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.
3,364
questions
-1
votes
1
answer
27
views
Repurpose adjustable standing desk linear actuator for a project on my truck [closed]
Disclaimer: fairly limited experience with electrical engineering.
I'm currently making a deck for my snowmobile that will sit in my truck bed -
a 'Sled deck'. Nice sled decks have telescopic sides so ...
1
vote
1
answer
39
views
Multisim simulation insight
I want to simulate an AC circuit in multisim. I would like hints or articles on how to simulate complex-valued impedance, for example this circuit:
I don't have an option in multisim 12.0 , to have a ...
0
votes
2
answers
65
views
Circuit that outputs signal A when AC sine is positive and signal B when AC sine is negative
I need help designing a circuit that outputs Signal A high when AC sine wave is positive and Signal B high when the sine wave is negative. It's part of a larger project that cycles power in a ...
- 13
0
votes
0
answers
47
views
How to add LED array to 110VAC AC circuit that includes small motor
I'm building a small machine that uses 110 VAC to power a small (14 W) motor. I want to add an LED array that a switch activated by the motor turns on and off. (The motor will also be gearing some ...
- 1
0
votes
1
answer
25
views
Measuring AC current using LEM HAIS 50P
I am working on LEM HAIS 50P current sensor and I'm using it for measuring AC current. I have an offset of 2.5V, so at 0A the output of the sensor is 2.5v which is as expected but if I increase the ...
0
votes
1
answer
45
views
Residual current relay continuity
Even if the leakage current relay is 300 mA, it cannot provide human protection in such a case. Then, if I make a circuit like this, if there is already 270 mA leakage, then if there is an extra 30 mA ...
- 101
0
votes
1
answer
106
views
How can I convert a Noma Ornamotion Christmas tree ornament motor to USB power?
I have a small motor that plugs into the light socket of a incandescent mini light set and spins an ornament. They were called Ornamotion spinning motors.
Now that we're moving to LED, the LED sets ...
- 1
1
vote
1
answer
63
views
How to connect a 12V electromagnet to 220V power adaptor
I'm not very familiar with electronics, but I want to create a basic automatic pet feeder for my outdoor dog house. My idea is simple: a wooden box with a floor that drops at a set time, controlled by ...
0
votes
2
answers
54
views
Can we sell 110V equipment without NRTL certification in a US market?
Only in some places.
Weight scale product
certification
NRTL
110VAC
0
votes
1
answer
57
views
Complex equations in AC RLC circuits spiralling out of control
I'm trying to solve the following circuit. I tried using superposition to find Thevenin at V_o.
First I solved for V_o with the current source and dependant source, then I solved for V_o with the ...
- 31
0
votes
0
answers
59
views
What motor will work best as a generator for low torque input?
I would like to know what kind of motor will work best as a generator.
The input will be RPM with low torque around 20-40 N*mm (this is the minimum.) It should be possible to rotate the motor at this ...
- 1
1
vote
1
answer
74
views
Do Kirlian setups work with DC power? [closed]
I have been trying to build a simple Kirlian setup, and I've been trying to make my flyback transformer work, to no avail, so I shifted to use the small black 3.7 V to 400 kV transformers (as they ...
1
vote
2
answers
67
views
How much clearance do I need for a terminal block that will run at 240VAC, 10A max?
To start off, I don't have any experience with designing PCBs for high voltage relays/switches.
I'm currently designing a PCB that has a relay on it that will be used to turn on and off a device (like ...
- 11
0
votes
0
answers
17
views
ZMPT101B module producing VDC even with AC source disconnected
I am trying to use ZMPT101B to measure 110V AC but even after calibration and using multiple sketches when I power off my AC source it measures some AC voltage (or in other words a signal is still ...
- 123
0
votes
4
answers
139
views
Is touching a neutral wire safe?
Yeah, I know, it is such an old question, so many discussions on this topic, but I cannot realy find an exact answer in the Internet.
I live in Ukraine, where we have 230V AC outlets, as in most ...
- 33
2
votes
1
answer
125
views
Airport runway lighting: What is constant current in relation to alternating and direct current?
I’m an apprentice electrician currently replacing runway lights and pulling new wire at a small international airport.
When I asked I was told they are 5kV direct current. Okay… simple enough. What ...
0
votes
2
answers
55
views
Should Liquid Level Sensors be supplied AC or DC
Liquid level sensors often use two probes, when the resistance between those two probes changes with reference to the level of the liquid between them, that change is resistance is read as change in ...
- 183
2
votes
5
answers
169
views
How to sense the presence of AC voltage that could vary from 17 V to 230 V?
I have a requirement to sense the presence of AC voltage, that could vary from 17 V to 230 V, and trigger a TLPxxx series optocoupler.
The wide voltage range poses a problem in the choice of a ...
6
votes
1
answer
2k
views
Which wire is hot?
I have an analogue oscilloscope that had its power cable head chewed off by something. Before I replace the cable, I want to be 100% sure which side of the cable is hot and which is neutral. This is ...
- 81
0
votes
1
answer
24
views
Current rating of relay with daisy chained parallel power supply
I am using relays to turn on and off appliances that may work on mains or DC voltage. My question is in regards to mains voltage. I am hooking up the live wire to the com pin and the live of the ...
- 1
0
votes
2
answers
75
views
Is measuring 220v AC current from wall socket with multimeter safe?
I've purchased a cheap Aneng multimeter (model SZ08). Since I'm not an expert in electronics, I have some questions related to the usage of this device.
For instance, I wonder if measuring 220v AC ...
- 33
0
votes
3
answers
82
views
Can I join the AC neutral with DC common ground of a circuit with a USB connection?
I am designing an energy meter based on the ATMEL energy meter chip ATM90E32ASAUR with an ESP32.
The problem I have is that, in the application note of ATM90E32ASAUR, they are grounding the AC neutral ...
- 13
1
vote
1
answer
71
views
High voltage DC to AC oscillator circuit [closed]
I am trying to design a oscillator circuit that will convert ~10 kV DC at 60 hz to ~9-10 kV AC at 60 hz, and all the information I'm seeing is circuits that step up voltage. I wonder if making this ...
- 13
2
votes
1
answer
98
views
Switching only one AC side live/netural using Triac/SCR
I was wondering if Triacs/SCRs can be used for switching only one side of AC (neutral or live), or whether there are other component that I can use for this.
The load is an AC motor, and the current ...
- 133
0
votes
1
answer
54
views
Multiple 240v AC LED indicators cross-talk
I have these 230V AC indicator LEDs, which I'm using in a project to indicate when I have various switched circuits live.
Due to space constraints, the switched lives of these LEDs are routed through ...
- 1
0
votes
1
answer
60
views
AC power line filter no load current consumption
Our device is an induction cooktop rated for 2 kW of power. We have added an AC line filter in series with the AC supply line for EMI/EMC performance. Following is the circuit which we have ...
- 29
1
vote
1
answer
39
views
Split AC with diodes - missing current in opposite direction
Here is my circuit
Here is output of measurements:
I cannot understand why there is no current in negative direction. Current keeps flowing in positive direction when there is negative voltage.
- 213
1
vote
1
answer
59
views
3-phase unbalanced power supply [closed]
I have a 3-phase power supply with 115 V phase. I am giving 2 of it phases to AC-DC converter with DC side having 50 W of load. The 3rd phase is no load. There is no neutral connection required for my ...
- 13
1
vote
2
answers
237
views
Connect two mosfets with their sources common
I want to create a "digital AC switch". I came across people using two FETs with their sources common. The AC source is 80V.
The load will draw around 300mA.
Is this circuit, the digital AC ...
- 2,077
1
vote
3
answers
352
views
Can LM358 be replaced with AD8676
I am trying to build an circuit with an PCB to sample the main AC waveform in an ADC set to 0V to 3.3V range. I noticed that there are some ZMPT101B modules that is based on LM358. I made some ...
- 113
1
vote
3
answers
380
views
Would a Variac improve the safety of experiments with old tech?
My little brother likes to salvage/experiment with old tech. Said old tech has to-date included tape recorders (probably nothing to worry about), slide projectors (these seem to blow fuses sometimes), ...
- 111
-2
votes
4
answers
206
views
Do speakers run on AC or DC? [closed]
Do speakers run on AC or DC?
I read online that every speaker runs on AC, but I think that is not quite correct.
- 51
0
votes
0
answers
48
views
Electronically controlled variable AC-AC and DC-AC
I've seen devices (and saw answered questions) that are somewhat similar to what I want to do but I haven't found exactly what I'm looking for. I want to control a power supply with my Raspberry Pi ...
- 1
-1
votes
3
answers
110
views
Why does my voltage regulator always output maximum voltage? [closed]
I bought a cheap AC-AC voltage regulator from AliExpress (marked as being a 4000w SCR) very similar to the one toredown in this article.
As one commenter points out, the output voltage remains at ...
- 515
0
votes
1
answer
75
views
Is this possible? 1phase splitphase auto transformer connected to A 3phase grid
Dear reader,
I have a question about a single-phase auto transformer which is connected to a three-phase electricity grid. The windings of the auto transformer are on a common iron package.
The ...
- 51
0
votes
1
answer
116
views
Need to understand how this circuit works
I am a complete beginner in the field of electrical engineering. Recently, I came across the circuit displayed below and have successfully tested it using both software and hardware simulations. The ...
- 53
0
votes
0
answers
46
views
How can I electronically measure the load of an AC transformer?
I'm wondering how to electronically measure the load of an AC transformer at the output of the secondary winding. I don't want to calculate the core size but use a measurement instrument - which one? ...
- 1,421
0
votes
1
answer
89
views
How to switch a 200 Vpp AC signal @ 2000 Hz in under 1 millisecond?
I want to switch a ~120 V AC signal with a frequency of up to 2000 Hz.
For my application (driving electrolumnescent wire) it is important that the switching duration is not higher than about one ...
- 145
0
votes
0
answers
61
views
AC Power Balance Equation
For the example on Page 7 of this lecture:
https://www.keithmoffat.com/IntrEPS/IntrEPS_Lecture11_PowerFlow.pdf
quoted here:
Are the following balance equations correct?
$$
1=-10 sin \delta_{11}+10|...
- 1
-3
votes
1
answer
91
views
Should I connect a small DC motor directly to the mains without an isolation barrier? [closed]
I recently found out I'd need to pay upwards of $2k in order to supply my entire house with automated blinds. I feel like I can definitely do it myself for a fraction of the cost.
For this purpose I'm ...
- 928
1
vote
2
answers
51
views
Measure power & energy usage in tapped line
Here is the schematic of the circuit in question:
The horizontal lines are from the AC mains. Ammeters and wattmeters are connected at any 2 points in the main lines. I am trying to detect if the ...
- 111
1
vote
1
answer
51
views
What result does digital multimeter show when measuring filtered AC V? Is it Vavg or Vrms of the ripple voltage? What's the formula to calculate? [closed]
Can somebody tell me what result does multimeter show when measuring filtered AC V? Is it V avg or V rms of the voltage ripple? And what's the formulas to calculate this?
- 11
1
vote
3
answers
252
views
Common-Emitter Amplifier
I have the following common emitter amplifier circuit.
I am also told that, when taking the specs above,to consider a 20% safety margin to accommodate for possible parameter variability.
Then there ...
- 167
0
votes
1
answer
54
views
3 phase motor in Steinmetz connection on a single phase supply direction change problem
I want to run a 3 phase induction motor on a single phase power supply.
I'm aware of the low operating power & low starting torque in this configuration.
My load & duty cycles are also not big,...
- 1
0
votes
1
answer
143
views
Can this way verify whether the earth pin is grounded or floating?
I want to check whether the earth pin of the electric AC wall socket is really connected to earth. But I only have access to the socket’s phase, neutral and earth inputs.
I have no access to any known ...
- 1,638
2
votes
2
answers
125
views
Measuring electric generator AC frequency
I need to measure the AC frequency of a 230 V electric generator (gasoline powered).
I have a cheap but ok multimeter that does Hz but the reading is erratic (some 1 kHz...)
The reading on the mains ...
- 123
1
vote
3
answers
93
views
Connecting two power sources to the same load
I'm going to start with a picture to illustrate my question:
The resistor on the far right is my load (which will eventually be an Arduino or a battery which will then be connected to an Arduino) and ...
- 13
1
vote
1
answer
60
views
Biasing AC signal - which circuit is the best?
I've seen a similar question asked earlier here:
How do I bias an AC signal for sampling?
However, I have a 3 different circuits and I am not sure which one works best!
I have: +-2V AC signal of ...
1
vote
1
answer
81
views
Right dimensioning of zero cross detection circuit
I need to detect the zero cross of AC main (220V - 50Hz) with an ESP32 to make a phase shift control of a resistive load.
Searching the web I found this circuit but I have some doubts on how to ...
- 51
2
votes
1
answer
116
views
Repairing Garage Door Control Board
Update summary:
I recapped the whole board :D - It works perfectly!
Re the main/bigger cap, my local electrics shop didn't have a 330uF 35V so I went for a 470uF 35V instead.
Just for my own learning, ...
- 159