All Questions
172,516
questions
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Hi, In groundwater pump working in star-delta 1st phase gets high & 2nd phase voltage gets low and the 3rd phase is 220, in phase to neutral test
Last time I got good answers for my question here so I came again today. Thanks 🙏🙏
the problem am facing today is in star delta starting motor.
When I connect motor to contactor, in phase to ground ...
- 21
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6
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Voltage controlled 555 bistable operation
below I have a circuit in which I tried to adapt from the 555 bistable configuration to have the 555 states controlled by input A and B; B always goes High before A.
I am trying to have the reset pin ...
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0
answers
4
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LTSPICE Dynamic Power / Voltage Slew Rate Controlled Source
I was just curious if anyone has a dynamic Power or Voltage Slew Rate controlled source, that they could share of point me to.
I need the source to act as the stand in to an external power supply that ...
- 31
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10
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I've designed a new style of ac alternator where both the stator and the rotor rotate oppsite directions so that rpms multiply by each other
My body of information is on a youtube video of nothing more than a hand drawn picture. In explanation of my actions I did this to publish to establish prior art. What I'm curious to know even if its ...
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answers
9
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Motors and torque
In an electrical motor the allowable torque is less than the induced torque due to losses, and we know Tinduced should =Tload to maintain constant velocity. But now Tinduced is reduced and it'll be ...
- 41
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0
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11
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Synthesis of Blocking Statements in Verilog - time required for circuit to complete
This question is purely about synthesized verliog, not simulated.
I have read that blocking assignments are executed in order, but also that blocking assignments assign values to the RHS immediately. ...
- 11
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0
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7
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High power PoE using Cat8 cable's shield
I'm working on a custom gigabit high-power POE solution (ideally 200+ watts). Since Cat8 cable has a lot of shielding, why not use it as a conductor? Using all 4 twisted pairs for DC+ and the shield ...
- 173
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votes
2
answers
41
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Series capacitor not blocking DC voltage
In my understanding a series capacitor (with some resistance) works as a DC block, essentially forming a high-pass filter, blocking DC. Under this assumption, a unipolar square wave of amplitude V ...
- 489
1
vote
2
answers
34
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Using two 2 channel oscilloscope instead of 4 channel
I have a measurement that needs 4 channel scope simultaneously, however, I just have two identical 2 channel oscilloscope. Is there a way that I can still do my measurement accurately?
- 31
0
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0
answers
12
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Transistor Switch Output Current Increasing
I'm using a BJT switch to send a 48 V, 2.5 mA signal (thanks for all the help in the past!). I've been tuning the resistance value I need to output 2.5 mA and noticed that the output current is ...
- 33
1
vote
3
answers
27
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Linear Regulator: What is Current - Supply (max)?
I am using an LDO to step 3.0V from a battery down to 2.8V, and I am trying to figure out what the "Current - Supply (max)" parameter means. Is it how much current can be supplied to the IC ...
- 591
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19
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How do I find the gain function for this circuit?
The cicuit shows a high order low pass filter, where the voltage is 240V RMS. I was told to use laplace to find v0/vi but i am still confused on how to get this and solve for the circuit as asked. I ...
1
vote
0
answers
26
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Simple AVR interrupts in C - How to cleanly stop and restart "INT0"?
I'm trying to use an ATTiny84's INT0 pin to detect a falling edge event on a 1 kHz signal.
What is the correct way to temporarily halt this interrupt INT0, and then resuming it at a later time, ...
- 125
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0
answers
42
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What is this polarized 2-pin connector?
I'm trying to replicate a system using these two-pin connectors and have been having trouble finding them. They look like Molex type connectors to me, but I can't find similar versions. The pins are ...
- 1
1
vote
0
answers
39
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Using reverse conduction on board repair
I am sorry if the title is misleading. As I am not a native speaker, I really don't know what the correct words to be used in the title. If you know the right words, please tell me so I can update the ...
- 121
1
vote
1
answer
24
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An over- and under-voltage protection system
How can the block diagram below operate as an over and under voltage protection system?
I thought it will work as follows:
A step-down transformer is used to bring down the alternating current supply ...
- 11
2
votes
3
answers
47
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DVB reception: Why do I need to add a coaxial cable to my installation to improve SNR of the signal?
I have the following installation:
Dipole antenna <------> Coaxial cable (3 m) <-----> DCB receptor
If I connect my dipole antenna directly to the DVB receptor, removing the coaxial cable (...
0
votes
1
answer
29
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Disconnected wire still lit Tester turns on
I have multiple wires going through an electrical PVC conduit.
Two phase wire carrying 220v AC of 1.5mm gauge.
Two neutral wire carrying of 1.5 mm gauge.
One wire for earthing (grounding) of 1 mm ...
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votes
2
answers
68
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Peak current of inrush limiting inductor?
I have this tricky question and I can't wrap my head around it.
There is this inductor to limit the inrush current that will be charging up a capacitor. I'm questioning the design of it, but I don't ...
- 247
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0
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63
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Is it possible to use a portable power bank to run a 40W amplifier? [closed]
I have a small 40W speaker that I use for home.
I would like to use it outside, and I was wondering if a portable power bank could run it for at least a couple of hours.
If that's the case, how big ...
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votes
0
answers
16
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GPD2846A mp3 module with headphones?
The GDP2846A module has an in-built 2W amplifier which is fine for a small speaker but not for a pair of headphones. I've thought of directly taking the DAC outputs to the headphones and call it a day ...
- 41
0
votes
2
answers
28
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Interfacing PIC18F4550 with Arduino Nano
For a project, I want to communicate with Arduino Nano using PIC: PIC18F4550. PIC is collecting data from MPU6050 and DHT11; I want to send this data to Nano, which is a separate circuit for handling ...
- 101
2
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0
answers
31
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Why did my IGBT die? What did I do wrong?
I was doing some experiments using the following IGBT:
https://www.pollin.de/productdownloads/D130905D.PDF
I used it to drive a load of ~4.7ish Ohm and ~140ish µH from a capacitor bank of 2350µF.
Each ...
- 21
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0
answers
40
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How to check if my outlet's Ground and Neutral is wrongly mixed up or correct? [migrated]
When we moved to a new house I noticed a strangely wired up outlet:
For this outlet, I am really suspicious whether the grounding is messed up and mixed up with the Neutral.
Normally Neutral and the ...
- 37
0
votes
1
answer
47
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Induced voltage in loop around wire in home AC circuit
I have an electric patio heater that has no indication of whether it's on or off. I want to wrap a loop of wire around its power cord, the goal being to induce a current that can power an LED to tell ...
- 103
0
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0
answers
38
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Where to find electron gun? [closed]
The contexte
I am working with an old cathodoluminescence device to do petrographic analysis on ancient marbles. It look like this:
To function it use a electron gun that looks like this:
As you can ...
- 1
1
vote
1
answer
36
views
Combined amps available
If I have 5 AA batteries powering a locking device, what would be the maximum combined available amps available?
I know that 1 AA battery has 50mA but I do not know if I can just combine that value to ...
- 11
1
vote
2
answers
84
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Should I use a DC-DC converter or an LDO?
In my project, I am designing a board which is supplied by a battery. The battery is a LiPo, 3.7 V, 1000 mAh, so its voltage range is 3 - 4.2 V.
All the components on the board need a fixed voltage of ...
- 467
2
votes
1
answer
68
views
Mysterious 1HRA 6-pin chip
I'm trying to fix a dead Chinese vacuum cleaner (Alfawise FJ166) and have identified all components except this small 6-pin chip. It has marking 1HRA and weird ...
- 21
0
votes
2
answers
59
views
Safety of a polarized DC breaker between the battery and the inverter
DC breakers use a magnet to blow the arc into the quenching channel. If the current is flowing in the wrong directly, the arc is pulled into the guts of the breaker and can cause the arc to be ...
- 101
5
votes
4
answers
464
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What are the effects of removing P, I, and D from a PID controller respectively?
A proportional, integral, and derivative (PID) controller can feature three terms.)
We sometimes see only two of the terms in use. For example, the derivative is disregarded for a PI controller. While ...
- 499
-3
votes
0
answers
30
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i can not find a lt1001 operation amplifier in workshop, which closest op-amp to replace it? [closed]
I want replace the lt1001 with another amplifier because I can not find in workshops around me.
4
votes
3
answers
245
views
Can I power my neon sign transformer with a higher frequency?
My NST input says 120 volts 60 hertz. It’s output is 15 Kv 30 mA 60 hertz. I was wondering if I could get a light ballast which I’ve seen drive fly back transformers at 30 kilohertz. Can I get one of ...
- 51
1
vote
1
answer
64
views
Is it possible to connect a Vin to a ref of an instrumentation amplifier?
I have a circuit in which I need an instrumentation amplifier (INA128 (datasheet)) to be connected correctly for it to work. I don't know if it needs another resistance or if the input needs to be ...
- 11
1
vote
1
answer
43
views
Resizing a vector with ARM CMSIS DSP on Teensy 4.0 (Cortex M7)
I have the following code that does the resizing of a 1D vector with nearest neighbor interpolation in a similar fashion you'd also resize an image, only in 1D rather than 2D. Another term would be ...
- 169
0
votes
2
answers
48
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Modifying RC controller to drive with Arduino
Good day all! I am trying to modify an RC car controller to control via an Arduino. The purpose is to send output data from a neural network running on my laptop. It's an autonomous RC car inspired by ...
0
votes
2
answers
71
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If I use a voltage multiplier will the output wattage be less than the input wattage?
A step up transformer steps up voltage and the wattage stays the same from the primary to secondary. Does a Cockcroft Walton generator or Marx generator work this way too? On the full wave Cockcroft ...
- 51
-1
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0
answers
31
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Meaning of Virtual PHY, Managed Ethernet [closed]
Can someone tell me what is the meaning of "Virtual PHY", "Managed Ethernet Switch" & "switch fabric".
Unable to get a good clarity on what terms actually mean in the ...
- 2,182
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votes
0
answers
6
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Which node-ID goes into the COB-ID?
I understand (or so I think) that:
CAN frames have a unique COB-ID made up of a function code plus a node ID
Transmitting nodes will have a (T)PDO mapped to a COB-ID in the OD (1800h - 19FFh)
...
- 1,207
0
votes
1
answer
40
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Modeling a transmission line
I want to simulate a transmission line in PSPICE,
however I ran into a problem.
I got floating nodes error (I looked it up and I was suggested to put a ground on the far side of the transmission line ...
- 123
0
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0
answers
22
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Help with voltage doubler in a WPT application
I need some help with this schematic to have higher voltage at Vrect. This is for charging a receiver at 25 mm in a WPT application. I was expecting a voltage of 2Vin at the output of the voltage ...
0
votes
0
answers
16
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V4L-Utils & Vitis 2021.2 Build Instructions [migrated]
I'm trying to build V4L-Utils using the instruction
System:
Vitis 2021.2,
Ubuntu 20.04.4 LTS
Setup:
...
- 1
0
votes
2
answers
44
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Does the conductivity or resistance change the capacitance value if I use other material for my capacitor plates?
Capacitance depends on surface area. Now I know copper is one of the most conductive materials and is great for capacitors. Steel is so much cheaper though and I can find a plate for the same size ...
- 51
0
votes
1
answer
52
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How to implement a Bookbinder PCB design in Altium
I am planning to design a bookbinder with airgap rigid flex PCB using Altium.
Based on guidelines from Altium, and various other sources, it is important to have "staggered lengths", to ...
- 1
0
votes
0
answers
26
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Drop in Amplifier High Frequency Gain without Large Power Capacitors
I have designed a simple class AB audio amplifier circuit which can be seen below.
I am simulating the amplifier and have used a single, 100uF capacitor for C3 and C4. The simulation is being run ...
- 315
6
votes
1
answer
230
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Analog television: What is the difference between the first IF and second (demodulated) IF?
I am trying to understand what kind of changes occur to a signal in the chips which sit between the tuner and, for example the FM audio demodulator.
Take the attached example - the TDA2546A. It takes ...
- 297
0
votes
2
answers
68
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Variable Forward Voltage Diode
I'm attempting to create a guitar pedal using diodes to clip the audio signal and create distortion. Specifically, I'm trying to create a circuit with variable clipping by using a circuit that acts ...
- 23
1
vote
1
answer
34
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Power Supply Validation - What Matters?
When it comes to validating a power supply (for example, a buck regulator), what parameters matter?
From the research I have done, I think that things such as ripple voltage, percentage overshoot ...
- 591
0
votes
1
answer
34
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What is support for an end-to-end and peer-to-peer transparent clock?
In the datasheet of LAN9353, the description states that it supports "supports end-to-end and peer-to-peer transparent clocks"
Can someone tell me what is the meaning of this?
- 2,182
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0
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40
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Effect of Quality factor of elements on the resonant frequency
I want to see the effect of the series resistor on the resonant frequency that defines the quality factor of the inductor and capacitor.
The resonant frequency is related to inductor and capacitor ...
- 305