This tag refers to alternating current mains power. It usually applies to voltages with >100V RMS, but can also be used for ex. 24V industrial AC power.

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Significantly reducing speed of single-phase AC motor

I have a 1/3hp single-phase AC motor spinning my drill press. With the maximum reductions available through pulleys it still runs 10x too fast for one of my applications (i.e., the chuck turns at ...
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3answers
66 views

Vpp for American split-phase 110V AC

I know the 'nominal' voltage of 110/115/120 is both based on Vrms and that stability @ any of those levels is pretty much a fairy tail. I also know that most rectifiers will output ~130-150V after ...
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0answers
53 views

How does an air conditioner cool a room [on hold]

I always notice that when an air condition is working and cooling the room it, is heating outside the room and a Liquid is dropping from the other side of the air conditioner. how does this happen and ...
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2answers
59 views

Why aren't transformers working?

I harvested some transformers from old electronics and decided to take a small 12vac power supply and connect it to the primary winding, all it does is short the power supply and not work, I thought ...
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0answers
31 views

Could I use two 120V ac Heating-Mats directly with 230V mains current?

i want to improve my simple oven. Until now I used several light bulbs (100W, 230v) in ceramic sockets to achieve arroud 95°Celcius, then the circuit is cut until the sensor is measuring 90°Celcius ...
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2answers
161 views

What good is an induction coil in a dimmer switch?

I asked about a dimmer switch, and was told one has an induction coil. What benefit is an induction coil in a dimmer switch? ZE-02S has induction coil built-in on the circuit board, so it is 5/8" ...
2
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1answer
32 views

AC analysis: finding L and R

EDIT: there should be arg[I2] instead of arg[I3] I've tried to replace V1, C1, R1 with Thevenin equivalent, but I've lost in my calculations. Is there any better approach?
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2answers
47 views

Outlet grounding confusion

I don't have much AC knowledge, but I am willing to learn. I've been surfing the web to find out more about outlet grounding. I still want to know more, that is why I am asking this here. Grounding ...
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0answers
55 views

Why isn't my halogen floor lamp working with new bulb and new dimmer switch? [migrated]

I replaced the bulb and the dimmer switch. There is 120V between the connections when switched on. It varies between 115V on low and 122V on high. The bulb has continuity. I also measured the voltage ...
0
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1answer
40 views

Finding L and R in AC circuit

Ammeter readings: A1 = 4A A2 = 2A A3 = 3A Voltmeter reading 24V. Circuit is in AC. I have to find R1,R2 and L. While calculating R1 (R1 = 24V/2A= 12 Ohm) seems to be easy, next steps are not ...
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2answers
45 views

Is an ideal transformer an ideal current source?

I define every circuit element of a primary coil of a transformer that is connected to a voltage source and calculate \$I_1\$ (current of the primary loop). I then connect it to a secondary coil with ...
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2answers
55 views

Power in AC circuits

When I look at the graph of the power in AC circuits versus time (not the average power I am talking about the instantaneous power) it goes from a negative value to positive. On the other hand, I know ...
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3answers
61 views

AC-DC Conversion; How Much Can I Draw?

My question is how much Amperage can I draw in DC using this kind of setup. I have a 3055 and it's rated at 15A. Is that my max draw then? Power systems aren't my thing, so I'm out of my element ...
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2answers
58 views

What is the pole frequency of a three-phase LC filter?

Suppose I have this configuration: Assume L1=L2=L3 and C1=C2=C3. What is the pole frequency of this filter? Edit: As mcmiln says, this is not identical to the question here: Cut Off Frequency in ...
0
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2answers
95 views

Grid is capacitive in the evening

what does this term mean? "the grid in the evening is capacitive"? I work at a company and we are working on integrating a battery storage system on a utility scale for peak shaving of solar. When we ...
0
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1answer
64 views

Splitting AC voltage based on phase

Is it possible to separate the positive and negative portions of an AC voltage wave into two separate lines, where one line has the positive voltage portion (and is neutral when the source is ...
1
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1answer
29 views

Sensitive AC detector circuit

I built a field mill based on this video link. This device generates a sine wave, where I am interested in the amplitude. Once i have the peak, or average value (does not matter, but average would ...
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0answers
38 views

Can DC current be lethal? [duplicate]

can someone get a shock while comes in contact with dc current? if yes then what would be the amount of this DC current to kill someone? how much ac current is needed to kill a human?
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1answer
46 views

wattage consumption of three phase electric motor

i have a 5 hp motor in my factory . at load, it shows 3.5 ampere consumption ( when tested by a meter). is the consumption accurate? someone told me that 5 hp three phase motor will consume 7.5 ...
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1answer
42 views

Motor pump slowed down due to suction blockage

I have a 1 HP, 220V motor pump which was working fine till recently. Last day, some dirt and dried leaves got into the foot valve and blocked the suction pipe. I ran the pump for sometime in that ...
0
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0answers
41 views

Why does multimeter show a voltage of 10 volts in AC mode when I try to measure the output voltage of 5 volt supply? [duplicate]

I was carrying out a small experiment on the working of regulated power supply that consisted of a Transformer, a bridge rectifier followed by filters. I applied 230 volts from the AC mains. Using my ...
3
votes
2answers
53 views

Controlling current of 240V AC

I'm trying to control the current going into my hot glue gun which in turn allows me to control the temperature of it. Saw some online diy projects doing it with a dimmer switch, but I'd like to ...
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2answers
82 views

Currents when converting voltages down

Okay, so I have what could be considered a silly question I should've probably learned when I started working electronics way back when, but I just now thought of it and haven't really needed to ask ...
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0answers
42 views

Transformer Winding with multiple primaries

I'm trying to learn about transformers (Mostly for fun) I've been playing around with this calculator after reading some things on it, and it seems like the lower the resistance of the windings, the ...
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1answer
65 views

Relay Contact Sticking Problem

In the Image... I am trying to put 30A 12V Relay OMRON G8P-1A4P 12VDC parallel to Push Start Button (Dual Starter control for 1HP Pump Motor). But every time relay picks up contact stick... Before ...
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2answers
78 views

Few questions about basic concepts in electronics

So I'm rather new to electronics and I'm struggling to understand some basic concepts because I picked up little information from many different sources so it's starting to get confusing :/ Why does ...
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0answers
42 views

Resistive touch sensor + Darlington pair + shift registers = AC interference?

simulate this circuit – Schematic created using CircuitLab My circuit is based on an Arduino tutorial on daisy-chaining 74hc165's. It's this but with 8 shift registers: ...
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1answer
34 views

Series or Double Input Voltage for Tranformer?

If I'm using 2 identical 120V transformers and I have access to 240V input, is it better to put the two transformers in series to double the voltages on the secondaries, or should I just run a single ...
2
votes
1answer
79 views

How Zero Crossing optoisolator to work with 220VAC?

I want to use a H11AA1 to detect Zero Crossing, but I am not sure how circuit should look like. How much voltage should LED receive inside H11AA1? Here is datasheet: ...
0
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2answers
57 views

switch for AC voltage

I am designing a switch for AC circuit. E.g. when I apply a small DC voltage, AC current is allowed to conduct, otherwise there is huge resitance stop the current from flowing. I found 2 possible ...
1
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1answer
57 views

Can I use any capacitor for a 2 phase AC motor?

So recently I got my hands on an old pump motor, unfortunately the connection diagram is missing. I have already determined this is a 2 phase motor, and that in order to make it work I need a ...
0
votes
1answer
43 views

Soldering ACN/ACL (blue/brown) wires to outlet plug?

I have a 12v 5.0a AC to DC power converter. I want to solder the ACN(blue) and ACL(brown) wires to an outlet plug I cut that has copper wire (black and white). I hope I am on the right path here. ...
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3answers
72 views

Which motor would work best as a generator? [closed]

i've been doing a lot of research into motors to use as a generator in a medium sized wind turbine project. I am lost as to what to do, will a large AC motor with a bridge rectifier be a good ...
0
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2answers
31 views

AC coil sensing circuit with A1120EUA-T Hall effect sensor

I've seen many questions on here asking about hall effect sensors, and their capabilities, and although many seem to say that they can sense an AC magnetic field, I seem to be having a problem. What ...
0
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1answer
47 views

Voltage between AC phase and DC link

Let there be 3-phase rectifier connected to the standard electricity grid with 400V between phases. Measuring voltage between one of the phases (AC) and negative terminal of the rectifier output (DC), ...
1
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1answer
47 views

Power rating for opto-triac trigger circuit resistors

RHS will be using 220v 400watt bulb 2 simple questions 1- does the 360ohm resistors has to be of high watt too ? 2- all i can find is 5-10watt resistors, can i use them ? would they snub correctly ...
0
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3answers
39 views

How to connect IRF 630B N-Channel MOSFET on 220VAC?

Here is datasheet: http://pdf.datasheetcatalog.com/datasheet/fairchild/IRF630B.pdf From my wall is 220 VAC, but from datasheet I think this MOSFET alow just 200VAC (I am not sure please check). ...
0
votes
1answer
71 views

Chinese glue gun small resistance [closed]

So I've bought Chinese glue gun at ebay, but it had incompatible power plug and terrible cable. I decided to replace wire and plug. I disassembled gun, and saw that wire goes straight to tip (which ...
0
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0answers
58 views

Microcontroller (Arduino) issues detecting mains AC power

I've been trying for a while to find a simple yet accurate way to measure power through a mains cable 240VAC I've seen online methods using hall effect sensors. Could someone please help me to ...
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2answers
56 views

Correctly wire dual primary transformer

I have a dual primary transformer out of an old amp and would like to use it for another project. I can't find a datasheet or a way that explains how to wire it for 220 operation. All the diagrams ...
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2answers
95 views

What happens when AC voltage is supplied to DC equipment and vice versa?

I would like to know what would happen if a 240V AC supply is fed to a DC equipment panel or an electronic DC circuit and if a 250V DC supply was fed to an AC motor?
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1answer
44 views

Capacitive Moisture Sensor - Is AC or DC better/more accurate?

I am looking into making a capacitive moisture sensor. This has been discussed many times already, but I am not sure what is the better option, AC or DC. I want to run this off of a battery, so DC ...
0
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2answers
65 views

Location of capacitor in 120V circuit [duplicate]

In a 120V AC motor circuit, a capacitor is wired in series with the start/auxillary winding. I'm a beginner, but I think I have learned that the cap's function is to create a phase shift to enable ...
0
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0answers
26 views

Amount of AC produced in high frequency oscillator/ Slayer Exciter?

Can someone please tell the formula /function for calculating the no. Of oscillations and the amount of AC produced in the circuit This circuit is inspired by Tesla coil
0
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2answers
67 views

What is the general operating principle of an AC Electronic Load?

I'm working my way through electromagnetics and in particular power (line) transformers at the moment. I'd like to be able to run tests of various kinds at different AC loads and possibly at different ...
0
votes
1answer
106 views

How does a capacitor function in a 120v ac motor circuit?

I dont understand the direction of current flow when a capacitor is wired in series with the start windings in, say, a fridge or ac motor running on der 120v ac. Wiring diagrams seem to suggest ...
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2answers
81 views

Smallest 2 Pin AC outlet socket [closed]

For a home automation project I need to source panel mounting electrical outlet sockets which are as low profile as possible and are rated at least 200 watts. Something like a female version of these ...
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2answers
132 views

detecting ac Phase wire

I have a 2 wire ac current and i need to distinguish the phase wire from the neutral one (there is no ground) and pass that information to a microcontroller, and whenever swap between the neutral and ...
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2answers
65 views

What happens if I parallel two somewhat different size transformer primaries?

I have a small toroidal power transformer, perhaps 20VA, about 7cm outside diameter; core cross-sectional area is about \$16 \times 22 mm = 350 mm^2\$. I expect it's a wound silicon steel core. I got ...
0
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1answer
36 views

Why a high voltage AC always present in SMPS AC to DC power adapters

I'hv seen every 2 pin SMPS AC to DC adapters shows a little high voltage respective to the ground on the out put, on both + and GND wires(or more if more wires present). This voltage is high enough ...