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H: Upper limits to chip size
This question on physics.stackexchange has an answer, which has a piece of information which is new to me:
Now, you could say "OK, let's increase the chip size instead". It turns out that it's also limited. Again, cost aside (pure silicon isn't cheap), the signals must be transmitted acro... |
H: Is the battery being drained?
I'm building a simple intrusion alarm system with a piezo buzzer fed by a 9V battery, I have a switch to activate/deactivate the alarm, and a trigger (like a switch) connected to a tripwire so if someone goes through the wire the alarm is set off.
My question is which of these configur... |
H: Is rms value of a positive varying DC voltage same with its mean value?
I know that rms of an AC is totally different than its mean. But what if the voltage is not alternating(DC) but varying by time. For example a noise with a huge offset.
How is varying DC measured by voltmeters? Mean or rms? Or as in my question... |
H: does this design look suitable for a 4-bit adder
I am working on a project that will include a basic 4-bit adder, I have designed a layout is Adobe Illustrator and would like people to check over it to see if it looks like it should work. I am very new to this side of electronics and don't entirely know what I am d... |
H: Deriving simple voltage equation
$$V_o = \frac{V_s \cdot R_2}{R_1 \cdot (1+R_2/R_L)+R_2}$$
I need to derive this equation given this circuit:
This is what I have so far.
$$I=\dfrac{V_s}{R_1+\dfrac{R_2 \cdot R_L}{R_2+R_L}}$$
$$V_{R_L} = I \cdot R_L$$
Where am I going wrong?
AI: If R\$_L\$ wasn't present the voltage... |
H: STM32F4 - Floating point unit ( FPU )
I would like to know, what is the purpose of the special FPU unit, that is advertised with STM32F4 microcontrollers ?
To quote this website :
" The Cortex-M4 core features a Floating point unit (FPU) single precision which supports all ARM single-precision data-process... |
H: Middle-Tapped Transformer Full-Wave Rectifier Vs. Full-Wave Bridge Rectifier
In terms of output voltage, which one of these would be best? Coming into this, I would have to say the center-tapped transformer full-wave rectifier would allow the most accurate output voltage (only 1 diode voltage drop).
I've always ... |
H: Audio from Arduino Due's analog outputs using LM386
Due's DACs provide 0-3.3v (actually less) and are rated at 3mA max. As far as I know, common speaker/headphone impedances range from 8Ω to a few hundreds, so driving these from the DACs will destroy it at best. I guess I could stick a series resistor, but it would... |
H: Audio from Arduino Due's analog outputs to line-in
Line inputs are high-impedance, Wikipedia says around 10kΩ. Due's DACs provide 0-3.3v (actually less) and are rated at 3mA max. \$\frac{3.3\rm{v}}{10\rm{k\Omega}}=0.33\rm{mA}\$. According to Wikipedia line levels are 0.316 VRMS for consumer-grade and 1.228 for pro... |
H: Simple broadband RF generator
How to make a generator of RF signal which have multiple signal outputs ?
Details:
Fout = [ F0, .., Fn-1, Fn ] , where
F0-F1 = F1-F0 = .. = Fn - Fn-1 = const 1000 Hz (i.e. constant stepping)
F0 is ajustable from 0.1MHz to 10MHz
n is somewhere about 100 steps
I can't use wh... |
H: What happens to a transformer if the supply side is shorted?
Suppose I have an industrial plant, where a switchboard is fed through a transformer. The switchboard have only "passive" loads, i.e. they don't contribute with short circuit currents.
If there is a short circuit on the switchboard feeding that transforme... |
H: Why is OCR1B values are not stored?
I have following program to control two servo motors:
#include <avr/io.h>
#include <avr/delay.h>
void main()
{
int x,i,j,t=0,y=0,n=0;
DDRA=0b11111111;
DDRC=0b11111111;
DDRB=0b00001111;
//Configure TIMER1
TCCR1A|=(1<<COM1A1)|(1<<COM1B1)|(1<<WGM11); //NON In... |
H: How to graduate from Arduino to using a microcontroller directly?
I've been working on an Arduino project. After I get everything working using the Arduino, I would like to move to a solution that does NOT use Arduino. That is, I would like to use a microcontroller without involving the Arduino board. This will all... |
H: STM32 Timer to control GPIO
I'm trying to output a slow clock (4kHz) on an I/O from the STM32F0. I'm wondering what the advantage is (if any) of using one of the timer pins to output this clock vs toggling another GPIO on the timer interrupts.
I was thinking I could do PWM mode with 50% duty cycle if I use a timer... |
H: Radio antenna isolating transformer
I need to isolate galvanically my antenna from my RF transceiver. For this I have been recommended a transformer, I select a 1:1 transformer operating in high frequency range. Is it enough to wire it in between the antenna and the transmitter, or we need to take more consideratio... |
H: In Eagle, why is the tstop layer larger than the pad itself?
Why is the tstop aperture around a pad larger than the pad itself? I would have imagined that it would be exactly the same size, or slightly smaller, so that the solder stays only on the defined pad. Would there be any reason to make it larger, or smaller... |
H: Lifting electromagnet & Induced EMF
An electromagnet is lifting/pulling large pieces of iron, from a distance $r$.
Is there an induced EMF in the coils of the electromagnet due to the change in flux?
Another configuration would be the piece of iron is rotating around the electromagnet is there still EMF induced?
I... |
H: Unipolar stepper motor and a MCU
I have been trying to steer unipolar stepper motor (5V, 0.7A) using microcontroller powered only by USB (5V or smthing like that). The motor clicking got louder but the motor doesn't move yet.
I tried to lower resistance of R1, R2, R3 and R4 and motor cliks got louder, but when I c... |
H: Heating and Chilling ICs instantly from 200C to 0C? Does it damage the silicon inside?
I soldered VCXO oscillator and suddenly tried to cool it down with a cooler spray. Do you think that sudden cooling and heating damages the chip. The heating and cooling were well within the spec requirement but I don't know if t... |
H: Controlling a DC motor speed with Arduino
I'm trying to follow this tutorial
But instead of the components specified in the tutorial, I'm using the following:
- RS-360SH DC Motor
- BD139 Transistor
- 1N4007 Diode
- 220 Ohm Resistor
I understand that the components are different than specified in the tutorial, but... |
H: What sort of a ferrite core will I need to make core memory?
I am building a homebrew computer using core memory. What sort of a ferrite core will I need?
AI: Look for a core that saturates in a low H field (lower power needed) and the core should have a wide hysteresis curve so that it stays magnetized when curren... |
H: What is the purpose of the Motor Run Capacitor?
Looking at a control box for a marine Air Conditioner and it has a HUGE capacitor in it. The schematics label it a "Motor Run Capacitor", but I always thought it was just used to start the motor.
What function does a huge cap like this have in running the motor?
The ... |
H: Making a three phase voltage source to drive a gyroscope
I'm trying to drive a gyroscope that needs a 3 phase 400Hz 32v 1A power supply. How can I provide that supply? It's one part of my university project and I'm a beginner in this field. I'd like to find the best way to provide a suitable supply.
thanks
AI: Use... |
H: Measuring AC voltage from DC battery
When measuring the AC voltage across a DC battery (CR2032), and I am getting 6v.
The DC voltage across it is 3.01 volts.
I also tested on a 9 volt battery; again the same thing. I am reading about 20 v AC and 10v DC.
I am using MASTECH MAS830L multi meter. I also used another mu... |
H: How does spread spectrum VCXO (voltage controlled oscillator improve EMI on your board?
I have seen people adding spread spectrum voltage controlled oscillator to EMI on the board, How is EMI affected by single spectrum crystal and with spread spectrum crystal.
AI: Spread spectrum improves EMI by spreading out the ... |
H: Soldering guidelines for freezer applications?
I'd like to do a home project where I take temperatures inside of my freezer and inside liquids. Liquid-compatibility aside, I'm mostly curious about whether or not anyone can recommend some best practices for the board design. I haven't found any resources online th... |
H: What are the typical qualification norms for assembly line workers?
My question seems OFF-TOPIC, but I do believe there might be people here(at electronics_stackEx) who know the answer. And I really don't know a better place to post this.
Here Goes the question:
What kind of education qualification do electronics a... |
H: What exactly is a potential barrier in transistors?
Here it says that:
When a transistor is OFF, there exists a potential barrier between the source and the drain..
I don't know exactly what a potential barrier is. If I had to make an educated guess, it would be a barrier that an electron has to overcome in order... |
H: Generating simple alert tone MCU project
A receiver part of my project should activate a light tor few seconds but they decided to add an alert tone which will be played on the PA sys of a building. I think input is 8 ohm imp PA. I was looking for an easy, fast way to implement a ability to generate an alert tone. ... |
H: Explain how this LED driver circuit will work - is there any way to turn on the LED?
Is there any way to turn on the LED in the below figure? You can apply different voltages at the diode input:
AI: It's not clear what the triangle with the circle is in detail, I suspect it's the output driver of a logic circuit (a... |
H: Is it a good idea to make one instrumentation amplifier with three operational amplifiers for thermistor sensing circuits?
Is it a good idea to have those three amplifiers with LM741 Operational amplifier? Has anyone done this so far? I thought of this as this was a cheapest idea. The instrumentation amplifier cost... |
H: Do you always need a GPIO expansion chip when using i2c?
SUMMARY:
I'm trying to learn the basics of understanding how to wire up a simple circuit using the i2c. I'm wanting to build just a simple project involving an LED and a push button with my raspberry pi. From what I understand the "pi" already is i2c capable ... |
H: Simple frequency deviation to voltage converter
I have a capacitive sensor connected to a 555 timer wired as an astable multivibrator and the free running frequency is 60kHz. When the capacitance of the sensor changes, the frequency of the 555 also changes. The maximum frequency deviation from the center frequency ... |
H: Fixing ATtiny45 Clocksource
I accidently changed my ATtiny45 clock source to 128khz . After that I can't program it . I tried avrdude in terminal mode but it doesn't work .
>>avrdude -P COM4 -c avrisp -b 19200 -p t45 -t -F -u
(I'm using Arduino as ISP for programming)
How can I fix it ?
AI: The ISP frequency can... |
H: Atmeg16 USART communication problem
In my project, I use a atmega16 to send data to PC via USB to TTL converter at baud rate of 9600 and internal RC of 4Mhz. If I power the atmega16 using my laptop through a usb cable I can receive the data perfectly, but when I power the same using a 9v DC battery and 7805 regulat... |
H: circuit analysis of DC-source, inductance and modulated resistance
Here's an interesting problem. Consider a DC voltage source (for bias), an inductor (supply wires, for instance) and a resistor, which changes its resistance as a function of time: \$ R(t) = R_{offset}+R_{mod}\cos(\omega t)\$, where \$R_{offset} > R... |
H: PWM with programmable Dead Time
I need to make a circuit that generates a PWM signal for a motor. The motor has 2 inputs - P and Q. They are the inverse of each other. Now, both signals aren't allowed to be high at the same time. That's why there needs to be a programmable Dead Time - the time between the signal th... |
H: How to ADD resistance with a push-button (Schematic Incl.)
Edit: New schematic, my apologies.
Background:
The circuit below shows a potentiometer "R1", which is not used until the normally open push-button "S1" is pressed. The second resistor "R2" is not used until the normally open push-button "S2" is pressed.
Th... |
H: How does installing battery backwards damage a torch?
Recently, I bought a high performance torch which uses a CR123 lithium battery. The manual warns against installing the battery backward and says it "will damage electronic components".
I recall doing simple circuitry at primary school, and installing a battery ... |
H: What is the equation for the 555 timer control voltage?
I was just wondering what the equation is to find the 555's output frequency is, when a control voltage is applied to pin 5. That would be very useful for me to know!
[Edit By OP]
So based on what Spehro Pefhany said, the equation for the output frequency (Sub... |
H: Floating EEPROM (28c64A) pins an option?
I am building an eeprom programmer for the 28C64A (dip package) with my old basic stamp ii "homework" board (lost my arduino in the move). I have the first four address and data pins, as well as W E and G connected from P0 to P10. I am working with what I already have, so bu... |
H: How to connect 120V to a relay on a prototype board?
I'm designing a microcontroller controlled switch. I idea is to have a 120V outlet controlled by time of day, or a motion sensor, etc. The plan is to have a lamp plugged into the outlet.
I will switch the 120V with a relay, which I plan to have on the same boar... |
H: Switching between several high power DC devices?
I would like to control several high power DC devices (12V DC LEDs). From a tutorial, I found that I can control these using a 3.3V PWM input and a MOSFET. From what I understand, the MOSFET only allows current to flow through the LED to ground when the PWM input is ... |
H: Comparator won't flip to HIGH
I am learning to use a comparator (LM393N) and running into trouble. No matter what I do, the output is always LOW. I am running off of a 9V battery, and I've added a voltage divider to send half of that to the V- (inverted) pin of the comparator. Yet, whether the non-inverted pin is c... |
H: convert self-powered speakers to passive
Is it possible to convert a self-powered speaker into a passive one?
(and if yes, how?)
My scenario:
I have an old pair of PC speakers i'd like to use with my portable MP3 player even if there is no power outlet nearby...
AI: Passive speakers like the Sony SRS-P7 are cheap h... |
H: Basic operation of a bipolar junction transistor
I've tried really hard to understand the basic operational principle of a transistor. I've referred to many books and been to forums but have never got a convincing answer.
Here are the things I want to understand:
A transistor is similar to a reverse biased diode u... |
H: H-Bridge ic not working as expected
Hi I am using the SN754410 h-bridge driver to try to control a motor using two switches. As I understand the SN754410 should be identical to the L293D. I have hooked up a circuit and I think I have followed this tutorial correctly, however when I try to use it the motor will no... |
H: SMD Connector type?
I am trying to find the connector type (see links below) for some time with out success.
The pitch is 1.25mm.
Also the "Shrouded Header WR-WTB" is really similar but the "key" is not in the center.Also the pins are closer to the pcb in my connector.
http://imageshack.com/a/img534/2446/s66h.png
... |
H: Terminating a 50 Ohm source into 1M Ohm oscilloscope input
Due to buying some equipment several months apart I am now faced with the task of connecting a high speed ,up to 1GHz, light detector that requires a 50\$\Omega\$ load impedance, but my oscilloscope only offers a 1M\$\Omega\$ input impedance.
Can I connect ... |
H: What to plug in first to usb charger when charging: wall outlet or cell phone and why?
I asked this question on Physics StackExchange but was advised to ask it here.
When I charge me cell phone or notebook or whatever device what should I plug in first? Should I at first plug in usb charger to the AC wall outlet an... |
H: How to detect how much battery power is drawn?
I'm programming a small device using a microcontroller. I'd like to optimize it to use less battery. How can I detect how much power uses over time as I run it through some tests?
Based on the tests I can optimize the code to use less battery life.
If I can't get an... |
H: Standing Wave Ratio(SWR) Measurement
I'm trying to find a way to measure SWR digitally. Generally SWR is measured with analogue equipments and it is not practical on self designed PCB. I did not find so much resource on how to do it digital way.
I have 10 Mhz hcmos oscillator which is filtered and converted to sin... |
H: How do I use a button to wake up an atmega32?
Sorry for any noobiness, I'm more of a software engineer.
How do I use button interrupts in general?
As in, if I put my microcontroller to sleep, I'd like a button to wake it up.
How should I go about doing this?
Edit
Adding this to main, thanks to @jippie
DDRD &= ~(1<<... |
H: ECG Shield electronic circuit explanation
I have this electronic circuit which is from a shield for the Arduino which allows me to collect ECG signals. However I do not understand what is happening. I am familiar with op-amps and amplifiers in general but do not understand this circuit.
There is a INA321EA (PDF) i... |
H: Karnaugh Veitch diagram and ordering of the variables
I have a little problem understanding the ordering of the variables at the axis.
For example, at the lecture we did 4 variable Karnaugh Veitch diagram as a
A
0 1 1 0
C 1 0
1 1 D
0 0 1 1
B
On this site I found it like this(page 5)
http:/... |
H: Charge at 24v and discharge at 12v for battery system
Is my thinking correct.
Below is a simple diagram of the concept I want to check.
Is this:
1: Possible
2: Feasible? I.E are there any concerns or foreseen issues with this design?
Edit:
AI: It will work fine as long as gray and brown wires are not present at th... |
H: What is the difference between Timer0 and Timer2 in AVR
I'm using ATmega32. This two timers looks very similar. What is a difference between them? When should I use Timer0, and when Timer2?
AI: Timer2 is async timer. It means it can count when sleeping. But it's tricky to setup it when external clock is required. W... |
H: Coiled wire around connector terminal, what do I call this, and how do you do it?
Please consider the following image:
I randomly wandered into the telecom room at work a while ago, and I noticed these strange looking terminals. How do you terminate a wire like this? Is there a certain tool to create the coil arou... |
H: At what resistance do I not see a voltage drop across a resistor?
If I have a circuit like this and measure the voltage drop across the resistor I get a value, regardless of what resistor I use:
However, if I stick a piece of wood in there instead of the resistor I get nothing. My intuition says there must be some... |
H: AC and DC voltage are constant even though the frequency changes
In the circuit below, why does the AC voltage remain constant even though the frequency increases?
AI: I can't see your circuit since the server in my university blocks the domain of the image hosting site, but based from your comment "I connected a m... |
H: How will I know the Power Efficiency of a load?
I have a thevenin circuit with a source load. How will I get the Pin and Pout?
AI: A Thevenin equivalent is a voltage source with a resistor in series like this:
For power to flow you need a load which is Rl in this schematic. The load at which maximum power is trans... |
H: What are class E amplifier RF choke guidelines?
I am designing a novel circuit that I beleive has not been constructed yet! No -- I'm just using an exotic switching device for a class E amplifier.
My operating frequency is close to the 160 ham band (my target is between 1 and 2 megahertz).
I have seen multiple desi... |
H: How to Calculate Appropriate R-2R D/A Converter Resistor Values?
I am trying to make a 4-bit R-2R D/A Converter where a +5V signal on D3 would output -5V, a +5V on D2 would output -2.5V, etc. How would the resistor values for R/2R be calculated?
AI: To a first approximation, the resistance R cancels out, however th... |
H: Should I use step-up or step-down transformer?
I am designing a 21" tablet using a development board, the development board takes 5V DC whereas the display takes 12V DC. The display will take around 800mA and the development board around 500mA.
I am wondering should I use a 12V adapter and Step-Down transformer to ... |
H: Effect of the high impedance or low impedance of oscillospe
I am measuring a sine waveform range 0 to 40MHz by using Agilent InfiniVision DS0-X 3034A. The data sheet of the oscilloscope is here: http://cp.literature.agilent.com/litweb/pdf/5990-6619EN.pdf
My question is when do we need to use low or high impedance s... |
H: What is the purpose of a filter consisting of a capacitor and two inductors?
I have the following filter in a single device:
It looks like a ceramic capacitor, but with 3 legs, and also states capacitance like such capacitor (only 103 printed).
What is the typical purpose of such filter? How would it usually be c... |
H: Will RF cause any health problem?
This is out of curiosity. I am working with rf 433 MHZ transmitter receiver module. I just wanted to ask whether it affects health in any way. I have read that such radiation has carcinogenitic effects. Does the power transmitted by the transmitter has any effect?
AI: There are two... |
H: Relay max current
I'm building a magnetic stirrer. I wanted to add a heated bed and I've been looking at peltiers as a heat source. To control the temperature I've identified the "WH7016K", a Chinese-made temperature control system designed specifically for direct peltier control and it's only about 20 bucks.
Howe... |
H: Design semiconductor device like CCD
I'm wondering if it is possible for an amateur (I have a physics background but not EE) to
Learn how to design something like the CCD or cMOS or LCD
Learn how to prepare the necessary files for the Fab (like TSMC) to produce my design
What is the best way of learning these? A... |
H: 3.3V signals to a shift register IC with a 5V supply
I have an SN74HC595N shift register that I want to have output 5V on the Q outputs. If I power it with 5V on VCC, can I tie the SER, SRCLK, etc. pins directly to the 3.3V digital outputs on my microcontroller? I wasn't sure if I needed a transistor between each m... |
H: RFID + permanent magnet
A project I'm exploring requires placing a permanent magnet in close proximity to an RFID tag (within a cm or so). Can an RFID tag be read when there's a permanent EM field so close to it?
AI: That really depends on your RFID technology and frequency range you are using.
With LF (125/135 kHz... |
H: Grounded thermocouple vs "grounded" thermocouple
I'm having problems with documentation and what appears to be conflicting use of the word grounded. The way I understand it, a thermocouple can be [grounded, ungrounded, or unsheathed] (http://www.omega.com/techref/themointro.html). But neither of the two wires are a... |
H: Max voltage input to microcontroller
I have looked at the spec sheets of this chip and it states that MAX Voltage on any pin with respect to VSS (except VDD, MCLR. and RA4) = -0.3V to (VDD + 0.3V). They also state that MAX Input clamp current, IIK (VI < 0 or VI > VDD) ± 20 mA.
Where I work our design actually has ... |
H: Problem with relay current requirement and how to increase current in DC circuit?
What is the minimum current required to run a relay of 5 V (part: RWH-SH-105D). Will the relay run with 5V DC and 0.8mA current (my inputs)? If it does not work, then please suggest methods to run the relay by giving suggestions on in... |
H: Rail-to-rail oscillations in subtractor op amp circuit
simulate this circuit – Schematic created using CircuitLab
Just bumped into a problem. When I am trying to make a voltage subtractor based on AD8055 op Amplifier, I get rail-to-rail oscillations/noise one the output.
The signal is 0.5sin + 1.5V at 1MHz. I wis... |
H: Does C-1602A-1YN LCD use the HD44780 controller?
I am new to using PIC microcontrollers and electronics in general. I have been reading a tutorial on how to interface a PIC with a HD44780 compliant LCD. As I have been shopping for a LCD I have been finding it difficult to tell whether a LCD uses the HD44780 interfa... |
H: Pocket AVR Programmer + PIC32MX
Is it possible (and how) to program a PIC32MX chip with a pocket AVR programmer?
AI: As delivered, no, because the AVR programmers are coded to assume the AVR SPI programming protocol, which is not compatible with the PIC programming protocol.
If you had enough hardware hacking to ch... |
H: Understanding max and min propagation delay in flip-flops
I've been working my way through Digital Design and Computer Architecture, but am very confused by the equations for time delay - what each of the variables are, and how to conceptualize these equations.
Assuming no clock skew, the book gives the following t... |
H: Any good suggestions for Basys2 optional oscillator 50 MHz or 100 MHz?
I want to get the optional stable oscillator for the Basys-2 but don't know which would be the best choice for 50 MHz and 100 MHz? Has anyone bought and used any? If so, what is the part number?
AI: Basys 2 already has integrated LTC6905 oscilla... |
H: 16x2 LCD not working with ATmega 8
Below program is written in AVR studio. Connections: PORTD pins 0 to 7 are connected to data lines of LCD i.e. DB0 to DB7 respectively, PORTB.1 connected to RS, PORTB.2 connected to R/W and PORTB.3 connected to EN of 16x2 LCD JHD 162A.
In program PORTD.7 is checked whether it is ... |
H: Need to know battery configuration for a 250 watts inverter
I have a 12 Volt inverter which have ability to produce 250 W output. I would like to purchase a battery for this. can any one tell me the configuration of battery ?
eg: Minimum AH
AI: Ball park figure calculation.
Assuming an 80% efficiency
... |
H: Can Arduino power and hookup to logic chips?
I am making a device that has two external interactions i.e. a button and a infrared sensor. My only problem is that I am using a logic chip for this because it would save me time coding on the Arduino, but now I don't know if the Arduino can cooperate or power the OR CM... |
H: Is it safe for micro to switch pins from input to output in a loop?
I'm trying to make use of a keypad that I took out of a phone which has 3 columns and 4 rows. I've traced out the schematic on its PCB and figured out a way to drive it that I think might work, but I'm not sure whether it's safe for the microcontro... |
H: Level-triggered flip-flops in shift register
I am studying shift registers. My book mentions that level-triggered flip-flops cannot be used to make a serial-in serial-out shift register. What is the reason for this?
AI: If you use level-triggered flip-flops (without a two-phase, non-overlapping clock) then all of t... |
H: What does this IGBT data sheet mean by "transient" gate voltage?
I'm using IXGH45N120 to discharge some capacitors. The gate voltage is derived from the capacitor voltage, through some resistors and a zener. The circuit has worked fine for a long time, many hundreds of discharge cycles. We've recently had cause to ... |
H: What reasons are there to avoid vertical through-hole resistors?
I'm working on a layout for a PCB and I need to include a handful of pull-up resistors. The board I'm working on will be a proof of concept, and it is likely I will only need one (and order two). That being said, I'd like to keep the board area small.... |
H: It is it possible to safely use a 110V variac (variable transformer) at 230V?
I've come across a variable transformer/variac which is designed to be used with 110V input. Our line supply here is 230V.
If I was careful not to exceed the VA rating of the transformer (920VA) would it be possible to safely use this ... |
H: MOSFET discharge (turn off)
I am using the IRF9321 P channel MOSFET for controlling my BLDC motor.
The MOSFET is driven via a transistor which in turn is run by a freescale controller(3.3V pin). Now, when turning it on, it works fine. But, when turning it off its a disaster with the MOSFET taking almost 5ms to com... |
H: Design of a 1-bit adder-subtractor with additional carry/borrow input
I have to design a 1-bit binary adder/subtractor unit that can both add or subtract two input values A and B depending on a control input C (it is assumed that two's complement is used).
Also, the adder/subtractor has an additional input \$C_{in}... |
H: Supply noise due to Motor
I'm currently trying to install some IR sensors on an Arduino robot and am having issues with the sensor readings anytime the motors (2 of them) turn on.
I'm using an Arduino Uno connected to an Arduino Motor Shield. The IR sensors are Vishay IR detector modules powered from the regulated ... |
H: Not getting input on STK600 with ATmega8515
I recently had a written exam for a class and one of the questions was to write a program for the ATmega8515. I wrote down this:
#include <avr/io.h>
#define F_CPU 4000000UL
#include <util/delay.h>
#define Delay 5000
int main(void){
DDRB = 0xFF; //set to output
DDRA =... |
H: Charging of Cell Phone Batteries and Electricity!
Does charging an already charged battery of cell phones/laptops consume electricity?
Whenever my cell phone becomes fully charged while charging, it asks me to remove the charger from the socket to save energy.
I was wondering why would a charged battery consume en... |
H: Do servo motor specifications take into account the gear ratio inside?
I know this question may not belong here but I assume this is most likely where the most well informed people can help me.
I am looking at buying a servo motor for a an application that must be able to lift 4-5 lb at a rotational speed of approx... |
H: Find product lead dimensions
I am building a project for a robot on breadboard, and I have come across the need for a voltage regulator. I have an existing voltage regulator, but it will not fit into the holes on my breadboard. As a result I have begun to look for a new voltage regulator that will fit into my bre... |
H: How do I increase (multiply) the value of a current sink?
I have been shown an IC that is a current sink PWM dimmable LED regulator. It happens to be a WS2811. While this works well for low drive currents (up to about 20mA), I was approached with the idea of making it drive power LEDs (~1 amp @ 3 volts).
I immediat... |
H: I need to use some sort of component to boil water inside of a container that will be triggered by an arduino signal. How?
I'm trying to build a prototype for my own coffee machine. It'll have a container of water that will need to be boiled when a signal is sent by my arduino. The question is, what component shoul... |
H: How can I model a variable current sink in spice?
For a project I am working on (related question here) I need to model a nonideal variable current sink in spice.
Simply reversing the orientation of a current source or inverting its value is not sufficient because it is still sourcing current, just in another direc... |
H: Circuit abbreviation: GND, MIN, TRANS, etc?
I am originally a programmer, so I am not quite experienced in circuit symbol and abbreviation. I receive a custom made 2-in-1 Light photo diode receiver + Current-to-Voltage converter from my professor and I'll have to write microcontroller program to receive data from l... |
H: Get location data for a program using GPS dongle
I'm working on vehicle tracking system using GPS. What I want to do is connect GPS receiver to my laptop and fetch the location data in to my program. I have seen many commercial GPS receivers and dongles. Those devices providing there own driver software. Is there a... |
H: Making an Android accessory that supplies more current to Android Tablet
I'm making an android accessory that uses a PIC microcontroller and a FTDI FT312D chip to poll a bunch of sensors and then report the findings back to a nexus 7 tablet.
Although I am using a 4A power supply, the tablet is not getting enough cu... |
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