Mains electricity, typically a higher voltage AC waveform used to deliver electrical power to households. In North America 120V, 60Hz, in most European countries 230V, 50Hz. What most people will plug appliances into.

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21 views

Feedback on an AC power measurement design

Here is an AC mains power measurement schematic that I tweaked from one of TI's smartplug designs. This simulates well in LTSpice and I was hoping you could give feedback on this. What improvements ...
3
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1answer
36 views

AC power measurement query

I'm trying to understand and tweak this smartplug reference design from TI. I'm stumped on the Metrology Analog Filters section on page 1. What I do not understand is why is there a 0R resistor on the ...
2
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2answers
128 views

How do I hack my soldering iron?

I bought another soldering iron, very expensive to me. I am very exciting about it. Upon receiving it, My heart is broken. First, I saw the label, 220V; Our AC voltage is 110V. Tried it, doesn't ...
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2answers
82 views

AC/DC optocoupler wiring

Looking for some clarification on the proper wiring of an AC/DC optocoupler (HCPL3700, datasheet) when working with 120vac. From what i read online it looks like a need a resistor on the hot side ...
4
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2answers
670 views

Single LED powered directly from AC mains

Today I disassembled a power strip (power extension) and found a LED connected directly to AC with a normal resistor (not a power resistor). How is it working as I thought it would be burned in no ...
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3answers
22 views

Using thermal overload protection in AC-DC PWM motor driver circut

i'm having some difficulties with calculating the value of the thermal overload fuse in this circuit. The thermal fuse is used to protect the motor and the circuit behind it. The deal problem is that ...
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2answers
59 views

TRIAC Angle of Firing vs Power Delivered to Load, how calculate?

I'm building a phase control system for simple power control to a given load (heater for example). I need an equation to find the relationship between angle of TRIAC firing vs power delivered to load ...
12
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5answers
1k views

Anything special to consider when running a 12v “Bus” throughout my house?

I've recently begun playing a lot with tiny programmable computers/controllers (like the Raspberry Pi and the Arduino), and I'm planning to distribute several throughout my house as various sensors. ...
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2answers
120 views

How safe is my soldering iron? [closed]

I'm have a low cost (<2$) soldering iron, similar to the one shown in the image, except that it has 3 plug terminals. Suddenly something got me thinking about safety, out of curiosity I cut the ...
1
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2answers
30 views

Power Transformer with two Buchholz relays

In my workplace we have a power transformer, on its conservator tank there is a device like a Buchholz relay and its named as Atmo-Seal. What is the purpose of this device?
2
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1answer
83 views

What is a corner-grounded power system?

Another translation, another question. Original German: Antriebssysteme dürfen nicht direkt an TT-, IT- und an TN-S Netzen mit geerdetem Außenleiter betrieben werden! Rough translation: Drive ...
0
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1answer
43 views

Is it possible to make a 150 Hz resonant circuit from RF toroids?

I want to make an LC filter resonant at 150 Hz using a 2.5 uF 400 V CBB61 capacitor and inductor. They are shown in the image below. The toroid core looks like an RF toroid core but I don't know the ...
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1answer
45 views

How do I choose a cable /cord, connected to mains part, that is compliant with IEC 60601-1 3rd ed.?

IEC 60601-1 is a standard for medical devices. It describes which are the requirements for the Means of Operator Protection and Means of Patient Protection, the current leakages and so on. I don't ...
0
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1answer
53 views

Is it possible for lightning strike to travel up ground / earth pin on a mains outlet?

I live in a country that follows the UK mains specification, where there are 3 pins on a wall outlet with the topmost pin being earth/ground. Now, is it possible that during a lightning strike, extra ...
0
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1answer
68 views

How to wire the mains to a transformer for end user safety?

Because this can be deadly, and is best left to someone qualified; advice for hobbyist projects on the web are reluctant to offer advice on safely handling mains connections. The get-around is to ...
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0answers
27 views

Why are Watt-hours used instead of Joules? [duplicate]

Does anyone know why Watt-hours are used instead of Joules in the power industry? Considering that 1Wh=3600J (since 1W=1J/s and there are 3600s in an hour), I don't see why a nonstandard unit would be ...
1
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1answer
590 views

I bought an air conditioner in Thailand rated 220v-240v, 50 Hz. What could happen if I use it in our country which uses 220v, 60 Hz? [closed]

I bought an air conditioner (split type) rated 220v-240v, 50 Hz. What could happen if I use it in our country which uses 220v, 60 Hz? A lead technician from a refrigerator and air conditioner shop ...
7
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1answer
112 views

What is this high power switch symbol?

I am a medical physicist, and I program software for MRI scanners as well as develop electronic devices that interact with them. Because of the way MRI works, it is necessary to use very large power ...
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0answers
45 views

Arduino light switch transformer

I'm building a light switch with an ATMega328 (Arduino) which needs 5v. The light switch will be integrated in the wall where a 220v power line is present. I would like to power the Arduino from ...
1
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0answers
47 views

How were the voltages/frequencies of mains defined? [duplicate]

In other words, are there any historical reasons that set mains supply voltage to 120, 127, 220, 240Vrms per phase, and 50/60Hz? These are the most common voltages/frequencies, there are many others, ...
0
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2answers
69 views

How do I calculate the impedance needed to drop 120V AC?

I've been wanting to use the H11AA1 zero-crossing detector to detect the zero-crossing points of Mains Voltage - 120 V AC @ 50 Hz. The data sheet says that the max forward currents of the diodes are ...
2
votes
1answer
212 views

Triac spurious triggering issue

I have a circuit where I am using triacs to switch home appliances like fan, tube light etc. This is the circuit I am using: (TRIAC1, TRIAC2, TRIAC3 come from arduino GPIO pins) First load is a ...
2
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1answer
78 views

Spurious triggering in TRIAC due to EFT

I am working on a project to control AC load using TRIAC In normal operation it working complete fine But when a fan regulator specifically step type capacitor regulator is used in vicinty the ...
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0answers
76 views

Is it possible a zigzag grounding transformers made from single-phase 220:12 transformers?

We have 20 transformers 220:12V rated 2 A in stock. We want to make an experimental zigzag grounding transformer to reduce the third harmonic current injection from single-phases, slightly unbalanced, ...
0
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0answers
66 views

Causes of power adapter failure

I'm dealing with a circuit which is powered with an external power adapter in 15V DC. The adapter is connected to mains at 220V. Maximum output power is 144W. While testing the circuit the power ...
4
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2answers
138 views

Why do offline switching converters often use discrete rectifiers for bridge?

In conjunction with my independent study of switching converters using textbooks, I am more or less obsessively tearing apart all the low-ish power (say 5 - 25 Watt) switching converters I can find. ...
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2answers
126 views

Cable rating - What is the max amp for a 1.5-1.75mm cable?

I have a new hob (magnetic induction plate). It requires 7200W/32A. The power grid's voltage is 230V (Europe). I have already installed a thick cable and I want to use it (it would be difficult to ...
2
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3answers
63 views

Sensing state of an electrical appliance [closed]

I know nothing about electrical engineering however... Is there a way I can detect when an electrical appliance is on? For example when I turn on my tv, a small blue light turns on so I know, but say ...
2
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3answers
281 views

Where are these 50Hz noises from?

Circuit structure: An AC to DC power converter MeanWell 220V to 5V. The output is 5V. The power grid runs at 50Hz. We build DC-DC converters(Power Module) with multiple orders of Low pass filters ...
0
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1answer
74 views

What is “mains outlet tester” (for proper wiring) in the context of US power connector standard?

I'm curious about this comment. It says what ... in the US or UK you should be able to go to a hardware store and buy an outlet tester for very little money. This is a little plastic housing ...
1
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4answers
130 views

Benchtop circuit breaker

I repair electric appliances and tools. Every once in a while, the main circuit breaker trips when I plug in a device. I don't want to prevent a circuit breaker from doing its job, but I would prefer ...
0
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3answers
128 views

Should I continue with daisy chaining?

I've been daisy chaining power strips and it was no issue until my friend told me it's dangerous. I was using 2 monitors, fan, desktop,55inch TV, monitor speakers, and a phone charger. And he told me ...
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8answers
1k views

Can I use a 10A light switch with an appliance with a 13A fuse?

I have a vacuum cleaner, which I wish to add a switch to, so that I can leave it plugged in all the time and use the switch to turn it on and off. The vacuum cleaner has a fuse rated 13 Amps. I ...
0
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1answer
79 views

SSR not switching dimmed load

I have a system where there is a "master dimmer" (an 800W dimmer designed for household lighting). From that master dimmer, I have a few SSRs switching 40W incandescent light bulbs. The idea being ...
0
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0answers
70 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 ...
0
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2answers
68 views

Calculating AC power figure using the DC current consumption

In a system where I have 220V AC recitified/regulated/converted into 3.3V DC through a transformer and a voltage regulator, would the amount of current I will be drawing from the AC line equal to the ...
0
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2answers
48 views

Hooking up a variable frequency drive

I have a 3-phase blower motor that I am looking to control from a Danfoss VLT 2800 that I purchased on eBay. I am going through the manual and I see this table for the mains connection: . I have in ...
0
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2answers
140 views

Ghost? voltage on lamp outlet when turned off (72V/50V) [closed]

I have a < 10 year old house. And today I wanted to use the 2nd lamp outlet in the living room, and even though it was turned off, I got hit by electricity. I am in 230V, 50Hz country (Measured ...
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2answers
58 views

use of neutral line in power distribution? [closed]

Neutral Line - what is the propose of this line ?. In-case Neutral line failure power will be lose ? In power Distribution We are using Line (phase) for input ~240V, In after usage or cycle, What ...
3
votes
5answers
309 views

Three-way AC switch indicator without adding a wire

I am dealing with some three-way light switches that people are always forgetting to turn off. Any suggestions/schematics for making a simple LED indicator at each switch to indicate if the circuit ...
1
vote
2answers
117 views

Mains Linear Power Supply Protection

This is a two-part question: Why do the so many projects that I see that use basic linear transformer power supplies (i.e., mains->transformer->rectifier->regulator) not have any kind of input ...
0
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3answers
159 views

Recommended capacitor rating for this mains zero-crossing detector

I found this zero-crossing detecting circuit here I want to recreate it, using the parts that I have on hand (or can get cheapest), but I'm not sure how to choose the correct 0.1uF capacitors. ...
0
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2answers
94 views

Power Consumption on 220VAC vs 120VAC

I have an appliance that consumes 5mA when in standby on 220VAC mains. I'm assuming on a 120VAC 60Hz system it would also consume 5mA in standby (can't measure it). Since I haven't measured it, I ...
5
votes
2answers
86 views

High dielectric strength temperature sensor (2500V)

I am trying to measure the temperature on a heatsink that is at Earth ground potential, while my circuit ground is at line potential. Typically I would use something like the Microchip MCP9700 in a ...
3
votes
4answers
500 views

Mains LED light bulb flickers when switched off [closed]

We have LED bulbs in our apartment. In the bathroom, the bulb flickers on and off when it's switched off. Same when it was a CFL bulb before I switched to LED cause I hate CFLs. Our mains voltage is ...
0
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1answer
74 views

Raspberry Pi controlled lamp using a relay & mains procedure

I am trying to turn on and off a lamp I have at home using a relay controlled by my Raspberry Pi. Here are the exact parts I will be using: Raspberry Pi B+ My lamp: My relays: Potential ...
1
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0answers
52 views

Will “dimmable” 120VAC LED bulbs work on half-wave-rectified power? [closed]

My stove's vent hood has a pair of 120VAC 50W MR16s with GU10 bases, e.g. these halogen bulbs. These are some of the last incandescent bulbs in my house, and I'd like to replace them with something ...
3
votes
2answers
85 views

line voltage on live line 220v

I need the input from you electro-wizards. I'm in the Philippines, the power is 220v, 60Hz. In most places there is an absence of a ground line. Lots of people in our area have issues of getting ...
0
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4answers
232 views

Opto-coupler output

I am using this circuit for mains detection: The output fluctuates a little but capacitor and resistor values ensure that Output is logic HIGH when 220V mains is present. Once mains is not ...
0
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3answers
113 views

Splitting mains power into multiple relay-switched circuits

Summary Introduction My goal is to split a 1-gang mains power extension lead into three, have my Raspberry Pi plugged into one of the outputs, and have the Pi able to switch the other two outputs ...