text stringlengths 83 79.5k |
|---|
H: Simplifying opamp+thermistor circuit
I asked this question yesterday, which got answered and would work, but as I already stacked up on (dual) opamps I might as well do better.
I've come up with this (probably flawed..) circuit, to amplify/convert 98 to 140 Ohm thermistor output across the whole 0-3.3V range for my... |
H: NTE912 Pinout Confusion
The NTE912 contains three standalone BJT transistors and two configured as a differential pair. The datasheet can be found at
http://www.nteinc.com/specs/900to999/pdf/nte912.pdf
and gives a pin configuration that looks like
Short of hooking the chip up and using trial-and-error to see what... |
H: Controlling throttle valve with PWM and TIP120
I'm trying to achieve this. He's using a darlington transistor, so I started looking for an appropriate circuit. I've made that, with a TIP120, using a 1k4 resistor (instead of 1k) and a 1N4007 diode (instead of 1N4004). But I do not believe that those two changes shou... |
H: Board to board connection cable
I have a project where there are 2 board to be connected inside of a metal shielded chassis:
1) 2 layer power/analog/ext connector (usb/spdif/audio)
2) 4 layer digital board (lcd+mpu+fpga)
The board (1) will be placed at the edge of the metal chassis, while the other will be at the t... |
H: pci express bifurcation - clock fanout buffer needed to split reference clock?
I am designing for a motherboard with a single PCIe x16 slot which can be bifurcated into 2 logical x8 slots with jumper settings. I am designing a board to handle the physical splitting of the port.
The manufacturer of the motherboard ... |
H: How can I offset and scale a differential voltage signal
I have an HCPL-7840 isolation amplifier. It's input side is connected to some high voltage (~300V) power circuitry.
It produces a differential output signal that is nicely isolated from the power side. Each of the two pins that form the signal are between 1.2... |
H: Designing a mixed signal circuit for the first time
I am designing my first mixed signal circuit. I will then have a analog and digital ground plane and my question is:
To be able to have separate grounds (analog and digital) on a battery powered device, one would have to have two batteries? One that powers the ana... |
H: Looking for some solar panels to go with this project
I've been looking around for some solar panels for a little homemade solar phone charger project. I recently found a portable phone charger project from a student at Cal Poly which I'm hoping I can add solar panels too instead of using batteries. I'm wondering t... |
H: Wood workbench as ESD protection?
ESD protection are really expensive for hobbyist like me.
I have a grounded wrist strap but do you think a simple non-treated wood workbench surface can replace a really expensive ESD tabletop ?
AI: A good part of ESD safety is dissipating the charge in a controlled manner. If the... |
H: Understanding Electrical Engineering with Analogies
Understanding concepts with analogies help can be a useful technique and hopefully this will help me better understand electricity and Electrical Engineering better.
Lets start with a simple water example:
X volume of water starts flowing from a collector (batter... |
H: RFID system for insect tracking - range of reading
I am planning on conducting an insect-tracking experiment in the field. We are going to have square enclosures (15m x 15m), where our insects can move around freely, but will not leave the enclosure. We want to track each individual (around 50 individuals per enclo... |
H: What does 1.0 It current mean?
A datasheet of Li-Ion battery states "The current should be maintained at 1.0 It or less". What kind of unit is It?
AI: The datasheet has a 'Glossary of Terminology' which includes the definition of lt.
Represents "Current" and is defined as follows It(A)= Rated Capacity (Ah) / 1(h).... |
H: Wind direction measuring circuit
I have some difficulty to understand the schematics for the following anemometer: http://www.fondriest.com/pdf/rm_young_05103_manual.pdf
I have confusion at 5 points.
Here is the schematics:
In the manual it states: “Avoid a short circuit between the wind direction signal line and... |
H: What is the difference between a tuner and an antenna?
I was just told by my TV's customer service that my TV had a tuner but no Antenna as a response to my question - Can I use my TV's inbuilt Antenna to pick up over the air channels?
I was wondering if someone can elaborate on what the differences between these a... |
H: How IC encoder ΤΧ-2, encodes signals?
I 'm trying to figure out the way IC encoder ΤΧ-2, encodes signals. The procedure, if I am correct, is:
Receives input data (DC signals).
Generates digital pulses, via an internal oscillator.
a. in case of RF transmission, frequency is at: 128 KHz
b. in case of IR transmission... |
H: Using a Zener diode to ease a voltage regulator
I was reading a tutorial on how to hook up a zener diode to ease
a voltage regulator. Here if you follow this link, as one can see the zener diode is dropping
some amount of voltage to ease a voltage regulator: http://www.flickr.com/photos/oskay/6683456487/
My questi... |
H: Need +9V power supply for breadboard (3x Stepper motors). Tried Arduino wall wart
I need to supply +9V to three stepper motors on a breadboard with driver carriers (see parts below). Its too much for my raspberry pi to handle, apparently. I was able to power and control a single driver, so I know my setup is good. ... |
H: Relevance of amperage in a voltage divider circuit
I'm not very competent on the electrical engineering, so forgive me if this is a dumb question.
I'm trying to make a voltage divider circuit to monitor the battery level of a project I'm working on. It utilizes a 12v scooter battery and will be monitored by an Ard... |
H: Any more subtle alternatives for LEDs to indicate status?
Is there a low-cost, less annoying alternative to a buzzer or LED for displaying the status of an operation? I want my clock radio on at night, but it has this really annoying power indicator LED.
I'd like to keep some form of power indicator, so replacing t... |
H: How does the iso work in ccd\cmos array detectors
I'm curious to know how exactly does the iso sensitivity work in ccd's or cmos detectors that DSLR cameras have? I understand this is a amplification of the raw signal that each pixel has, but is in amplified before digitizing it or after? Can this be accessed manua... |
H: Resonance factor of RLC circuit
Say we have a RLC circuit, connected to a source. Say, regarding to the positive side of the source, we have in order, an inductor L, followed by a resistance R and a capacitor C in parallel. So we have L in serial with R || C. My question is ...
How could I calculate the resonance f... |
H: Correct use of Flyback or Snubber diode across Motor or Transistor?
From seeing a few schematics where the flyback or snubber diode has been placed across the transistor C-E terminals (Right Configuration), instead of what I typically seen as the the flyback being placed across the coil terminals (Left Configuratio... |
H: What does the following Verilog code realize
I was learning verilog hardware description language. I was confused a bit with the blocking and non-blocking statements. Can someone tell me what the following verilog codes realize and simple hints how
always@(posedge clk)
begin
q1=d;
q2<=q1;
q3=q2;
end
alway... |
H: Diode small signal model and exponential model comparison
I'm working my way through the chapter on diodes in Sedra and Smith Fifth Edition
Exercise 3.15 asks:
Consider a diode with \$n=2\$ biased at \$1ma\$. Find the change in current as a result of changing the voltage by \$(a) -20mV (b) -10mv (c)... \$ etc. In ... |
H: Slow PNP turn-off time, how to optimize it
I'm multiplexing a pair of Nixie tubes. The high-side control is done with two pairs of transistors, MPSA92 high-voltage PNP to switch the 160V to the tubes, and a BS108 to control the base of the PNP:
simulate this circuit – Schematic created using CircuitLab
(R2 represe... |
H: Voltage divider but don't know current requirement, so how to pick the ratio
I want to connect my little RS232 to TTL converter to a 5V power supply but the converter needs 3v3. So I thought, even with my very little electronics knowledge, I could knock up a potential divider to do this...
... on considering it I r... |
H: Problem Reading PIC18F4550 Input
Hi I am facing some problem with Reading the input from a PIC18f4550 , for a simple arrangement where when a switch on (switch = 1), few led should glow., and on releasing the switch the led should go off (switch = 0),. On providing some volts across a pin (RA0 or RA1)- the leds sho... |
H: What is the use for non-inverting input resistance in a negative feedback opamp?
Here in the Figure R5=50K.
This resistor value is not in the equations to obtain output voltage, and in many tutorials non-inverting input is directly grounded without a resistor. What might be the reason to use it here?
AI: R5 equals... |
H: How is a varactor diode used in a circuit when it only has 2 terminals?
I've been reading about varicaps, and I'd like to try to use one in an op-amp integrator circuit to be able to adjust the gain.
My confusion though is that every varactor diode datasheet I've read indicates that only 2 pins are used, like a no... |
H: MCP23017 in series
I have a hand full of MCP23017 (16 bit multiplexers/ I/O Expander) but I can only get 8 IC on the bus due to the limit of address but I need 200 pins (about 13 ICs) for a 8*8*8 RGB cube
and was thinking about and wondering what issues I might have if.
A. changing the addresses of the IC actively ... |
H: AC small signal analysis of BJT nework
Why do we set the input voltage to zero (short circuit) when calculating the output impedance of a transistor network?
Why don't we set the output voltage to zero (short circuit) for input impedance calculations?
AI: This is a reasonable question and the answer is straightforw... |
H: Recognizing low-pass filters
Does the capacitor in this circuit serve as a low-pass filter?
The premise of the circuit is to be a small SD card based music player. The write
up, Simple SD Audio Player with an 8-pin IC, says that it is necessary to filter the PWM output with a low-pass filter. I believe this is us... |
H: ATtiny 85 io High Voltage
I've search all over to no success. I tried the data sheet, but couldn't make heads or tails of it. What is the voltage of an output pin of the ATtiny 85 when high? is it just the same as the input voltage a vcc? Also, what is the maximum current output when run at 3.3v?
AI: This is from t... |
H: Gain in Common Emitter Amplifier
I need to design an amplifier having a Vin=150mVp, 1khz; Vcc=3V that can run an 8ohms, 0.25 watts speaker, with a gain for about 7 without noticeable distortion.
Below is my designed voltage divider biased common-emitter amplifier with Vin=150mVp, 1khz; Vcc=3V.
But here is my concer... |
H: Updated. Extending Range of a microstrip antenna with a SMA 2.4GHz Omni Direction 20db wifi antenna
Dear all I have the bellow A2DP bluetooth module which has a zigzag microstrip antenna. I want to extend the gain in the antenna with my 20db wifi antenna.
I know as far as that I need to scrape the majority of the ... |
H: Android to arduino- best board option for wireless
I'm a novice arduino hacker. I need to connect a hacked Android to an arduino wirelessly but unclear as to which option is best. I've read about the Mega ADK and it is my understanding that a regular board (uno?) can be used with a wireless bluetooth dongle.
What i... |
H: Using open collector as regular 5v output
I'm trying to use the following IC: SN74S289BJ so that the output is 5v when HIGH and ~0v when LOW, however I'm having problems due to the open collector nature of it, as I've written data to a specific address and the transistor won't sink the pull-up current (meaning that... |
H: Bluetooth4.0 vs WiFi in a Android to arduino connection
I've read this article
http://gtms1313.wordpress.com/2013/04/01/bluetooth4-0-vs-wi-fi-direct/
which is a good summary of latest Wifi vs Bluetooth technologies, but the actual hardware being used needs to be taken into account. I need to hack an Android which ... |
H: Basetech bt-153 issue
So I've just received my first bench power supply and she seems like not working. But As it's my first I'm perhaps doing something wrong.
First test, I go to continuous voltage, set it to 0V. Put the negative probe of my multimeter in the ground output and the positive to the +V output. Set t... |
H: Send a frequency impulse when switch is active
I'm a newbie when it comes to electronics, so please forgive any glaring mistakes!
I am trying to create a simple circuit that sends an audible frequency/tone to a line-in/mic input when the mercury switch is active. Could anyone help me to identify what component I wo... |
H: Motor bridge no longer responds to lower voltages
I'm making a circuit that I used for a previous project on a bread board to power two electromagnets. I'm using the same wiring and parts as the first time. It's a simple circuit using an Arduino to control a motor bridge.
Here's the problem: when I try to operate ... |
H: Which software is used to design this Cirucit?
Could you help me with the name of the software used to design the circuit below?
I have used Eagle (Easily Applicable Graphical Layout Editor) but I want to design my circuits with looks something like this below.
AI: The software is ExpressPCB. This software includes... |
H: Effect of emitter bypass capacitor
I am studying BJT frequency response, particularly low frequency response, and I am not getting a clear picture of calculating the effect of an emitter bypass capacitor.
My question is: why is the impedance looking through capacitor not simply like this:
$$ [(R_S //(R_1//R_2)) + ... |
H: Measuring power with a current transformer
I'm working on a project at the moment to measure power through a current sensor.
I posted a similar question before, and received very helpful advice which I have tried to heed.
I have improved the design (I hope) by incorporating a precision rectifier.
I still need to ge... |
H: What is the hardware/device that can switch a 5V and 12V (simultaneously) PC power supply lines?
What I want to do is to switch the power supply lines (5V and 12V) for a hard drive. The 5V line is meant for data transmission, and the 12V is for the spinning disk DC motor.
I would like to control the hard drive powe... |
H: Clocked edge-triggered timing (contamination delay)
I'm reading a book about computer architecture, and it says that, in clocked edge-triggered devices, the contamination delay is usually nonzero, and that the contamination delay for registers is assumed to be greater than its hold time, "giving it the important pr... |
H: Isolate wires soldered on PCB
I'm soldering some cables on a PCB. They are are stranded, so I've first apply a bit of soldering on them and then solder them on my pcb.
The problem is, there's on some a bit of exposed copper on the basis (1 or 2 mm) and they are soldered really close.
For now I don't have any short ... |
H: Help me identify this type of pin header
Can you help me identify this type of pin header?
I know it's a SIP (single in line) package, but would this type of connector be male or female since it has both gender types of connectors?
Also, could anyone suggest a distributor to purchase this type of header in bulk?... |
H: Control toy car transmitter with Arduino Uno
Could someone suggest how I would go about soldering the necessary wires to a toy car transmitter so it can be connected to the pins of an Arduino Uno to allow the Arduino to control the car - forward, backwards, left, right. Could I solder wires to the pushbuttons conn... |
H: What are the dangers of cutting PCB with Dremel?
I'm cutting PCB's with a Dremel. Works really fine at high speed and with the finest cutting wheel. Can get really nice and clean results.
There's a lot of project and dust so I place next to my third hand a large PC fan at maximum speed oriented to the opposite of m... |
H: Inverting interrupt edge (STM32 wake up pin)
A sleeping STM32 can be woken up by a rising edge on its wake up pin. But if the IC on the other end of the line only interrupts as falling edge, is it possible to invert it somehow ?
AI: Yes, the WKUP pin works like that. If you really need standby state, you pretty muc... |
H: Wire-tie cables
Is there a name / specific type for flat-jacketed wires which come tied on consumer product cables (eg. earphone cables, power cables) ? I always collect them from the new products I buy, but I wish to buy some in a volume.
I find it the most handy thing (rather than nylon zip ties) to temporarily t... |
H: How can we measure sinusoidal signals in atmega8 ?
How is the signal frequency measured in ATmega? In particular, how is the signal frequency (sine) measured in ATmega8?
AI: Sample values using an ADC with a minimum frequency which needs to be twice (more is better ;-) the frequency you expect your sinus to be. The... |
H: Correct USB to RS 3.3 / 5.0 logic level cable
I am starting with electronics / arduinos / atmegas here. For a couple of recent days I've played with USBasp programmer, atmega328P MCU as well as with 7805 and LM317 voltage regulators. Now my next step is to try to talk with DS18B20 temperature sensor and then with R... |
H: 1100 Sequence Detector
I have to design a 1100 sequence detector using Mealy model and JK Flip-Flops. Here is the state diagram:
And based on this diagram, I obtain following input statements for flip-flop inputs (A and B flip-flops):
JA = A and X
KA = B
---------------
JB = A xor X
KB = A nand X
Finally, VHDL im... |
H: Finding the thevenin resistance
The task is to find the thevenin equivalent (seen form terminals a and b) of the following circuit:
I believe I have found the thevenin voltage by simply finding the voltage drop over the 5 ohm resistor, which is in parallel with the 5A current source (if there is a better way to ap... |
H: How do DC motors work with respect to current, and what consequence is the current through them?
Motors in general have always been a difficult subject that I cannot fully wrap my head around. Considering DC motors, what determines the rate at which the motor spins?
It was my understanding that a permanent magnet ... |
H: Opamp relaxation oscillator (single supply)
I simulated and built current circuit.
What I got was a rectangular wave generator with a duty cycle significantly lower than 50%.
Than I made R3 = R4 and got 50% duty cycle.
I managed to think that RC constant is defined only by C1 and R1.
It appears I was wrong.
How c... |
H: How do I calculate battery life for my devices?
I want to power coupe devices via car battery, but before I do that I want to figure out how long battery will last.
Most of the devices work from 5V so I am using 12Vto5V converter (link to item on ebay)
The convert powers RaspberryPi, Arduino Pro Mini, and usb hub&d... |
H: Accidentally used plumbing flux on a PCB; How do I remove it to reuse the board?
Two weeks ago, I picked the wrong tub of flux from my toolbox and used it for making a 9VAC -> 5VDC adapter. I fluxed all the components and soldered it down before realising I was using PLUMBING flux!
The solder pads are all still int... |
H: Debugging an RTD-to-ADC conditioning circuit
As a software developer, I got myself into a bit of a pickle trying to make a 3-wire Pt100 temperature probe readable by a 3.3v microcontroller's ADC pin.
I followed page 4 of this MCP document which describes how to do exactly what I'm trying to do, and breadboarded eve... |
H: Problem with Arduino UNO and RC servo
This is my first attempt to work with a servo and I'm using this tutorial. I have a "TowardPro MG996R DIGI HI TORQUE" servo directly connected to my Arduino Uno as follows:
I also created the following code to upload onto the Arduino:
#include<Servo.h>
Servo myservo;
int s... |
H: Help Understanding an Autonomous rectifier
Could anyone tell me how does the circuit below work ?
It's a autonomous rectifier. Taking the signal between the two output resistors gives a full-wave rectification, and taking it at the output of the second operationnal amplificator gives an half-wave rectification.
... |
H: What is the best approach for reducing harmonic distortion?
I have a power system where on some buses, large converter driven machines result in high harmonic distortion. As far as I know, there are mainly two ways to reduce the harmonics.
A filter to remove (reduce) unwanted harmonics within a range of frequenci... |
H: Stored energy (and others) of RC circuit
In a circuit shown below me and a friend of mine discussed how we could calculate this.
simulate this circuit – Schematic created using CircuitLab
He simplified the circuit by stating the resistors and capacitors are in parallel, and hence it can be simplified to a capacito... |
H: Accuracy vs Precision
Does it ever make sense to have more precision than accuracy? E.g. if you had a variable resistor which you could control with a resolution of 0.01 ohms but your multimeter only had 1% accuracy, then that extra resolution would be pretty useless wouldn't it?
AI: Absolutely. There are many appl... |
H: Multiple voltage regulators?
I have a 12V DC voltage and need to draw around 1A at 1.2V. A quick calculation gives me the following results:
\$P_{dissipated} = (12V-1.2V) \times 1A = 10.8W\$
That's huge!
Can I use multiple regulators like 12 to 9, 9 to 7, 7 to 5, 5 to 3, and 3 to 1.2?
That would give me the follow... |
H: From 5v to 3.3v at from 8mA to 160mA
I'm working on an arduino project. The arduino have a 5V output up to 500mA and a 3.3V output up to 50mA. The problem is i have to power several circuits under 3.3V who consume between 8mA and 20mA each. 8 circuit maximum, so 160mA max. So I can use the builtin output to power t... |
H: How to check if a comparator is broken?
I have just started experimenting with electronics and am concerned that I may have destroyed my LM339 comparator circuit. As a basic test, I had a 3.0 volt power supply hooked up to the Vcc pin and one of the + input pins. Nothing was hooked up to the corresponding - input p... |
H: AV.link dongle (SCART's CEC)
I am looking for a device I can plug into an old TV's SCART port, which will feed me remote control commands (like 'arrow-up', 'OK', 'menu', etc.) received over the SCART connector's AV.link (control bus) pin in a usable way.
By "in a usable way" I mean in a form that is usable by a com... |
H: Microchip, memory measured in IEC?
It doesn't say on the data-sheet, but I'm curious where i can find if Microchip uses IEC or SI as standard for there memory sizes.
For example:
http://ww1.microchip.com/downloads/en/DeviceDoc/21754M.pdf
The Microchip Technology Inc. 24AA512/24LC512/ 24FC512 (24XX512*) is a
64K... |
H: Ultrasonic transducer response to harmonics?
Does anyone know offhand whether an ultrasonic transducer will respond efficiently to harmonics of the fundamental? For example, will a 40kHz transmitter also transmit with reasonable efficiency at (say) 20kHz or 80kHz?
AI: A standard piezoelectric ultrasonic transducer ... |
H: How to reliably and safely recreate a blue smoke monster for a workshop?
First and foremost, I'm going to say that I do and plan to continue to follow all safety best practices for working with electronics. I'm also a relative newbie, so I don't have a lot of experience diagnosing WHY things fail, and especially no... |
H: Reason for anvil and post in LEDs
Is there a reason for the anvil and post in a LED having the shape they do - other than making it easier to distinguish between the anode and cathode?
AI: Both wires are placed symmetrically with respect to the LED's axis. The die is also placed on the axis. Therefore the cathode w... |
H: AM demodulation circuit
From the receiver circuit below, which is exactly the part that demodulates the RF signal?
I know, a typical circuit used for an envelope detector is composed of a resistor, a capacitor and a diode. Is that similar?
I' m a newbie and any help would be appreciated.
AI: The demodulation is don... |
H: How does one estimate the electrical power of a power plant?
I've asked several people how a power plant creates power (i.e. currents and voltages) and I found that they were unsure. In addition, I’ve done several searches to get more information, and I was not able to find links to answer my questions. I am very f... |
H: Maximum *charging* voltage for Li-Ion battery
I'm implementing a CC-CV algorithm for charging a li-ion battery. I'm confused what is the maximum allowed charging voltage during CC (constant current) phase.
All application notes and datasheets, I've found state that charging in the CC mode continues until cell volta... |
H: Creating a small scale bumper car ground power grid
I'd like to build a tiny RC car that can run indefinitely without the need to charge. Bumper cars have strips of power on the ground and according to Wikipedia this is how they work:
"Uses alternating strips of metal across the floor separated by
insulating sp... |
H: Finding the amplitude response of an LTI system
I'm asked to find the amplitude response of an LTI system described by the difference equation:
$$
y[n] - ay[n-1] = x[n]
$$
After taking the Fourier transform of both sides and some math, I get the frequency response:
$$
H(e^{jw}) = 1/(1-ae^{-jw})
$$
But how d... |
H: I2C on PIC12s using MPLAB x (win7) and XC8
I am from a programming background, but very new to microcontrollers. Pardon me if this question is very basic, or doesn't make complete sense. I'm trying to bootstrap my knowledge, and the learning curve appears to be steep in some areas.
I am trying to get I2C working ... |
H: Parallel NOR Flash ROM in-system programming issue (Micron M29F160)
I'm attempting to program a Micron M29F160 Flash ROM (datasheet) that is memory-mapped into a larger system, and I want to program it from the external interface of that system, but I can't seem to get it to work. I have had success programming th... |
H: Altium footprint Wizard SOT669
Anyone know if the footprint wizard in Altium can be used to generate SOT669 package footprints?
It appears to me that its only capable of 3 lead MOSFETs. I searched the web and couldn't find anything, I don't mind making footprints by hand but its a standard form factor and I'm a li... |
H: Removing solder effectively
I have an Epihpone (Les Paul 100, fairly standard) electric guitar, which over the years have gotten to suffer from a non-functioning bridge pickup. I verified this using an ohm-meter, the result being that only the neck pickup gave a signal (also apparent from plugging it into my amplif... |
H: What's wrong with my Comparator (Hysteresis)
My intention is to design a comparator to be used to sense the voltage change in the sensor. Exploring further into comparator's I got that, I must implement Hysteresis to avoid unnecessary switching and use the design in harsh environments.
Below is the circuit diagram... |
H: Solve for power over a resistor
I'm studying for my final and the instructor isn't in for questions.
I'm stuck on a practice exam problem.
No calculators are allowed and I don't expect that nodal or mesh analysis will be required(though it's not out of the realm of posiblity, he's never had any problems that requir... |
H: Measuring water pressure in a tank
I am trying to build a pressure sensor ( PSI gauge ) that will be used to measure and monitor the pressure in a pool water filter. These generally have a mechanical pressure gauge like this....
What I want to do is use this Freescale Pressure Sensor so that I can electronically m... |
H: ICD3 + PIC + MPLAB: Target Device ID 0x0 does not match expected Device ID
We designed a board with a Microchip PIC24HJ256GP610A on it. We've successfully used an ICD3 to program and debug the PIC on the Explorer 16 development board. We think we've followed the design guidelines found in Debugger's User's Guide:
... |
H: Why isn't my SysTick_Handler() being called in my LPCxpresso C++ Project?
I have created a C++ project for an LPC1227 using LPCExpresso 6.1.0. The project, up until now, builds and runs fine. I have not made any changes to cr_startup_lpc12xx.cpp.
I would like to add a SysTick_Handler(). In my main.cpp I have add... |
H: Prototyping an antenna array receiver
Disclaimer: I am decent with math/theory, but I have zero hardware knowledge (apart from some basic microcontrollers).
I'm looking to build a (possibly crude, but functional) hardware prototype of a receiver with an antenna array. The application involves frequencies in the 2.4... |
H: Could 8V of power be safely put onto the 3V3 input of an Arduino Uno?
I have permission to access a (borrowed) Arduino Uno, and the documentation says it can be powered with 3.3 Volts from the 3V3 pin:
3V3. A 3.3 volt supply generated by the on-board regulator. Maximum current draw is 50 mA.
http://arduino.cc/en/M... |
H: What is the difference between JTAG and EJTAG?
I want to know what is the difference between JTAG and EJTAG? I know about JTAG as it's a hardware tool used to examine the memory and registers. Correct me if I'm wrong.
AI: JTAG is more than examining memory and registers, see EEVBlog 499 - What is JTAG and Boundary ... |
H: What effect does selecting the wrong load capacitance for a crystal have?
I've seen questions such as this one and this one that talk about selecting capacitors that, in series, match up as closely as possible to the load capacitance of the crystal.
What effect does selecting the wrong capacitance have? Does it ske... |
H: Can anyone explain this high-frequency "alien voodoo black magic"?
I was casually watching Mike tear down a spectrum analyser (13:30 is the relevant part, 16:50 is the awesome part), and he came across what he aptly described as "weird messed up alien voodoo black magic stuff":
As a layman, I can only nod in agree... |
H: Op-Amp Design Resistor Values vs. Actual Values - Gain Calculation
I have created the following differential op-amp circuit with the aim of converting a 0-3.28V analog signal into a -10V to +10V output. I have calculated the gain required 3.28/20 = 6.1
From looking at differential circuits the gain is equal to the ... |
H: Logic analyzer: multiple circuits, one ground
I will receive soon my first logic analyzer but I'm wondering something:
There's only one ground on the analyzer. What if I want to measure at the same time two circuits with two separate power supplies? Can I just use one ground? Should I bridge the two grounds togethe... |
H: Water Sensor to detect backed up drain pipe?
Trying to detect when a drain pipe, filled with water from a washing machine pump, starts to get backed up.
Since the water is being pumped through, a simple water detector is not enough. And since the water is being pumped and draining, but slowly (Too much water volume... |
H: Calculate Resistor Value for Optocoupler - 24VDC Anode
I'm looking for help and unfortunately stuck for time on a project, so hoping someone wouldn't mind helping me out.
I am trying to calculate the resistor value required for an opto-isolator circuit. I am powering a 24DC magnetic reed switch passing ground throu... |
H: Calculate rated power(P) of transformer?
I have a transformer-type PT 13/2/6 as the following page (Versions 34 to 37 from 68). Image like this:
The voltage between points A and B is V AB (primary)= 230 vac
The voltage between points C and D are V CD (secondary 2) = 6 Vac
The voltage between points E and F are V ... |
H: Logic level converter for H-bridge and UART for Raspberry Pi
Here is my situation:
I'm using a raspberry Pi to control a H-Bridge. The H-Bridge is not tolerant of both it's inputs being high logic value, which causes a short through the transistors, bypassing the motor. Because the H-bridge requires a 5V input, I s... |
H: GPS accuracy problems outside vs inside with repeater
I have an interesting problem testing GPS receivers:
While working inside our lab, we get reasonable results. We have a GPS repeater, as shown in the picture.
Inside the lab, I get good accuracy (between 3m to 5m error). On the roof, I get more than 10m errors.... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.