Questions tagged [ac]
AC stands for Alternating Current. It usually applies to voltages with >100 V RMS, but can also be used for other AC voltages, like 24 V industrial AC power.
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18 V AC to 5 V DC circuit design with battery
I’ll start by saying I have little understanding of electronic circuits. I have an old door phone to which I have connected a wireless switch in order to be able to open my door with a remote control. ...
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Power Supply is arced and fuses opened
Note: PFC circuit is bypassed
I have my own designed circuit and this circuit is get input of 220VAC/50Hz. Inside of circuit bridge rectifier and filters are exist with this circuit we get 320VDC. So ...
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How does an AC of 5100W (1.5 ton) capacity work without any issue with 1000W of total electricity load of my house? [closed]
I have one AC of 5100W (1.5 ton) capacity and I generally run it along with other appliances like fans, LED bulbs, TV and more. My house is sanctioned ...
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Second opinion on PCB design for relay made in Altium
Edit: I have added the updated PCB design at the bottom over this post (for anyone curious about the progress)
And a big thanks to everyone who commented, it really helped me out a lot!
Original ...
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Understanding Current Ratings in Step-Up Transformers
A step up transformer increases voltage while decreasing current because we can't get more energy than what we had in the first place.
The thing struggles my mind is how his power has a current rating?...
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Can someone help me with a LED light fixture puzzlement? [closed]
I have been buying and using LED bulbs from the Dollar Tree for many years.
I have never had an issue with them in the past. Just the occasional burn out in my home office fixture because it stays on ...
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Power consumption in AC circuit
In a purely resistive circuit, maximum power is consumed. Why? Because, we say, current and voltage are in phase. While in a purely inductive circuit, power consumed in a cycle is zero. Because, ...
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About power factor in circuits
We have an AC circuit with rms voltage V, and resistor R. Assuming that the circuit does noy contain any reactive components, Z=R therefore the rms current flowing in the circuit can be obtained by I =...
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Dealing with High Voltage Low Current Transformer Inrush and bypassing a Thermistor
As a learning project, I am designing a power supply section of a guitar amplifier that uses a 120V Primary, 250V 45mA 40VA Secondary Transformer. Without any thermistor in-line on the main supply, I'...
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How does the "earthing" system works in a UPS
PLEASE SEE EDIT 1
I want to know how exactly the earthing system works in a UPS, an example with by the ECOFlow RIVER 2. From their webpage it seems so simple, you charge the battery, switch the AC, ...
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Should this bare minimum TRIAC circuit light the bulb? [duplicate]
In trying to build a multi-channel, optoisolated, TRIAC based, switch module, I could not even get one channel to function properly.
Trying to isolate the problem, I've reduced the circuit to this ...
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How to reduce notches in input AC voltage for Totempole Power factor Correction circuit?
Respected readers, I am working with a totem pole PFC circuit. In an experimental study, I face a problem of high-frequency notches in source voltage (Yellow one). I found an explanation behind this. ...
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Capacitance for power factor correction formula
I wrote a test the other day and the paper provided a formula for calculating the required capacitance needed for power factor correction. The formula:
\begin{align}
C = \frac{Q_c}{\omega V_{RMS}^2} \...
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Power transformer design calculations
I´m currently designing power transformers in a pretty basic way, using AWG tables for the section of the copper wire, and not knowing what are the real losses, just overdesigning.
Three phase ...
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Is steady state ac circuit analysis possible on a purely inductive circuit?
Is steady state ac circuit analysis possible on a purely inductive circuit? Consider the circuit:
The dynamics should be:
$$
v_1 = L i^\prime + Ri + v_2\\
i(0) = i_0
$$
Now, say we do steady state ...
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How to measure the voltage drop of the power supply when a large load (20 amps) is briefly connected for 20 milliseconds (one cycle of the waveform)
I want to measure the peak voltage of 240V AC supply line accurate to (±5%) within one cycle of the supply waveform, i.e. 20 milliseconds. What should be min. sampling rate and the ADC resolution (12 /...
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LTspice AC/DC converter with DC/DC boost converter
So this is my first time using LTspice and I need to convert my (AC) Vin 11.5V to DC and then boost DC voltage to Vout 22.5V. I have a few givens and some I needed to calculate. I am struggling to ...
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Can I use the mains itself as a ground? [closed]
Basically, an ideal EMC/EMI filter looks like the below circuit diagram.
Ideal EMI filter circuit:
Can I use the mains itself as a ground instead of using a physical ground?
My take on EMI filter ...
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Telecom cables for power transmission
Summary: Can I use abandoned telecom wire bundles as a 3-phase neutral?
Our campus currently has underground AC cables supplying 2 legs of 3 phase wye power to a remote (50 ft away) building. There ...
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Can this circuit be used for an AC-DC emergency LED lamp?
Basically, this circuit is supposed to light the LED lamp from either AC or the battery.
When there is AC available the bulb will glow with the power of AC and the battery will be simultaneously ...
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MDAC AC reference input
I previously had a question on using AC reference voltage with a MDAC, But it has been addressed nicely in the answer below.
How does the "Multiplying Bandwidth" specification relate to a ...
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Are the answers of this questions all incorrect? [closed]
The question is:
What is the voltage of the AC voltage source if Ammeter 1 measure 0.6A and Ammeter 2 measures 0.8A?
R1 is 10 Ohms
R2 is 20 Ohms (See image below)
My solution is :
voltage at R1: (0....
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How to wire a repurposed ac motor
I have an old garage door opener that I would like to repurpose. I would like to bypass the normal garage door logic and add an on-off-on switch. When switched to on1 rotates in direction 1, when ...
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Deriving AC max. average power transfer, where am I wrong?
Starting with the Thevenin equivalent voltage \$V_{th}\$, impedece \$Z_{th}\$ and load impedence \$Z_l\$, the maximum average power transfer seems to be given by \$\frac{|V_{th}|^2}{8R_{th}}\$ but I'm ...
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Does LC circuit convert DC to AC?
I was experimenting with LC circuit (Class 12 - Physics, India) in CircuitJS1 Simmulator.
Interestingly, the LC circuit given below was converting DC into AC.
Circuit:
Circuit Specifications:
DC ...
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How can I make this AC current switch turn on at 20mA instead of 50mA?
I've bought this AC current switch, which is sensitive to currents from 50 mA to 5 A on the single AC wire that passes inside its hole. When currents from 50 mA start to flow in the wire, it allows ...
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Wiring AC 5 Wire Motor with 4 Phases to Run at Max
I'm trying to hardwire a fan motor to always run on max. Currently, it has a circuit board that allows you to adjust the speeds and requires a bit of fiddling to turn on and set the speed when the fan ...
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Graph plot of sinusoidal current/voltage vs displacement of speaker membrane from its resting position
For a very long time I believed that the speaker membrane just moves according to the amplitude of a electrical signal fed to it. Like, If at any instant, the current/voltage is at c% (0 <= c <= ...
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Cost and space effective isolated sensor for low ac currents
I am working on a product where I need to measure small ac current (around 2 mA). The image below shows the wiring:
There is a power supply that powers up a variable power load (this is user ...
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How do ideal inductors dissipate high frequency noise?
I'm confused about the behavior of ideal inductors. As I understand, inductors provide a high impedance towards high frequency signals, which greatly reduces the noise.
How is the reactive energy lost?...
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Transimpedance Amplifier Gain ac and S-parameter Analysis
I'm currently working on finding the transimpedance gain of a transimpedance amplifier. However, I've encountered an issue where I get different gains when performing AC analysis compared to S-...
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Why does phasor multiplication produce a different result with actual sine multiplication?
I thought phasors were shortcuts to the Euler's formula when dealing with sine functions.
For example,
$$\begin{align}\cos(t+a)+\cos(t+b)&=Re\{e^{j(t+a)}+e^{j(t+b)}\}\\
&=Re\{e^{jt}[(\cos a + \...
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How can I prevent backfeed to multiple AC motors connected to the same line?
I have 3-120vac motors that are connected together on one line. These motors move separate vents simultaneously forwards and backwards. Each motor assembly has their own built in limit switch.
My ...
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Inverter, neutral-earth link and RCD breaker
I'm wiring an inverter in a vehicle and I would like to use a RCD breaker to protect against isolation faults.
The inverter is a Mean Well NTS-1200-224EU. The datasheet and the install manual are both ...
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Resistor power rating in an AC circuit
Looking at this question and answer:
Source: Practical Electronics for Inventors, Page 91, Example 5
Shouldn't we use the peak voltage instead of the RMS voltage to calculate the minimum power rating?...
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Measuring the current in a LL circuit with a AC source, doesn't work, i always get this error when i start the simulation, Proteus ISIS
When i click to simulate, it always shows up with this error and it fails
'''[SPICE] singular matrix: check node #L1#branch.
▲[SPICE] singular matrix, check node #L1 #branch.
▲[SPICE] Gmin stepping ...
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Why is the back EMF subtracted from total voltage instead of the voltage across the coil component?
I understand all of this question except for the very end. It is from a test I was looking at from a couple of years ago.
A coil consists of 150 turns of wire and has a total resistance of 200 Ohm. ...
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High current/voltage power monitoring in small form factor
I am attempting to build an I/O board to integrate with software I have running on a Raspberry Pi 4. I need the board to monitor voltage and current (power would be a bonus) on 8 circuits running ...
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How to simplify this AC electrical circuit
My aim is to find out the currents flowing through R1, L1 and C1.
In the original circuit there is one real current source (I1 and R1). I guess the other current source I5 is ideal, because there is ...
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LED light bulb is flickering when switched on
I am a Physics Major student and have to do a project in our end sem.
Since we read a lot of theory and workings and very less practicals, I am a bit weak in electronics.
So here is the problem.
Our ...
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Need to make 380V and 415V 3-phase motors work with 480V 3-phase power supply. Will a 480V->400V autotransformer cut it?
I will have multiple 415V and 380V motors to power with a 480V/3-phase supply due to an international supply chain and tight budget. I would like to know if the solution to my issue is as simple as ...
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AC Phasor Angles in Complex Number Analysis
I'm not sure if this problem is unique to me, but it's been breaking my brain for the past few months. While assuming phasor angles for AC circuit analysis using complex numbers, my teacher said that ...
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Can I modify this AC/AC SSR module to allow it be connected in series with a load at its control pins?
This is a follow-up to my question at: Can I wire an AC/AC SSR input control pins in series with a load?
I have this AC/AC SSR module (Fotek SSR-10AA - schematics and pictures added) and I'd like to ...
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Can I wire an AC/AC SSR input control pins in series with a load?
Is there a way for an AC/AC SSR to trigger when current flows between its input contacts?
I mean, instead of wiring N and L from the outlet directly into its input contacts (with a switch,) I’d like ...
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How can single phase induction motor's direction be reversed?
My house has a ceiling fan which has 2 wires which are connected to a capacitor, and Iam able to control the velocity and direction. After looking about these motors on the web I found out its ...
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Is there any capacitive and inductive reactances in an LC circuit without an AC source?
In a pure LC circuit that is left to oscillate at its natural frequency without any AC source, would there be any \$X_L\$ or \$X_C\$? I don't think there is any reactance in such a circuit, because ...
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Why DC supply voltage is increasing when inverter is connected to powerful three phase induction motor?
If I connect my inverter to a resistive load or small inductive load the DC supply voltage (in my application it is 56 V) stays constant. However, if a powerful induction motor is connected, the DC ...
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Optimizing Incandescent Traffic Light Design
I'm currently working on designing an incandescent traffic light system and could use some guidance on extending and optimizing my design. Initially, I've successfully implemented the required ...
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Determine AC Motor wiring (again)
I have this air extractor which has an AC motor with multiple speeds.
It has 4 wires (Yellow, Black, Blue, White).
I know for sure that the yellow wire is connected to the LIVE on AC 220V
It has a ...
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Convert 0-12V AC signal to 3.3V binary pulses
I want to digitize the signal from an analogue anemometer (windspeed meter), so I can log with a Raspberry Pi etc.
The anemometer outputs an AC signal, where both the frequency and amplitude are a ...
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