V
I also took a two 1M resistors to form a voltage divider on the 5V connection to create 2.5V. Then on the pi I test the voltage using this code http://www.raspberrypi-spy.co.uk/20... |
H: Trying to understand float switch specs
I have a simple (maybe dumb) question about the specifications of a Square D float SW. This is the source:
Link to switch store
What is the meaning of 575 Vac 1/3 Phase, 230 Vdc?
is the nominal voltage between terminals? 1/3 is from one up to 3 phases or one-third of the pha... |
H: How do wires connect to transistors?
So I was looking at the schematic of NPN and PNP transistors which basically involved layered blocks of doped material stacked.
My question is how do wires connect to these devices? I think this image is misleading as the actual width of the n segment would be on the order of 5... |
H: Can the parameter \$\alpha\$ and \$\beta\$ be used for any BJT?
The reason I ask this question is because the statement in this wiki page. It says
The common-emitter current gain is represented by \$\beta_F\$ or the h-parameter \$h_{fe}\$; it is approximately the ratio of the DC collector current to the DC base cu... |
H: How much current can this 74HC245 handle on each output pin?
How much current can this 74HC245 handle on each output pin? Is it 20mA, 35mA, or 70mA?
I don't understand what the difference between output current, output clamping current, and supply current is.
http://www.nxp.com/documents/data_sheet/74HC_HCT244.pdf
... |
H: Multiple switches, same function. Can they be wired in parallel to a single I/O pin?
I'm working on a Raspberry Pi project that requires 30 separate momentary switches to be hooked up to trigger the same function within the software. It's for an art project.
I don't need to distinguish between different buttons - ... |
H: Effects of DC offset and loading at the input of an envelope detector (simple diode demodulator)
I am currently designing an AM radio. I am utilizing a diode demodulator
(https://upload.wikimedia.org/wikipedia/commons/6/6c/Simple_envelope_detector.svg)
to extract the envelope of my carrier signal. I am using a 1... |
H: ADC conversion timing
Why the conversion time of an ADC is calculated as: number of bits in resolution+number of programmed sample clocks+2/(ADC clock frequency) ? As far as I know for the successive approximation A/D converter, a clock cycle is the time it takes for a bit so number of bits in resolution would giv... |
H: Large Frequency Divsion
I am currently trying to design a circuit that needs a large frequency division, 25353 to be exact. I'm aware that I could do a large complex flip flop arrangement to achieve close to the desired results, but I'm guessing there is a more elegant approach that I am unaware of. Maybe an IC t... |
H: Window comparator using LM339 - invert output
I'm using the LM339 for an application with different voltage ranges. I am using the window comparator circuit since I want to test a specific range (4 - 8V). The circuit shown below actually identifies this "window" but not as I am expecting. When the input value is in... |
H: How does the transistor in an op-amp log amplifier work?
In the figure, you could connect the transistor Q1 as a diode by shorting its collector with its base, but instead it is done by keeping both base and collector at ground.
The text says that if it were connected the other way (by shorting collector and base) ... |
H: Is it possible to reverse engineer a ROM chip by grinding and taking photos?
Recently someone made a claim that you can reverse engineer a ROM by physically grinding the chip and taking pictures of the various layers.
Is this really possible?
AI: If it is a ROM that stores its data in physical features (a mask ROM,... |
H: Microprocessor modules in series
I have a 12v solar panel which gives 500mah most of the time...
I have two microprocessors with onboard 3.3v voltage regulator, which consumes around 400-500mah.
Can I connect the microprocessors in SERIES to the solar panel without any problem?
If your answer is no, any alternativ... |
H: Can I play sound from USB, Not from sound card?
I made an FM radio transmitter circuit and it works. It is supplied using a 12 volts transformer. The input of the transmitter is connected to the output of my PC's sound card (just like the way we connect PC loud speaker).
I would like to supply it using USB so that ... |
H: Voltage follower/Buffer circuit as summing amp
Is that possible to use a voltage follower/buffer circuit as summing amp?
In history, what kind of circuit was used for summing amp before people started to use those inverting summing amp circuit?
-ref buffer circuit
http://www.learningaboutelectronics.com/Articles/Vo... |
H: Protect soundsystem from GSM/GPRS pulsing noise sounds
What is the best way to isolate soundsystem from an modem/cellphone to not hear pulsing noise sounds when GSM/GPRS communication is active.
AI: I assume by 'soundsystem' you mean either a PA (sound reinforcement) system, or a hi-fi system? The practical answers... |
H: LC circuit problem
How does the LC circuit respond to the DC input?
Initially, when the switch is closed, at that instant the inductor is a short and capacitor is open so the diode cathode is floating. How does the diode conduct?
Does the LC circuit resonate?
My attempt at the solution:
Under steady state the cap... |
H: Incorrect voltage readings from ADC and op-amp
I recently posted, but my schematic changed and so did my problem.
I have this set up and on my raspberry Pi I have this code running which gets the 10-bit number from the ADC and converts it into a usable voltage for me.
#!/usr/bin/python
import spidev
import time
i... |
H: investigate the influence of the collector current on the base current in an n-p-n transistor
simulate this circuit – Schematic created using CircuitLab
why does the base current decreases as the collector current increases?
And as the base current increases the collector current also increases. Why and how?
Than... |
H: Can a nRF24L01+ chip work alone? (i.e. without Arduino borad)
I have a prototype based on the ESP8266 wifi tranceiver as a standalone module, without any Arduino borad.
It works fine, but I have heard that the nRF24L01+ chip is less power consuming.
After some online research, I think there is no possibilities to... |
H: Find the first-order transfer function from a measured step response data
In a school experiment, we had to measure an output voltage from an IC. We gathered the data with respect to time. Now we have to find the transfer function given the output data.
I think the whole experiment was treated as a first order ope... |
H: Wiring an SSR rasberry pi with an SSR-10DA
I have an SSR (pictured) that I intend to wire up to a European 220v appliance (in Norway) and a Rasberry Pi. It appears from this post that no diode is necessary (with an optional 1k resistor).
So then I would just take the 3.3v power, via a 1k resistor, to the GPIO pin t... |
H: Bode plot of Transfer Function
can anyone explain why the graph is shifted up vertically by 40dB? is that what we have to do by summing all lines and then shift them up by the amount of DC gain?
I know that the DC gain is 20log10(100)=40dB and I can see where poles and zeros are.
Also, how can I find the slopes f... |
H: Can a 38kHz IR receiver module (TSOP38238) decode 870Hz pulse modulation IR?
I'm trying to reverse engineer my A/C remote controller IR.
I've decoded the IR signal as a NEC code with the PJRC IRremote library.
My attempt to retransmit the same code to A/C unit was unsuccessful.
Having a look at the IR code with a l... |
H: Given thermal capability of a transformer, how to best estimate the voltage regulation?
I'm working with a system that has 3 2MVA transformers for which there is an existing estimate of the peak load and the power factor. The xfmrs appear to have a greater thermal capability than the rating (up to ~120% per xfrmr),... |
H: CMOS: Why is an nMOS transistor a bad conductor of high logic, but a good conductor of low?
I can't find an answer that addresses this and makes sense to me. I know that V_t is subtracted from the 'output', but I don't understand why.
AI: It's all to do with gate voltages.
A standard Enhancement Mode NMOS requires ... |
H: Smoking Transistor in Low-Side Switch. What Am I Doing Wrong?
I have some of these (RGB LEDs with drivers). They connect to 12V, and they draw a max of 1.8A total (full white):
I wanted to add a low-side switch to turn the load on/off via a PIC I/O pin output. After getting some advice in this thread, I created th... |
H: In a Voltage Regulator, what is it that decides the maximum resistance of the resistor and why?
I need to find the maximum resistance that R can have. This is what I know:
10V<=Vin<=15V
Iz>=0.2mA
0A<=IL<=1A
Vz=5.7 V.
hFE=50
I have derived the equation \$R=\frac{Vin-Vz}{I_z+\frac{I_L}{1+hFE}}\$
But how do I know whi... |
H: 2 circuits with different power sources
First of all, I know very little about electronics, so my question may seem very stupid.
I have 2 circuits, both have a microcontroller but they have a different power source (both powered by USB, but from a different source). The first circuit should be able to output an ana... |
H: Voltage to segments on 7 segment display?
I am thinking of purchasing an LTS4680 seven segment display for one of my projects.Here is the datasheetdatasheet:http://www.icpdf.com/icpdf_datasheet_7_datasheet/LTS4680AE_pdf_1732299/LTS4680AE_datasheet.html
I understand that it is a common cathode 7 seg display, so grou... |
H: Reversed Current in Passive Loads?
So I'm starting with the Nilsson/Riedel electronics text and got confused early on. They show a simple loop circuit (figure 2.15 for those who have it) with 1 ideal voltage source and 3 resistors and, across one of the resistors, the current flows opposite to the rest of the circu... |
H: 555 timer output current
I'm designing a 555 timer circuit where I want to control the brightness of an LED array. There is a minimum lux requirement for the array so I need to know the output current when I have a 4.8 V source.
This is a similar diagram. The only difference is I have a 4.8 V source and an LED ar... |
H: Is the circuit a Parallel RLC if there is a voltage source in between capacitor and inductor?
simulate this circuit – Schematic created using CircuitLab
As the schematic shows, there is a voltage source in between capacitor and inductor. Is it a valid Parallel RLC circuit. For example: can we say that we can use... |
H: How to compute Vds for this MOSFET transistor
Hi. I am confused when calculating Vsd in this figure as the resistor Rgd makes it an unconventional circuit to calculate when I apply DC analysis on it. How should I go around doing this question? Is there anyway that I can thevenin's Rg2, Rg2 and Rgd together or some... |
H: Activating apartment building buzzer "Door" open button remotely
I often times have difficulty getting to the buzzer of our building quick enough for FedEx and UPS, etc... or when I get visitors, they are sometimes inpatient and keep buzzing even though I'm still trying to get to the buzzer to let them in. I'd lik... |
H: BJT vs Mosfet, switching variable current battery powered device
I have a device that runs on voltage between 3v and 3v3 and consumes current anywhere between 4mA and 50mA. The device is powered from a battery with a 3v3 regulator.
I need to design a circuit that can switch on/off the device and I can not decide be... |
H: What is the purpose of the sharp edges (aka mouse bites, aka perforated breakaway tabs) on the PCB?
I have received an NVIDIA Jetson board this week and it has the following edges near the mount holes:
I did a quick search on the internet but was only able to find similar edges on the Raspberry Pi Compute Module:
... |
H: What operation does this circuit perform?
I have an assignment due for school, but this one question has been getting the best of my group-mate and I for about a week now. I am in no way asking you to solve the problem for me, but could you please make it a little bit simpler for us to understand.
Question:
If the... |
H: How can I use electronics right below their operating temperatures?
Where I live (south of Sweden) is usually just below 0 Celsius night/day entire dark winter. I would like to set up a network in my garage which is wood and doesn't have any heating system.
The electronics I am planning to use (like powerline, swi... |
H: Plotting bode plot of the transfer function
two poles p1=1 and p2=25
two zeros are z1=100 and z2=origin
and the DC gain is 20log10(10)=20dB
I know that that the Dc gain Is 20dB which is a straight line with slope of 0 ,
The zeroes have 20dB slope, but I don’t know how to find amplitude of poles ( vertical positi... |
H: FT232R chip and capacitor
The question is basically: why use capacitor in this particular DC circuit? Generally, as I read in the thread below, using a capacitor in DC circuit may have different reasons and purposes. Given my lack on knowledge in the topic I do not know what is the reason for using it here.
What is... |
H: Can a lighting transformer be used to power a pump?
I have a pump that draws 60W at 12V.
I had a little old linear hobby power supply I was using to power it in the garden but condensation killed it. Not a surprise but I needed the pump working more than I cared about the PSU.
I have a couple of waterproof lighting... |
H: How to power a lower-power circuit and an audio amplifier off the same source efficiently?
I want to create an audio amplifier that powers itself one when it detects audio coming in. I've found a low power IC that can signal when audio is present: NJM2072.
I figure I could use that switch to throw a relay or simila... |
H: Using "oscillator" rather than crystal for MCU
I'm kinda new to this so the name is based on Digikey. I have a PIC24FV32KA304 and I want to put an external oscillator of 32mhz. I found out that an oscillator like this one is a bit cheaper than say, like this one.
This is the configuration I thought using a crystal ... |
H: Integrating charge from known current
So I'm given a parametric formula for current measured across an ideal basic circuit element. It is \$i = 0 A\$ at \$t < 0\$ and \$ i = 20e^{-5000t} A\$ at \$ t\ge0\$ (t being time, in seconds). I'm then asked to calculate the total charge at the higher potential terminal.
The ... |
H: Is there a reason why some ac/dc adapters don't have a grounding pin?
I'm searching for an AC/DC adapter of 6v 300mA, but I can't find one with a grounding pin (E-type). Is there a specific reason for this?
AI: These types of power supplies are always isolated. That means there is no direct connection between the ... |
H: Opposing Ideal Current Sources
So I'm looking at the circuit below and a little confused by it.
How are there two current sources facing opposite directions? What does this even mean and how can it be a valid circuit, since current can only travel one direction?
AI: \$v_x\$ can be negative, and in fact it is. Even... |
H: Powers Signs differ between sources and loads?
Alright, so my textbook specifically states that negative power indicates that power is being extracted from a device (I'm assuming they mean for loads) and then shows a negative power value at a current source as being power delivered.
Is the sign convention opposite ... |
H: Help understanding the voltage waveforms across the components of a series RL circuit
The waveforms shown below are voltages taken across a 10 Ohm Resistor (pink) and an 1mH inductor (blue) in series with one another. The circuit is excited by a 1 kHz, 1 volt peak-to-peak sine wave. What is happening that causes th... |
H: Is it always possible to reduce the number of layers on a PCB by making the board larger
I see that a 2 layer PCB is really cheap to prototype. A 4 layer PCB is almost 4x more expensive . I have a design that uses DDR3 RAM where I need to match trace lengths. However I also need to keep the costs down. I observe th... |
H: Optimal voltage range for A/D Conversion
Why the voltage corresponding to the ADC result of 25 is 1.07 v (for a 10 bit A/D converter with a low reference voltage of one and high reference voltage of four) shouldn't the A/D conversion result be as it is , meaning 25 volts? In the manual it says the ADC result is m... |
H: Not able to understand the behaviour of PIC18F458 ADC output on PORT B with LED's
I have recently started meddling with the PIC18f458. The below shows the code in which I have configured the internal 10 bit adc.
#define _XTAL_FREQ 10000000
#include<P18F458.h>
#include <xc.h>
#pragma config OSC=HS
#pragma config WDT... |
H: Getting transfer function from block diagram
I am having trouble figuring out this step in an example question I've been given.
I'm supposed to be finding the 'transfer function in the forward path'.
This image shows the block diagram (top) and what I have been told is the correct forward path transfer function (c... |
H: How to "unground" a low state of a not gate
I have a seven segment display(LTS4680AE) and the anode of each segment keeps getting grounded. So I basically have a 4 bit adder which adds two 4 bit numbers and produces a 4 bit output. This output is connected to the input of a 4x16 decoder.The decoder gives out a "lo... |
H: How to design ESD and EMI -safe circuits?
First of all, sorry if this question is too low level or stupid, but I really wonder how to design ESD and EMI(electromagnetic interference) -safe circuits. I have read the user manual of my FPGA board, It said it has electro static discharge protection in IO signals which ... |
H: Atmel D20 garbage in USART output
I have an Atmel SAM D20J18 uC. I'm trying to print something via USART. The first few symbols are ok, but after 8-9th symbol there is garbage. However, if I run the code line-by-line in debug mode (with SAM ICE JTAG), all the symbols are printed correctly. I'm sure that I have corr... |
H: FT232R chip supply capacitors location
Here I asked a question why to have the capacitors:
FT232R chip and capacitor
But now the problem of their proper setup arises i.e. how to include the excerpt at the bottom of the picture in the whole circuit? Also I have a fundamental question here. Isn't it so that when I co... |
H: How do I read digital input on atmega series and use it in such code?
if (pin1 of port c high)
{preform a task
considering that
pin 5 and 6 are connected to an rtc via i2c and pin 0-3 is an input from lm35 (which I was able to write a code for) :p
using atmega8
I've set the ddrc with the following command > ddrc=... |
H: HDDs after format
What happen to our hard disks after formatting the partition with quick format option, from the electronics view? Is it possible to recover formatted data, are software solutions good enough to guarantee that all recovered data will be like before formatting? Is there a electronic solution to impr... |
H: Triggering a 555 timer IC
I need to trigger a 555 timer IC in astable mode as soon as it has power. It CAN NOT be done manually through a negative pulse like it usually is. The solution must be compact as space in my project is certainly at a premium. I either need a method of converting a constant high to a negati... |
H: GPS antenna ground plane design considerations and limitations
I have a PCB design which incorporates a GPS unit. I'm looking at refining the PCB, and I'm looking to do away with the long cable length, occupation of space within my enclosure, current consumption, and reliability issues that I have experienced with... |
H: How to wire centre tap transformer
I have what I think is a centre tap transformer with 0V and 230V inputs and 0V, 20V, 0V, 20V outputs.
Is connecting the two middle outputs to each other safe and will there then be a difference of 20V AC between the inner and each two outer outputs and also a difference of 40V be... |
H: What is the correct way to measure voltage with an optocoupler?
I'm using an optocoupler to measure a voltage, I'm making a current loop to control the current through the LED, so I'm using three op-amps: one to measure the voltage, one to set up a current offset because at very low currents the CTR is far from l... |
H: External GPS antenna for smart phones
Is there a smartphone GPS boost or external GPS antenna commercially available for smartphones.
To hook up to smartphones via audio input for example?
AI: It's not going to be possible to connect a GPS antenna to the audio port. You might be able to connect it to one of the te... |
H: Salient pole vs cylindrical rotor
Why is the salient pole rotor in a synchronous machine made of laminated steel whereas a cylindrical rotor does not have any lamination?
AI: Because in stator there is a AC flux and laminated steel construction minimizes the loss due to eddy currents, meanwhile the rotor flux is DC... |
H: PIC12F509 Not Blinking
Here's a relatively simple question: What is wrong with my code below?
I am trying to blink an LED from GP2 pin, but am getting confused when it comes to setting GPIO pins and registers, and its a bit different too because the 509 doesn't have an ADC. Would really appreciate some help.
Thanks... |
H: Shielded cables to capacitive sensor?
In a hobby project I am using shielded cable to connect capacitive sensor's electrode (see https://electronics.stackexchange.com/questions/189916/capacitive-touch-not-working-at42qt1011 ) to the AT42QT1011 (there are two cables ending with electrodes going in separate direction... |
H: BJT circuit with base emitter shorted
I was reading through Linear Technology's AN70 application note
and on Figure 40 there is a part of the circuitry that I can't understand.
It looks like a BJT pass transistor voltage regulator but instead of a Zener diode as a reference it uses a BJT with its base and emitter s... |
H: Electric light bulb burns out
Why electric light bulb more often burns out when we switch from OFF to ON our wall switch, but not during regular work? What happens to it so it burns?
AI: The sudden change in temperature from cold to hot is quite a violent thermal-mechanical shock to a light bulb. Of course you get ... |
H: Why can Ohm's law be used in a linear circuit with multiple equivalent resistors without being given current?
I'm exploring voltage dividers and am puzzled by the conclusion made by the YouTuber in this video:
"If you apply Ohm's law, you find that 1 V spread across two equal-value resistors gives you 0.5 V in the ... |
H: Self resonance frequency for MLCC capacitor
Is there a general self resonance frequency characteristics for MLCC capacitors? If I make a RC low pass filter, say using 1kohm and 15nF 0603 with fc = 10.6kHz, I guess it won't work as LPF beyond the self resonance frequency of capacitor. I couldn't find the self resona... |
H: Stepper motor for robot wheel drive
I'm trying to chose correct stepper motors to drive 2 wheeled robot. I started with geared DC motors, but found they are too fast (I have 27:1 geared), and they provide little torque at low speed.
Therefore I'm looking at stepper motors that will give enough torque at low speed. ... |
H: Programming a microcontroller with another microcontroller
I'm looking into using a PIC24FJ256GB106 to program three other of the same microcontroller.
So this is how it should work:
The program is sent across through serial to the master/programming PIC
That PIC receives it and uses ICSP to program the other PICs... |
H: Switching AC or DC signal via TCP/IP
What is the cheapest/easiest way to switch an AC or DC signal of at least 10 V via TCP/IP?
I have 5 measurement devices which can be triggered over an 0-250 V AC/DC input (switching threshold 10 V). The devices are set up in different power plants which share a common computer n... |
H: Choosing an alternate resistor or capacitor in a circuit
My question may look stupid but it's great trick in case of repairing in a battlefield.
When a resistor or capacitor gets damaged in a circuit and if the required value is not available then what should be the strategy.Choosing a high value or a low value,whi... |
H: Designing a boost converter
I am looking to design a boost convertor for a high school project and after doing quite some research I have come up with the following design.
I am looking to double my voltage. (Input voltage will most probably be 9 volts)
The left part of the circuit is an astable multivibrator and... |
H: Cutting power to IC using MOSFET fails
The aim of the circuit is to enable/disable power to an IC (U2) using a transistor (Q1) to enable/disable ground, controlled by an MCU (U1). However, when the ground is disconnected, it does not shut off the IC. I.e. U2 is behaving as it would if it was powered normally.
If th... |
H: Definition of differential input resistance
What is a differential input resistance (\$R_{\text{id}}\$) in a differential amplifier? Could you show me the expression for this quantity?
I think it is:
$$R_{id}=\frac{v_{id}}{i_{id}}=\frac{v_{i2}-v_{i1}}{i_{i2}-i_{i1}}$$
I didn't find this expression anywhere, so I ne... |
H: Construct OPAMP circuit for given inputs and output
Here is my task:
Construct circuit ??? which uses power supplies +12V and -12V and gives output voltage:
Here is circuit:
I solved it using 4 opamps:
First opamp scales V3, second integrates V4, third sums the results of the prior two circuits and fourth inverts... |
H: Accelerometer sensitivity range
I'm looking at the KX023 and it seems to have a 64 counts/g sensitivity.
Its datasheet specifies the following
What I don't quite understand is why there're two sets of figures. The top set goes up to 16k counts/g whilst the bottom goes up to 64 counts/g. 64c/g would seem very low w... |
H: Combining a 9v Battery and Bench Power Supply to power Opamp and circuit
G'day
I want to provide a few op-amps with +-9V. However I only have a single 9v battery. Is there any problem with dialling up 9v on my lab psu and combining them to get the +-9V?
I would use a voltage divider but I think I might have troubl... |
H: Keeping power on a capacitor after its charged?
I am building a capacitor bank. I have them soldered in already. My question is simple-ish:
Can I keep the power on while one capacitor is done charging? Like If i hold the charge button on for 10 seconds will it hurt the capacitor. Even if It is a slow possess but in... |
H: Help me find the device based on its label
I have an SMD component containing two pads (probably in a SMC case). There is a label on the surface of the component: fAC15 in one row and MP in second row.
I suppose the component is a Transient Voltage Suppression (TVS) diode.
Am I right?
Thank you very much for your... |
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