text stringlengths 83 79.5k |
|---|
H: DC motor accuracy with encoder
I am building a coil winding machine and I've already set up something that works. I used two nema17 stepper motors and tb6600 stepper driver cards. The problem is that motors are seems to overheating when I make them work at low speeds. Internet says it is okay for steppers to overh... |
H: What is the minimum die area of a chip?
Silicon chips are made by slicing up wafers; in general, the fewer transistors a design needs, the smaller the area it needs, so the more chips you get out of a wafer, and the lower the cost per chip.
But there must be some limit to this. Maybe you can have a chip of one squa... |
H: Strange powering of the TL710 comparator
I have an old schematics of 80th fancy synthesizer VCO. It uses the TL710 comparator, that according to the datasheet has -7V Negative Supply Voltage. I cant find the emitter-base breakdown voltage of EN5179. For me, it looks like it is used as a Zener diode. The EN5179 is ... |
H: Inductor coils, core, and a gap between
I am speaking, here, not in the more usual sense of a gap in the continuity of the core material. I mean, in reference to a rod of core material, that the outside diameter of the rod is sufficiently smaller than the inside diameter of the coil, that a uniform separation exis... |
H: infrared and K-Type temperature sensors badly disagree
They are both cheap. There is a piece of PCB balanced on top of the K-type thermocouple's probe; there is also a red laser light from the infrared thermometer right in the middle of the same PCB where the probe's head can be seen. The difference between the rea... |
H: IRLZ44NS mosfet + 3.3v gate
I'm considering using some IRLZ44NS mosfets that I have with an ESP32 that runs at 3.3v. Looking at the datasheet it says:
VGS(th) - Gate Threshold Voltage - min: 1.0v, max: 2.0v
It seems like this will work, but I saw some other posts that refer to people using these mosfets unsuccessfu... |
H: How to calculate kWh from amps
I'm getting measurements from an IoT device.
This measurements are in amps (I get one every 2 min or so).
I know the voltage of the device.
From what I've seen online I can calculate the power in kW doing
\$P = I * V / 1000\$
Is there any way from this information for me to calculat... |
H: Can I turn on a relay OUAZ-SS-105 from high on P26
Is it possible to turn on a relay OUAZ-SS-105D using a high on pin 26. See image
Case 1: if I replace the P26 connection with a wire to vdd the led "GOES ON". The vdd voltage is 3.3 volts.
Case 2: if I apply a high to P26 (which reads as 3.3 volts as well) the le... |
H: Why are Alkaline, NiMH, and Li-ion AA measured differently (mAh, mWh, etc)?
Looking around Amazon, it seems that different types of batteries are measured differently:
Does anyone know why?
Li-ion are measured in mWh
1200mWh ALTIZURE (Cheap-Os)
3200mWh Deleepow
3000mWh AmpTorrent
NiMH are measured in mAh
2000mA... |
H: PT4115, where should I put output capacitor?
The PT4115E datasheet states:
Peak to peak ripple current in the
LED(s) can be reduced below 30% of the average
current, if required, by adding a capacitor across
the LED(s).
Can you confirm that "across the leds" is:
from : between Rs and led
to : between led ... |
H: How to compute clock cycle time from given frequency
let's say I have a processor runs at 100MHZ frequency how can I compute from this it's clock time for each cycle?
I know that Frequency = 1 / Clock Time but I am having trouble to fully understand how to manually convert it for example, to a nanosecond, given the... |
H: Fortifying PCB traces with solder?
In most power supply designs either it's a bench PSU or LED driver etc, manufacturers use solder to increase current tolerance of the PCB trace:
Is it a valid choice or it's just to save money?
What are the disadvantages of doing this?
How much current can solder tolerate?
Does ... |
H: Voltage and Current Sensor for Alternating Current
I want to measure the voltage and current of a AC powered device using a micro controller like Arduino. I am unable to find it.(I am new to these).
Is there a circuit or sensor which isolates from the AC and able to measure voltage and current with voltage and curr... |
H: BLDC motor design, physical appearance question
Excuse me if this is a dumb question, but I always wondered why are BLDC motors usually quite short in comparison to their diameter? Is it due to some electrical properties that make this design the most effiecient? How would you compare two motors that both take up t... |
H: 2 / 4 quadrant switches - how can current have opposite direction to voltage?
I am learning about 1, 2 and 4 quadrant switches, used in inverters etc. I am however struggling to understand how, in the 2nd and 4th quadrant, the voltage can have an opposite direction to current. Using this picture for example
I dont... |
H: Help understanding SR Flip-Flop
The table in the bottom image is the solution for an exercise based on a NAND SR flip-flop.
"Complete the truth table for the SR flip-flop."
The "initially" row is given, and I was supposed to fill in the q and Q-bar values for the remaining rows.
I don't understand the solution - wh... |
H: Op Amp Voltage follower
I built a simple non inverting op amp amplifier with 2 resistors and a TS972IN powered between 0-5V but my output was always set to 5V. I tried several others Op Amp, others resitors and I also moved my circuit elsewhere (I'm working with a breadboard) and none of this changed anything. In o... |
H: Buck Converter Feedback Circuitry
Recently I have been studying feedback in switching power converters, and one thing that is still a bit confusing to me is the way the error amplifier is implemented. Here is what the control diagram looks like from what I understand:
The thing that is still confusing me is the er... |
H: Trying to wire up a couple dozen LED-lit toggle switches to an Arduino Mega
Update: Worked out a rough (I'm sure) schematic of the current idea for a smaller version of the circuit. A bit of info before the question;
The Arduino has a current cap of 200ma across all I/O pins, with a single pin good for 20ma. This i... |
H: Why can both parties feel static electricity
Sorry I'm new to electrical engineering, trying to clear up some confusion on how static electricty works and why both people feel a shock when touched by static electricity.
When creating a circuit, Electrons flow from the source through the load back to the source. H... |
H: Help explain op-amp description by Forrest Mims
The following description is from the book Op-Amp IC Circuits by Forrest Mims (2nd edition 1994):
As a newbie, the entire paragraph is counter-intuitive to me. If amplitude is reduced, why is there a reference to a gain?
Also, if there exists a better textbook on th... |
H: Can I drive 3.75 V / 370 ohm coil relay from Raspberry PI GPIO output?
I have discovered that there are relays like these available on the market that trigger at 3.75 V and have coil resistance above 370 ohm. I assume this would mean about 14 mA or about that might be within allowed limits of Raspberry PI.
How good... |
H: Is ferrite correct material to use for a DC current sensing application
I am trying to build a non-invasive current sensor using a hall effect sensor and ferrite core.
I am using a hall effect sensor sandwiched between 2 halves of a ferrite core like this: ferrite core - digi-key
I grooved out the core with a drem... |
H: Analog reading in raspberry pi
I am trying to read an analog input using a raspberry pi zero W, but all of the GPIO are digital. Can you guys maybe suggest on how to get around this or maybe point me to forums or guide regarding the matter? I am also a beginner in using raspberry pi. all response would be appreciat... |
H: How does an SR Latch get started
Noob question, but I'm not seeing how an SR latch such as the one in the image can "get started". If each input depends on the output from the other, how can there be two inputs to each gate to set the thing in motion?
In a rudimentary circuit consisting of exactly one NOR-based SR ... |
H: Sziklai pair feedback loop
I've read that Sziklai is prone to high frequency oscillations due to its feedback loop.
I can't figure out where this feedback loop actually is.
It should be obvious but I haven't understood this concept.
AI: I have illustrated much of what was said in the answers and comments above and ... |
H: What does the dashed line between diodes in a CMOS protection network mean?
On the datasheet for CD4007 there are schematics for the input protection network:
and the output protection network:
On both, there are 2 diodes connected by a dashed line (D2 on the input and D1 on the output).
What does the dash... |
H: Sziklai pair and Darlington pair input impedence
If i remember correctly the input impedence of a BJT is r_pi=Vt/Ibq.
I've read that using those two configurations I get a much higher input impedence. Can someone please tell me why? Maybe some formulas to prove the fact would be appreciated.
Cheers
AI: Simply follo... |
H: How current leads by 90° in capacitor while charge on other plate is always opposite, should we not say it lead by 180°
When we start charging the capacitors the charge on the other plate is always opposite & equal then how come we say current lead voltage by 90°, should not we say that it lag/lead by 180°.
AI: Act... |
H: Is it possible to reduce the Miller's plateau voltage?
Consider the following circuit:
Image source: Simplified Clamped Inductive Switching Model - Figure 3 from "Fundamentals of MOSFET and IGBT Gate Drive Circuits by Texas Instruments"
I would like to improve the turn on speed of a MOSFET/IGBT. To do this, I thin... |
H: Substituting an inductor - cannot find any pieces containing inductance needed
I am a beginner electronics hobbyist trying to follow an old schematic / instructions to build a theremin.
I have all of the pieces except one. This piece (Toko 154ANS-T1019Z) calls for a "68 µH, hi-Q, variable inductor". However I canno... |
H: Having hard time to identify feedback types
update: I have read similar questions on ee.se, they helped a bit, but it is still hard to understand the type for example in the question in figure. Maybe, you can just explain specially the question below.
Series-shunt, shunt-shunt, current mixing, voltage sampling,...... |
H: Spoofing or hiding monitor serial number
A MAC address of a computer can be spoofed by an FPGA which can be programmed as a network controller. I can set a custom MAC address to it. I turn off the motherboard's network interface controller in BIOS. I use the FPGA that is programmed as a network controller. A softwa... |
H: Is there any reason why 5 volts is so ubiquitous for powering small consumer electronics?
So pretty much every phone charger, tablet charger outputs 5 volts.
5 volts was part of the original USB specification which I assume had some influence on this, resulting in it just being easier to design things to be powered... |
H: What is the correct name for a footprint that connects to a panel mount component?
Let's say you have a panel mount switch. When you create the footprint for this switch, you aren't creating it for the switch itself, rather, you are making a footprint with holes for the wires that will be run to the switch on the p... |
H: Why do I need to use a power amplifier after using a voltage amplifier?
Speaker systems usually use a small-signal voltage amplifier followed by a power amplifier:
Couldn't I use a single voltage amplifier which gives me the desired voltage to drive the load? Why is there the need to have two separate amplifiers?... |
H: Beginner questions on some SMD components in phone motherboard
I'm trying to understand smartphone motherboard components and have a few questions that might be easy for some of you to answer. Please refer to the attached image for the question numbers:
Are these all capacitors?
What is that tiny component that w... |
H: Shifting an audio signal from 0 - 4V to -2 - 2V
I'd like to transmit an audio signal over a digital radio and I figured out I'd need an op-amp in an inverting configuration on the transmitting side to turn a -2V to 2V signal into a 0-4V one. That will be fed into an ADC which then supplies the radio with a digital ... |
H: hall current sensor potential failure mode
I was curious what are potential common failure modes for hall-based ac current sensors in a mains ac environment? Specifically those like the acs712 and acs723. Assume you have a 5amp current sensor, and draw 20+ amps of current through it for a sustained period of time. ... |
H: Synchronous detector question
The author explains it as a synchronous demodulator. Here we can see that two multipliers which multiply both the inverted and non inverted signals.
Can I do the same with only one switch for non inverted signal?
Circuit shown here is from a lock in amplifier milliohm meter.
5 V pulse... |
H: Amplifier memory distortion application
I've found an article about memory distortion issues in audio analog amplifiers. Available for free here.
The author uses in the last configuration a CFP differential input with a cascode of FET controlled by the input and the feedback.
I want to use the same method on the V... |
H: Analyzing RC circuit that has two "switch"
I need to find Vc(t) between 0<=t<=0.01 secs , but teacher draws the second switch as opened. We want to find Vc(t) when t is "less or equal" to 0.01, then why we dont take the switch as closed? Because it is closed at t=0.01 sec.
Is it because of its limit from the left... |
H: Precision Current Sink for LED Modulation
I one of my first designs, I am attempting to simulate a high precision optical transmitter using an LED by varying the brightness in linearly with the incoming signal. The input signal is BFSK, either 30kHz or 50kHz, and ranges from 0V to 5V.
The LED's brightness varies li... |
H: Best practice for handling buffers
I'm writing some evaluation code with a lot of rx/tx operations, using the same two buffers and I started to think about how this could easily go very wrong.
I can argue that it is nice to clear/reinitialize the buffers with 0's or any other val for that matter for safety purpose... |
H: BLDC Motor PWM commutation scheme
Actually I'm trying to understand how to control a BLDC motor using trapezoidal method. I've found two illustrative images that show how to PWM each motor phase:
First
Second
In both of this images, the principle is the same. But in the second image there's also low side driven l... |
H: MCP16301 fail on power up - Vin shorted to Vout
I have designed a step-down converter PCB (4-layer) with MCP16301. It converts voltage from 24V to 5V.
When I connect it to power source and then connect a 100ohm resistor (50mA@5V) it works normally.
But when the load is applied before I power it up MCP16301 dies ins... |
H: Do enclosed switching power supplies follow any standard for their chassis size and mounting hole distances?
Do enclosed switching power supplies follow any standard for their chassis size and mounting holes distances?
or each manufacturer has its own conventions?
AI: Not generally no, they don't have the same size... |
H: Preservation of power when wiring batteries in series - battery life is reduced if load is kept the same
This is really just a "sanity check" type question. Am I correct that if you place two batteries in series, that the battery life is effectively halved relative to just one battery, assuming the load is the same... |
H: Polarization of Radio-Frequency Low-Noise Amplifier
I was reading the chapter about Low Noise Amplifiers from the book "The design of cmos radio-frequency integrated circuits" by Lee, and I have seen this example:
I do not understand the part inside the red circle. It is used to set the correct bias point for M1. ... |
H: Why does having a ground in middle of center tapped transform cause it to split voltage?
At a round 2:52 of this video https://youtu.be/74QrYyYsftY?t=169, the narrator states that connecting a wire through the center of the transformer splits the voltages between two halfs of the transformer. Why exactly does this ... |
H: NMOS - Bulk Voltage going from 0 to -Inf
The question is
Consider an NMOS device where all terminals are at constant voltage except the Bulk terminal. A voltage is applied to the bulk terminal (w.r.t. GND) that varies from from 0V to -Inf. What is the effect on the threshold voltage of the NMOS device?
My understan... |
H: "Fully static" HD63B09EP loses state when clock is paused
The HD6309 is supposed to be a fully static replacement for the MC6809, where "fully static" means that the clock frequency does not have a lower limit. The MC6809 gets the electronics-equivalent of amnesia when the clock is too slow. The HD6309 - supposedly... |
H: How to combine two resistors in a circuit reduction
I'm new to electrical engineering so I've been watching MIT's Open Course Ware videos on Circuits and Electronics. In one of the lectures, the professor discusses the different methods to use in order to reduce a circuit to a simpler form. One of the methods he de... |
H: Due to overcurrent, shouldn't I be extremely cautious when setting an I/O pin as Output?
The question can be applied to any microcontroller with I/O capabilities, but I’m currently working with the popular ATmega328p. Consider the following circuit: A simple SPST Normally Open switch with a 10k pull-up resistor and... |
H: Discrete linear voltage regulator
I am trying to make a discrete component linear power supply. This schematic seemingly works but it doesn't work when I build it on my breadboard.
I am taking 110 volts through a transformer down to 6 volts AC. I added a full bridge rectifier and then a 4700uF capacitor and I get a... |
H: Phase Crossover Frequency at 0 deg or -180 deg
I've learned in school to calculate gain margin by first finding the phase crossover frequency at -180 deg, but sometimes I see people calculate gain margin by finding the phase crossover frequency at 0 deg which doesn't make sense to me. I'm confused as to why that me... |
H: Tool for measuring the frequency of a crystal oscillator
I am building a digital clock from sequential logic. I’m using a 32.768kHz crystal with a CD4060 IC.
I’m looking for a tool to measure the output frequency. I currently have it hooked up to an LED and it’s blinking somewhat irregularly.
Could a rough estimat... |
H: AD620 reference terminal problem
I'm trying to add a DC offset level to a sine signal through an instrumentation amplifier (as the figure below shows.)
The problem is that, in the simulation, everything works perfectly, however, in reality I can't achieve the DC displacement of the signal.
The input signal paramet... |
H: Darlington as CB
Why do we use Darlington pair?
I've heard that we don't use it as common base. Why is that?
Why don't we just develop a BJT with high beta value istead of using this structure?
What are the different types of it?
How can I recognize the emitter and collector of it (for example in the image below)?... |
H: Advice on BNC cables for beginners electronic lab
I'm setting up an electronics lab so I can increase my knowledge of electronics. I've bought some equipment of ebay ('scope, power supply, signal generator etc.,) but don't know what sort of BNC cables I should get.
Do I need to worry about impedance when connecting... |
H: Why use two 0.1 µF capacitors in parallel?
Below is the schematic of the Pololu A4988 driver board:
There are three capacitors on the motor power input. I can understand why engineers decided to use separate 4.7 µF with larger size (1206, 0.1 µF are either 0805 or 0402): because physically small capacitors have lo... |
H: Why does LTspice resistor noise disappear when setting value with .param?
When performing a noise analysis in LTspice of a 1kΩ resistor, a noise level of 4nV/rtHz is simulated.
However, if this resistor value is set to 1kΩ using .param, its noise decreases to 129fV/rtHz. Changing this resistor value does change th... |
H: Why are always used N-Channel MOSFET on both High and Low side on BLDC applications?
As title, I always see an N-Channel MOSFET on both HIGH and LOW side of a 3-phase BLDC motor driver.
i.e.
Can you explain me why is better to use 6 n-channel instead of 3 n-channel and 3 p-channel?
p.s. In this case there isn't hi... |
H: Recommendation on Optical Sensor (being used for Fingerprint Scanning)
When I have researched available optical fingerprint sensor modules, every one comes with a processor that takes the sensor image data and processes it. They all appear to keep the fingerprint data internal to the module, and only allow command... |
H: trying to get motor to turn on
i'm very new to electronics and working thru an udemy course on an introduction to electronics.
I'm trying to get this air pump to activate in a simple DC circuit on a breadboard.
https://www.ebay.com/itm/DC-5V-6V-Micro-2-Position-3-Way-Electric-Control-Solenoid-Valve-For-Gas-Air-Pu... |
H: What happens at hardware level when we feed a code?
I wanted to know what hardware is installed in 8051 such that whenever i write a program it accepts it and execute it.
My query is what happens at the hardware level whenever i feed a program to 8051.
AI: Opcode - the unique identifier for each possible instructio... |
H: Using "modern" batteries with old devices
I have a Sony Vaio p-series laptop which is a tiny computer build in 2009. It is a wonderful device but the battery is only 2500 mah and lasts about 1.5 hours.
My phone battery on the other hand is a quarter of the size, 4500 mah, and lasts almost a day and a half with hea... |
H: LTspice Vs Matlab - Power electroncs
What are the advantages in power electronics of Matlab in comparison with LtSpice and vice versa ?
Thank you very much and have a nice day ! :D
AI: Everyone has their own preferred simulation tool depending on what their background is and what they are simulating most often. Yo... |
H: Can the diode be ignored in this Op amp circuit?
Consider the circuit below:
The diode is ideal and \$R=1000\Omega\$.
What is \$v_o\$ when \$v_{in}=3V\$?
What is \$v_o\$ when \$v_{in}=-3V\$?
So my idea was just to make node equations to solve these to find \$v_o\$, but when I do that I completely ignore the diod... |
H: How to receive the digital data from an ASK/FSK Receiver (E.g. TDA 5210)
While reading the specs on a FSK/ASK Receiver (E.g. TDA 5210 ) I am asking myself how actually the (non Manchester encoded) digital data look like and how to I receive it when sending from another device on the correct frequency
Can the DATA p... |
H: Screen with built-in NFC
So I've started working on a small project (small at the moment) and I'm seeing some issues in my prototype plans, and I need your help with this.
Short answer: I need a led touchscreen with NFC capabilities.
I made a figurine (kind of those you see for games like Skylanders,...). It has a ... |
H: Inductors in DC motor drivers
I've been making some research on DC motor drivers and I noticed that most medium power boards don't use inductors, but boards that can provide high current do, like this one:
https://www.cytron.io/p-60amp-7v-45v-smartdrive-dc-motor-driver-2-channels
What is the inductor used for in m... |
H: How to Convert NPN to PNP transistor?
I'm creating a water level indicator so I can turn on a pump when the water level gets too low. I have NPN transistors, but I would like the transistor to act as a switch that closes when the water level drops below a certain height. The NPN transistor I used for the experiment... |
H: What is a "safe" amount of amps to draw from this pack
I've been working on a quadruped project, and need some help determining the... safety... of my power system.
To start, there's two packs, a larger "main" and a smaller "reserve"
the two packs are built from the same type of battery:
Coolplay 3.7V 500mAh LiPo
t... |
H: Oscilloscope scrolling
This questions is kind of related to this:
Prevent oscilloscope scrolling
However, now I have a decent signal generator (well still budget, but for my needs more than enough, FeelElec FY6900, 60 MHz signal generator).
And two oscilloscope (one I will not mention in this question, but in a nex... |
H: What's the correct sequence to start thinking about a BJT circuit
A very basic circuit as shown below, the 1V step voltage is applied @ +1V @ t=0.
Edit:
Unfortunately the entire question was asked based on a wrong assumption, that is: "Vbe only controls the upper limit of Ic, not the actual amount of Ic, the actu... |
H: 16 bit R2R DAC?
I want to build a 16 bit R2R DAC using two 74HC595 chip. I need the DAC to replace the potentiometer of a lab PSU.
While researching, in the forums and basically everywhere they suggested that R2R DACs shouldn't be above 8-10 bits because they lose precision in higher bits and I have to use 0.001% r... |
H: USB MIDI Host on a microcontroller
I need to interface a USB MIDI keyboard to a microcontroller host.
The microcontroller will be receiving MIDI commands from the USB and occasionally sending MIDI commands.
I'm wondering if there are any implementations on popular microcontrollers like STM32, PIC24 / 32, FTDI etc. ... |
H: How can I use USB output (5V DC) to power a fan 12V DC load?
I would like to power a 5V DC/0.23A fan (beside another device such as 12V LED lamp, and 12V DC water pump). The only possible power source is using USB output, either from computer, mobile phone's charger, and most possible from power bank, which their... |
H: Full wave rectifier with inductor filter
The capacitor-only bridge rectifier can't remove the ripple under heavy load and for a linear lab power supply I need to have an output without any ripple under load. after simulating the bridge rectifier circuit under 1A load I ended up with this;
Ripple without an inductor... |
H: What is the diference between concurrent 2 "when-then", sequential 2 "if-then" and "if-elsif" statements in VHDL?
I want to create an 8 bit counter with reset button on a FPGA board.
I have two signals: btn_up which is debounced and btn_center which isn't. R is an output signal which represents 8 bit counter. I wan... |
H: swapping a louder siren into circuit?
I bought an inexpensive battery-operated door alarm that works using a reed switch and sounds a small buzzer when triggered.
To beef it up, I'd like to swap in a louder separate siren/strobe light to replace the buzzer. The new siren operates at the same voltage, but I'd imagin... |
H: Why is this boost converter application circuit done this way?
The schematic below comes from boost converter AP6714 datasheet - so I assume it's good, but it is very atypical.
Most (all that I used) of the impulse power converters have VOUT connected to the coil. This one has VIN connected to the coil.
Also why i... |
H: A simple way to test op amps
I built this small circuit to test if the op amp is working; or if I understand how they should work.
I don't have a bench power supply so I take the 7 voltage that I have, I used a resistor divider to create 1 volt max; around 900mV and send that into the op amp's inverting input. I gr... |
H: Deriving Coupling Coefficient based on Parallel and Series Inductance (of coupled inductor)
Problem statement
I was wondering whether it's possible to use a coupled inductor (e.g. this) as a signal transformer.
However, these coupled inductors typically have a tradeoff between the ability to store energy in the cor... |
H: Is the voltage at this node 0 volts (quick yes or no)
This is a very quick question, but I'm just in doubt here.
In the circuit below, is the voltage at node A 0 volts? I can see that it is connected to ground, but there is a zener-diode on the way as well. Does that have an impact?
So my question again, is the nod... |
H: Identifying a cylindrical SMD component with two banded color markings
I have been looking at google images of cylindrical smd resistors, but they don't look like the ones on my board.
So my question is: What component is this?
Long story:
This board is a 230VAC to 11.8VAC converter for a lamp which does no longer... |
H: Do I need additional power for an IR LED diode 50 feet away from a Raspberry Pi?
I'm creating a central remote to control my mini-split HVAC units. Those units are controlled with an IR remote. Each unit is in a different room of my house.
I have everything working on my breadboard and the IR LEDs are able to contr... |
H: If I use a 19V 4.7A supply to a MAX 250W ATX power supply am I an idiot or should it be safe enough?
I can do the maths, I get near 90W, but I'm only planning to draw under a quarter of the power supplies (ebay link) rated max of 5V/12V combo (estimated load 30W). I therefore consider my 19V old laptop supply adequ... |
H: 220 volt step-down transformer with 6 secondary wires
I am an electronics novice. :)
I opened a working Casio vintage desk calculator (likely from the late 1980s/early 1990s). It has a 220 volt step-down transformer with six secondary wires. The two mains wires go into the transformer at the bottom. The 6 wires ... |
H: VHDL "can't match slice type array type"
I'm new to VHDL and I'm trying to use code off a teacher's slide that doesn't seem to work as is, and I can't tell what's wrong:
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity Add4 is port (
Data1, Data2 : in std_logic_vector(3 downto 0);
Ci... |
H: How many inrush current limiting thermistor do I need and where should I place them?
In most designs they place a single NTC thermistor in series before the bridge rectifier and in some two or four:
simulate this circuit – Schematic created using CircuitLab
Isn't a single thermistor sufficient for limiting the inr... |
H: How do you make an antenna with length much greater than the wavelength work?
I've read that antennas work best when their length equals 1/2λ, so how does one make an antenna that is 3/2λ, 2λ, 3λ, etc. work? How do I calculate how much energy I am losing compared to the 1/2λ length antenna?
AI: The issue is not tha... |
H: Does layer order matter on multi layer PCB?
I have a 4 layer PCB with the following planes...
Connector (Top): Holds all traces going from connectors to components.
Signal
Ground: Coper filled completely.
Power (Bottom): Coper filled for +15V and traces for -15V
Does it matter if the bottom layer is the power lay... |
H: Why does it take 2 clock cycles to move to the RESET state in my state machine?
I'm writing a finite sequence encoder in Verilog. Basically, an output Z will be activated if the input W is on for at least four clock cycles, or if its off for at least 4 clock cycles. See the following timing diagram
Also, to get so... |
H: Converting Magnetism to electricity
I've been seeing a lot of videos online of people using neodymium magnets to make a motor spin to generate electricity.
If we can generate electricity from magnets why isnt this being used more often?
I'm assuming there are limitations.
E.g heat or the amount of energy the magnet... |
H: Solving a linear system of equations from a mesh analysis in the s-Domain
Here is an exercise from my Textbook in which one is asked to find the mesh currents:
The first thing I did was find the s-Domain equivalent of the circuit:
Now, I can write the mesh equations from it:
From Mesh 1:
$$
\frac{6s\cos{13}+12\... |
H: How can I make my PNP amplifier circuit to turn off faster?
I'm using the following circuit to switch a 24V signal to a PLC. The rising edge is fast and perfect(38 ns) but the falling edge of the signal is not as good(3.5us)!
How can I modify this circuit to have faster-falling edges?
simulate this circuit – Schem... |
H: Infinite loop on microcontroller vs modern CPU
On a microcontroller (more specifically, on an Arduino Uno board using the ATmega 328P microcontroller) I would normally use an infinite loop to check for inputs etc (in Arduino land, this is normally the loop() function). If I leave this function blank however, it doe... |
H: IRF520 as a relay driver
I am trying to use IRF520 as a relay driver for ESP32, but by reason unknown it does not works. I have replaced it twice with a new ones, but yet it keep not working.
I have 3V on the ESP32 pin when the state is HIGH and 0V when the state is LOW.
I am using the circuit below:
Why the IRF5... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.