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H: Do you need to solder the center point in this type of BGA chip?
I have the following chip. I'm not sure if its called a BGA chip or not. I need this chip replaced and I'm able to remove it using a hot air station, but I would like to know if I require soldering the center pad that is underneath the chip. Is this p... |
H: Schottky diode part of a laser power supply enable circuit
In this circuit from Jim Williams' AN90 the enable line pulls down the base of Q1 through Q2, through a Schottky diode (1n5712). Why is this Schottky diode there? I imagine it's a Schottky diode so it has a diode drop smaller than Q1's, so it's possible to... |
H: LMR16030 voltage regulator circuit
I am trying to set up a circuit to use the LMR16030 buck regulator to step down 60V to 9V. I bought the Powergood version and I'm not sure how to connect the power good pin.
As you can see in the datasheet on page 3:
http://www.ti.com/lit/ds/symlink/lmr16030.pdf
"PGOOD pin for Po... |
H: minimum spacing between hobby circuit board edge and DIP IC
Since I don't run a labratory and I have a standard printer capable of printing 600 DPI, I'm trying to make a small circuit board but I'm wondering, whats the closest I should place the pins of a DIP IC to the edge of a circuit board?
My normal track sett... |
H: What do these deprecated markings mean?
I found this Moog Prodigy synthesizer schematic that I'm trying to figure out how it works in order to learn more about how electronics work.
What do the circled symbol at the top of the schematic mean ?
What does "N.C" mean ? An example of it is located at the far right.
Wha... |
H: Supernode with 2 voltage sources and 1 current source: node voltage analysis
I'm struggling with defining a super node in this case. My initial thought was to create a super node with V1 and V2, but I'm not sure how to handle the current source. Doing KCL in this configuration would mean that the current source can... |
H: Why are there no BGA chips with triangular tessellation of circular pads (a "hexagonal grid")?
Ball grid arrays are advantageous integrated circuit packages when a high interconnect density and/or low parasitic inductance is paramount. However, they all use a rectangular grid.
A triangular tiling would allow π⁄√12 ... |
H: Why is VGA connector has only one pin for red color data but is composed of 8 bits?
VGA connectors have 15 pins, three of these are used for color data of red, blue and green. Based on this project, each color has a width of 8 bits. However if under the scheme of 8-bit color, each color will have 8 bits of data. (U... |
H: 2.4 ghz RF radio and antenna - nrf24 underneath a 7-segment display
I have this tiny nrf24 module that I want to use underneath a 7-segment display.
How much will this affect the range and the quality of the radio signal?
I have done a lot of research and testing on this other similar nrf24 module. Mostly abou... |
H: capacitive proximity sensor - how does it work
I know 3d printers such as the i3 use a Capacitive proximity sensor to try compensate for the uneven surface of the print bed. for example this one seems to be popular
https://www.amazon.co.uk/gp/product/B00542U3M4/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
If am not... |
H: Fourier serie coefficients of real function
Let's take a periodic wave function defined by f(t) = (1 - t) with a period of 1.
The Fourier coefficients can be calculated:
$$
\omega_0 = 2\pi/T=2\pi \\
F(n) = \int_{0}^{1}(1 - t)e^{-jn 2\pi t}dt=-\frac{j}{2\pi n} \\
F(0) = 1/2
$$
There is a property of Fourier series ... |
H: is soldering mobile processors something that i could do at home?
I want to connect a mobile processor such as a Samsung Exynos or Qualcomm Snapdragon, which both have their connectors on the bottom to a PCB but im not sure if this is something i can do on my own or needs a pick and place machine, to be honest im n... |
H: Has anyone used partsim and if they have, where is the potentiometer?
Thanks you all for reading. Lately I have been trying to use www.partsim.com to model a vintage synthesizer in hopes of building a real one with real hardware. However it's really expensive to do so and I don't know anything about electronics so ... |
H: Understanding microcontroller ADC input pins (atmega328)
If I set up the ADC on the ATmega328 to read from a certain ADC pin, what state is the ADC pin put in to?
Since I don't explicitly enable any pull ups, is the pin floating/high voltage/low voltage?
AI: Since I don't explicitly enable any pull ups, is the pin ... |
H: What happens with a diode and a battery in this circuit?
What would happen if I have a battery and a diode in a circuit with the diode trying to force the negative part of the battery to the positive part? Just wondering...
simulate this circuit – Schematic created using CircuitLab
AI: You would have a somewhat fu... |
H: Help with converting scheme
I have this scheme and I can't make it look normal in order to count total resistancce
AI: So it doesn't look like you want us to solve it for you which is the reason I am helping. If you had wanted it solved for you, you would have provided values.
my guess is perhaps you just want to l... |
H: Is it possible to import a netlist from Multisim into Kicad?
So at the moment I'm using two different programs for modeling circuits. Multisim and KiCad. I use Multisim because it allows me to do SPICE simulations, something that KiCad doesn't allow me to do. I then need to route the circuit on a PCB, something tha... |
H: Passing Voltage above threshold
I am trying to design a electronic circuit which will only pass voltage between a threshold, like a dual clipper.
The input is a varying DC input and the system (would) allow output only above 3.3V.
Initially I tried to design a negative clipper with bias voltage but then the bias vo... |
H: Crowbar circuit with TL431 help
So I'm trying to create a OVP using TL431 an a triac, i have checked the datasheet but since i suck at math i don't really get how to set the ref voltage..
datasheet: http://www.ti.com/lit/ds/symlink/tl431b-q1.pdf
My example circuit:
I'm having a 19v power supply, and i want to make... |
H: Capacitor output differentiation issue
I am an electronics student and today we were looking at the voltage output of a charged capacitor against time, which can be modelled in relation to R, C and e (I forget exactly how) but our teacher then differentiated it to find the gradient and it confused me because it was... |
H: MOSFET switch circuit design feedback
I would like to have some feedback on this circuit.
V1: 0,6A Solenoid
V1_LED: Arbitrary small LED
V1_IN: Input signal from Arduino (3.3V, 20mA)
Should I change something?
Is the IRLML2502 suitable? Is there a better choice?
Edit:
Link to MOSFET:
http://www.infineon.com/dgdl/i... |
H: How to safely measure a 480VAC waveform with a DAQ?
I have a LabJack U6 Data Acquisition unit and would like to measure 12 (4 sets of 3 phase) 480VAC lines simultaneously at 600 samples/second. This would be used to evaluate a 480VAC 3phase, generator and utility system that has intermittent brown-out and black-out... |
H: Resistors soldered 1cm off board
I've got a 8 year old pair of powered studio monitors that have recently started hissing for about 5-10 minutes after being powered on from being completely off. The culprit was some bad caps that I am replacing. While I was at it, I noticed that there are two large resistors coming... |
H: Applying KVL to DC bias calculation
I'm trying to use Kirchhoff's voltage law to find the bias point of a bjt amplifier circuit, as shown below:
I begin with switching off the signal and opening all capacitors
simulate this circuit – Schematic created using CircuitLab
The transistors are identical, both with beta... |
H: Will this PCB trace GSM antenna be affected by EMI?
I am designing a PCB in which there are 3 SIM800 GSM modules sharing a (commercial) external antenna. The external antenna is connected to the PCB via an antenna connector, and from that connector, the antenna signal is “shared” via PCB traces running to the GSM_A... |
H: LEDs and voltage optimisation
I am looking for some advice.
I understand that LED drivers transform a supply from AC to DC as well as the amount of volts from input to output, for this reason i believe they are classed as inductive loads.( these are not inductive, these are non-linear resistive loads)
Will there be... |
H: Intel i7 Core CPU numbers on the front side
What is the numer at the fourth row on the front side of Intel i7 CPU? (pictured)
I saw two Intel CPUs in the store described as "Core i7-6700" but have slightly different prices (both OEMs). Only the difference I found is the numbers on the front side.
P.S. I'm already ... |
H: Technical term for smooth scrolling digital volume encoder
I am making a bluetooth volume control from a machined aluminium billet.
I cannot find a technical name for the digital volume encoder that would provide that smooth rotation.
Or am I approaching this wrong and should be looking at smooth analog pots and t... |
H: Why gmbs is not zero when B and S are tied together?
I tried to run this simple circuit for DC operating point. The transistor is in saturation with Vth = 800mV.
What makes me confused is about gmbs.
It is not zero but also very large compared to gm.
Why gmbs is not zero when B and S are tied together?
Thank you.
... |
H: Algorithm for testing EEPRM
What are the steps or the algorithms to verify that an EEPROM is working ?
Right now I just write 10 bytes and I read 10 bytes from 10 addresses, and that's naïve approach. Is there an algorithm or an approach to verify that the eeprom is correct ? or also the problem for flash memory ... |
H: How do I assemble this using the following circuit?
I'm a third year Computer Science student and have decided to create a pulse sensor for my third year project. I'm mainly interested creating software to visualise results but I thought it would be cool to attempt to actually build the device also.
I'm attempting... |
H: Any better way to determine source of light by analyzing the electromagnectic spectrum of the light
Project overview
I am tasked to develop a microprocessor based device that when shown a light upon, can determine the source of the light (Natural light, Flourescent Bulbs, LED Bulbs, Incandescent Bulbs, Flame - Fore... |
H: Questions and confusions on transmission line theory and lumped element model
I want to model a simple signal transmission system by considering it as travelling through a transmission line.
Here is the system:
The original signal generated by the transducer is 0 to 10V step function like signal with very low 3Hz ... |
H: Transistor Switch Maximum Permissible Resistance
I have been learning from a series called "The Great Courses". This is a question that modifies a given example with new numbers. No matter what I do, I cannot reach the correct answer, and the book gives no explanation.
The image is a little messy but all given info... |
H: Confusion about the rated voltage of a Permanent magnet synchronous motor
Confusion about the rated voltage of a Permanent magnet synchronous motor.
I’m currently trying to do a motor control experiment and I’m really confused by a term called “rated voltage” from the motor specifications.
Below is my Simulation sc... |
H: bi-directional half-duplex communication between two AT89C2051's micros without serial port
I'm trying to do a direct two-way communication between two AT89C2051 microcontrollers with only two GPIO pins so that I have other GPIO lines free for other tasks.
P3.7 is the data wire, and P3.2 (INT0) is the control wire... |
H: Adding Slab to a Capacitor
I was solving a question in an Electromagnetics book and need some help: two parallel plates were connected to a 100V battery. The battery was removed and then a slab of dielectric material was placed between the plates touching the upper one but leaving 0.25 mm of free space in the botto... |
H: Why can't I find Phase to phase voltage like this
I know that that in 3phase ac,
Vll = sqrt(3) * Vln
I got confused about the sqrt(3) part so I draw phaser diagram and the resultant vector will give me the phase -phase voltage
But it only gives me 230V , why?
Can anyone explain how it got sqrt(3) in equation??
A... |
H: Hardware sources of entropy on an FPGA
I'm building an FPGA feed handler and one of the problems is I want to do Monte-Carlo simulations which require a high-quality entropy source, i.e. a pseudo-random LSR implementation won't do. I've read that one can try using metastability as a source of randomness, does anyon... |
H: Would this be a legal VHDL architecture?
I want to design a basic BCD to XS3 converter using VHDL. I am fairly new to
conditional and behavioral architecture implementation, but I was wondering if this would be a legal program, especially my assign statements
entity bcd2xs3 is
port (bcd : in std_logic_vector(3 ... |
H: How to add part in eagle board that doesn't have corresponded in the schematic "jumpers"?
I am using Eagle to design single side board and I want to use smd jumpers to connect between some points.
So basicly I don't want to add those smd jumpers as a component to the circuit in the schematic, I just want to be able... |
H: connect headphones to TV RCA output?
My TV has two RCA female connectors for audio output. I assume it is the line-out. No female jack connector specfic for headphones.
I want to connect usual headphones that has a male jack connector. I've buy an adapter "two male RCA => one stereo jack" (Y-cable) and everything s... |
H: Boolean Algebra with Demorgans Law
I have to prove that:
!(a(b + z(x + !a))) = !a + !b(!z + !x)
I am assuming that I have to use DeMorgans Rule so this is as far as I'm getting with:
!a + (!b!z + (!xa))
I'm not sure where to go from here. More specifically I'm not sure how to get rid of the a in (!xa).
AI: !(a(b + ... |
H: What kind of transistor do I use for switching high voltage with a microcontroller?
I am working on a project with Nixie tubes which require a high voltage supply. I have some "indicator dot" tubes that require 90V DC, and I want to turn them on/off using a microcontroller control line.
I am thinking a transistor i... |
H: How do you apply the negative feedback laws when there are two feedback networks?
I have the following circuit, which has a series-shunt feedback in the form of r3 and r7, and a shunt-series feedback in the form and r4 and r6.
How do I apply the usual steps in analysing negative feedback amplifiers, then? For exam... |
H: Bridge rectifier peak voltage at load
Assuming the peak voltage at \$V_1\$, \$V_{1p}=9.25V\$ and ideal silicon diodes (\$0.7V\$ drop in forward bias) and the DC output in \$V_0\$ is \$5V\$. I want to find the \$V_{op}\$, peak voltage at \$V_0\$. Given that the ripple voltage, \$V_r=0.2V\$ Then:
\$V_{DC}=V_{op}-\fr... |
H: Best way to hand-solder this TQFP (SMD) component
So I'm working on a small project right now that requires a ATmega32U4RC. I'm trying to test/prototype with it, but it's a surface-mount component, so I can't just place it in my breadboard. So I found this, which is perfect for what I want.
The problem is that I h... |
H: Why negative feedback (common source degeneration) increases linearity range?
From this online lecture (page 190-20), I see that the negative feedback (Rs in common source degeneration) helps increases linearity range.
I am wondering if anybody know an explanation for this intuitively or mathematically.
Another qu... |
H: How can earth fault meter work through inactive IGBTs
I have a setup with a Bender IRDH375 connected to the DC bus of an IGBT based inverter. If I connect a 50kOhm resistor to earth while running the inverter, it detects it well. That part is reasonably ok to understand. However while not running it still detects a... |
H: Relationship between voltage/current & LED strips?
I recently bought a WS2812 LED strip (5 meters, 300 LEDs)
When the LEDs are driven at full brightness and each color lit, they draw 60mA each--or 18 amps for all 300!
This led to a problem, which led to a question.
A friend suggested that I not attempt to power th... |
H: Why microcontroller takes many clock cycles to start up with PLL clock source?
I was looking over the ATTiny85 datasheet and noticed on page 26 that with a PLL clock source, the fastest startup time is 14CK + 1K (1024) CK + 4 ms. Am I misinterpreting what they mean by 1K CK, or is it that the PLL needs time to set ... |
H: How are RS 485 transceivers implemented?
I would like to know how transceivers (which are used to send and receive differential signals) are implemented. AFAIK the receiver the transmitter (TX) could be something similar to an H bridge. I already took a look at datasheets of some popular transceivers but I could n... |
H: Digital gain control with a digital pot?
I want to make an audio amplifier with digital volume control. I figure that by adjusting the feed back path that I won't change the input impedance and won't affect the frequency response. (other than the gain bandwidth product)
Does the following setup look reasonable?
W... |
H: Determine the current i through the 4 ohm resistor
Due to different frequencies, i applied superposition by shorting the right source
and applied voltage division rule to get the voltage across the resistance.
Vr=3 ∠0° * 4/ (4 + 6j) = 1.666∠-56°, and Ir=Vr/R
But the answer is not correct (for the right source also... |
H: Triangular wave generator
As part of a college project I have to design a working Class-D audio amplifier.
One of the first challenges is to generate a triangular wave at a frequency arround 100kHz.
In order to do this I have in mind generating first a square wave (using a 555 timer in an astable configuration) and... |
H: Specification of DC motor
I have a motor, like to use it for a project. I don't have the specification details of it(volt, Amps, RPM). Can someone help me in this regard?
Image source/Item description
AI: This motor is manufactured by Mabuchi. The part number 'RK-370SD-4045' actually tells you quite lot about it... |
H: Finding value of Resistance for Maximum Power
I am badly stuck in finding value for R in this circuit for maximum power transfer in the network,
It is my assignment question and I am badly confused.
Please help ,
Thanks.
AI: For maximum power transfer you are expected to not only know how to set up equivalent ci... |
H: Set the threshold voltage of CMOS inverter to VDD/2 for both rising and falling edge: possible?
Using 0.35u technology (VDD= 3.3v, Vt=0.7, Tox = 0.7 nm), I am trying to set the threshold voltage of an inverter to VDD/2.
If I set the width ratio of PMOS/NMOS to 5 (means the Width of PMOS would be 5 times larger tha... |
H: Is it a good idea to connect aluminum AC mains wires by soldering
Provided I have an appropriate flux for aluminum and I'm able to solder the wires will this connection be durable?
I'm not sure if it will corrode or not considering aluminum and the solder (60-40 solder) are different metals.
AI: Provided I have an... |
H: Can I apply nodal analysis if the wire doesn't have a resistance?
simulate this circuit – Schematic created using CircuitLab
How do I apply it in the wire containing D4 and D3 if it doesn't have a resistance? The way I learned is: \$\frac{V-V_{D4}-V_{D3}}{R}\$ but in this case there is no resistance across \$V\$ a... |
H: Fried motherboard resistors, what to do?
A motherboard failed under load recently, and here is the worry:
I am waiting for a new mainboard. What must i do about it? is it a very easy repair? I am mostly confused about identifying the resistors.
AI: These a filtering caps on one of many of platform voltage rails. C... |
H: Use external reference for frequency counter
I recently bought an HP 5316A frequency counter. It has the ability to use an "external reference". Does that mean it ignores its internal clock and uses the external signal in lieu of the clock?
Is it complicated to provide the external reference signal? What is involve... |
H: MAT12 matched pair transistor substrate connection
On Analog Devices' MAT12 data sheet, there is a note (see on the top right, note #2) saying that the substrate, which is connected to the case, is usually connected to the most negative circuit potential. Since there is no pin connected to the substrate (or to the ... |
H: 12v battery reading 10.7v not supplying 5v load
I have a solar charge controller connected to a solar panel (30w), also connected to the charge controller are a 12v battery (4.5Ah) and a raspberry pi Zero (5v, draws approx. 200mA).
This evening the charge controller is showing the battery voltage as 10.7v.
I turn o... |
H: How to measure the input impedance of a summing amplifier?
I have a summing amplifier set up like so, and I need to come up with a test to find the input impedance, I know because its a 741 IC that it will be in the region of 250k - 10 mil ohms, but don't know how to test it and explain the test results
AI: Anythin... |
H: Random signal lost or extreme weak signal with remote controller on ISM frequency (433Mhz)
There is a task given to me that I have to investigate a problematic RF remote controller against its weakness and make a suggestion report how it can be improved.
This RF remote controller is used with two hands like PS cons... |
H: Jacob's Ladder and Component Identification
What would be the component in the bottom left of the picture?
AI: It looks like an option for 120/240 primary windings. My guess is it is connected in series for 240Vac operation.
The arc generates ozone, UV and other nasty EMI, not for newbies. |
H: Use superposition to find voltage V1
I first open circuited the 50 mA source and used Ohm's law to find \$V_1\$
$$V_1= 20 ∠0° \frac{j50 \times (-j25+40)}{j25 +40}$$
but the answer is not correct. Also, how do I find \$V_1\$ when the 20 mA source is opened?
AI: (a) The circuit across the active current source is ... |
H: How can I tell if my building plumbing provides an adequate ground?
I work in an old building with two-wire wiring, i.e. no separate ground. Is there some minimum-equipment-purchase way to tell if a wire soldered to a building plumbing pipe is an adequate ground? I have a standard hand-held multi-meter.
AI: http://... |
H: Confusions on FFT of a square-wave in theory and in scope and simulation
Below is an ideal square-wave in time domain, and its harmonic components in freq. domain:
As you see above a square-wave is composed only of its odd harmonics as spikes nothing in between.
And below is an oscilloscope's FFT of a square-wave:... |
H: Comparator input offset voltage
This is an example about input offset of a comparator in Analog Integrated Circuit Design by Tony Chan Carusone (page 414).
Could anyone explain why the plot in Fig 10.1 is a normal distribution?
AI: There are two parameters in a Normal Distribution, the mean and σ, the standard dev... |
H: Connecting the linear regulator directly to AC line
There are several out of the shelf solutions: LR8 from Microchip (formaly known as Supertex product) and NCP785 from ON-Semi. The last one is able to handle up to 700 volts at the input which is impressive.
Both components is very attractive to be used in my appli... |
H: LDR not detecting light from LED when finger placed between the two
I'm currently working on a project which uses an LED and a photoresistor to work out my BPM.
I have a schematic which I've built into a prototype which all works fine and when I run the serial monitor in Arduino I'm getting output values.
The pro... |
H: how to improve RF meter?
On https://www.rfsafe.com/product/diy-rf-meter-led-powered-rf-detector-diodes/ , there is a kit which contains:
nine 1SS86 Schottky diodes and
one LED,
which uses to detect mobile phone and microwave radiation.
It states:
range of application: mobile phone GSM signal. It is useless for ... |
H: How to control a device that need to be updated over internet?
I know, the question is very vague, but I'll try to explain better.
I'm working in a school project and I got interested in continuing this project after school. It's a automatic aquarium. I want to control everything that happens in a aquarium, so I us... |
H: Should I use a current limiter on a battery powered system
I'm designing a small battery powered system, actually I'm battery powering a module which already has all the switching regulators it needs. This provides me with a wide input range of 5-10V. I was thinking of connecting the batteries directly to the mo... |
H: Addressing issue in flash M29W800DB
I wanted to loop through the addresses in that flash M29W800D, so I started a counter from 0 to 0xFFFFE, then I try to write an unsigned int to an address, but it fails. When I made the loop counter to increment each even addresses, it worked.
but why ? what's so special with tha... |
H: Supercompilation for electronic design
I'm reading Advanced FPGA Design and the first example, one of simply raising a number to the 3rd power, quickly diverges into various quite clever optimizations to make the valuation faster.
Now, personally, I'd argue that such minutae is best left to the computer, so my ques... |
H: interfacing buttons with python/c++
As a preface: I have 0 experience in interfacing with peripherals other than keyboard and mouse, but am willing to learn, just don't know where to start.
I would like to write a software in python (if C/C++ would be needed or is the easier way to go I can interface that) running ... |
H: Selection of DC Motor Drivers
Is there different Motor Drivers available for Permanent Magnet DC Motor and Wound Rotor DC Motor .Specifically for Series and Parallel wound DC Motor .
AI: Yes. A brushless Permanent magnet DC motor requires a controller that switches the polarity of the voltage applied to the winding... |
H: Schematic Numbering Scheme
I need help determining what are some helpful bits of information to include in a new schematic number scheme. For example:
Schematic ID
Revision (Major, Minor, Fix)
etc.
Its not critical, but I would like to define some good info to include in the numbering system before I commit to it f... |
H: Use of diodes and resistors in a push-pull amplifier
What is the function of the two resistors (R4 and R5) and two diodes (D1 and D2) in the circuit below?
AI: The diodes keep the bases of the transistors 1.4V apart. This reduces crossover distortion. The resistors are to provide a bias current for the diodes.
So... |
H: power for the load in push-pull amplifier
I wanted to ask:
what is the power needed for the load resistor?
Is there any problem? and what might be the solution for it?
I really appreciate you help, thank you!
AI: 2) The circuit in your other question is the improved version of the one in this question.
Let's tak... |
H: Capacitor charging circuit review needed
I recently posted a thread about using a coin cell to power an electronics project that features an SD card (here). The problem at hand is that the SD card will pull high current during read/write operations, much higher than a coin cell can handle. However, the fact that th... |
H: Issues with using higher capacitance than required
http://www.digikey.ca/product-detail/en/stmicroelectronics/LD1117V33/497-1491-5-ND/586012
I am planning on using this regulator for a home project. I noticed on the datasheet that a minimum 10uF capacitance can be used. On the design diagram, they also have a 10uF ... |
H: How to Add SRA to a MIPS One Cycle CPU
I'm trying to add the MIPS command SRA to the following one cycle CPU:
If I knew how many bits needed to be shifted I could easily replace the lower bits with 0's, but that's never a known till the instruction is being executed. What would be a way to implement this so it doe... |
H: DC motor control ULN2803
I'm trying to do some basic DC motor (pump) control through an Adafruit Feather Huzzah (ESP8266) and an ULN2803 Darlington transistor array; I've wired it up as follows:
And my code goes a little something like this:
void setup() {
Serial.begin(9600);
pinMode(14, OUTPUT);
analogWrite... |
H: Measuring small capacitor parallel to big inductance (Network Analyser)
So what I have at hand is a cheap network analyser that can present the measured impedance in form of the values of different equivalent circuit topologies, e.g. R-L series or RL parallel.
What I want to do is measure the electrical parameters ... |
H: Laser for Engraving & Cutting
Can I use 500mw 808nm Infrared IR Laser Diode for engraving and cutting of wood, plastic and metal?ASER
https://www.banggood.com/Focusable-500mw-808nm-Infrared-IR-Laser-Diode-Dot-Module-12V-TTL-Fan-Cooling-p-1227542.html?rmmds=search&cur_warehouse=CN
AI: No. 500mW at IR wavelengths ca... |
H: Input of boost converter or charge pump in the energy harvest
I read some paper about the energy harvest, and lots of paper said the induced voltage from, for example, the thermo-electric harvesting could be as low as tens of millivolts in a realistic case, so their input of boost or charge pump is less than 100 mV... |
H: Daisy chaining a large number (20) of TLC5940 in serial. Bolstering signals?
Working with shift registers (tlc5940 and Library) on Sparkfun breakout boards driving individual LEDs.
The boards are designed to connect VPRG, GSCLOCK, BLANK, XLATCH, SIN/OUT, SCLK,VCC, GND in serial. Everything works perfectly on Board... |
H: Using a capacitor instead of a coil for wireless charging?
This might sound like a stupid question, but I'm kinda interested in a detailed explanation.
So while inductive charging is rather ubiquitous, things like electric toothbrushes and Qi chargers come to mind, as well as to a lesser extent, wireless charging p... |
H: Difference between push-pull and totem-pole
I can't understand/see the difference between a push-pull and a totem-pole output.
Push-pull:
Totem-pole:
Do these circuits have a transistor in the input for something like "double amplification?"
AI: You'll notice in the push pull stage that you need a PNP and an NPN ... |
H: How to improve design of naive MW AM transmitter for lab demo
I'm trying to prepare small demo for school lecture on radio history.
sorry for confusion, MW here means medium wave, not megawatt :)
And I want to create small and very simple transmitter which could be "heard" with old factory built receiver. There are... |
H: Creating Light Sensor
So the situation is like this, I have a project with a budget of $25. I have to build a robot that is capable of connecting a magnet to a tin can autonomously. I also have a vex kit which I can use for free. I need to create a system so that the robot can find the tin can and drive to connect ... |
H: Getting a Constant Value From ADC
I run a 10bit ADC from which I get a number which varies in-between +/-5.
Ex:- if ADC value is 512 then it may vary from any number in between 517 and 507.
I do not want to use any filter mechanism as it is computationally intensive.
I just want to get a pick a fixed number from la... |
H: Why 2 zero-crossing detection circuits in heater?
I reverse engineered the power board of an electric heater. I think, I understand most aspects of this circuit. One thing is not entirely clear to me though: The circuit seems to have two distinct ways to detect the zero-crossing point which is needed to control the... |
H: Adjustable brightness for IR remote signals
I'm using and Arduino, an IR Led, and a transistor to for sending RC5 signals (36khz).
For the next step I need to be able to adjust the brightness of the signal, basically changing the range. The value could be set by an analog signal, spi or i2c or anything basic.
I tho... |
H: Lithium Ion Battery Pack - Looking to calculate watt-hours from V1 to V2
I've got a 2S4P Lithium Ion 18650 pack (that's 2 sets of 4 cells in parallel where each set is in series).
These batteries can be changed to typically around 4.1 or 4.2v and can technically be discharged low (2.5v), however the wider this ran... |
H: Implementing a Mealy Machine in Verilog
I have a piece of code that I don't understand:
always_ff @(posedge CLK)
state <= RST || ~A[0]===1'bx || ~A[1]===1'bx ? 0 : nextstate;
A is the input. What is this piece of code exactly doing? What is ~A[0]===1'bx or ~A[1]===1'bx?
My guess is that this code is checking if e... |
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