Battery less arduino. Run on House voltage

Using Arduino Project Guidance
1

Hey community.

Do you guys mind helping me out with a project. I want to run my arduino off my houses 125 volts. Can you tell me what I need and how to set it up and what products to buy?Also I want to run a appliance off the same power supply. How can this be done?

I was thinking Main power supply> To a voltage regulator to step down the voltage>Arduino>RelayRelay is hooked to that same power supply To appliance>Back to main power supply.

But I was thinking if I hooked up a appliance to the relay and turned on the appliance. Wouldnt my arduino just fry?

Im a noob and id appreciate all the help I could get

2

Well you get a common wall wart. Stepping down is not enough, your mains is AC, you need DC.
An Arduino Uno has a plug for that. That is probably how most people run their Arduinos, as Unos are quite the power hogs and most people will not change batteries every few hours.

But honestly, sorry, but looking at your questions, I would suggest to stay away from mains. You obvious lack VERY basic knowledge to make that halfway save. At least you are not living in a 230V country.

3

The Power Switch Tail may be an answer for you. Your 110V appliance would plug into it and it can be controlled by 5V signal. That is if your appliance draws less than 15 amps.

4

The relay will be powered by the same 5V that feeds your arduino and is already electrically isolated.
However the solenoid found in the relay cannot be directly powered by the Arduino's pins, you'll need a transistor to drive it.

The relay boards/module sold on the internet usually already have that relay, so you only need to feed it the same 3-5V that you're feeding your Arduino plus the data signal

Here's the Sparkfun one

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It is still dangerous for us human however, so please read up on it and do not get electrocuted.
If you're not confortable working with mains voltage or not fully understand it, get something like groundfungus posted above

5

Also I want to run a appliance off the same power supply. How can this be done?

That's kind-of confusing, but yes, you could build a box with an Arduino and power supply inside. That box can plug into the wall and it can have a 120V power-outlet that's controlled by the Arduino.

So for example, you could plug a 120V lamp into that box and control the lamp with the Arduino. I've built some sound activated lighting effects that work that way. My project has a box with an Arduino and power supply inside, except the relays are in a separate box, connected by a cable. I built my own power supply from a transformer, rectifier, voltage regulators, and capacitors. I also build by own solid state relays.

I was thinking Main power supply> To a voltage regulator to step down the voltage>Arduino>RelayRelay is hooked to that same power supply To appliance>Back to main power supply.

But I was thinking if I hooked up a appliance to the relay and turned on the appliance. Wouldnt my arduino just fry?

As long as you wire it correctly, it wont' fry. A relay is an electrically-controlled, electrically-isolated switch. So, there's no electrical connection between the relay contacts (120V) and the relay coil.

Most relay coils require more voltage and/or current than you can get from an Arduino I/O pin so you generally need a transistor or MOSFET driver circuit. But, you can buy a "relay board" that has the driver circuit built-in. Or, you can find solid state relays that can be directly controlled by the Arduino. (I believe the Power Switch Tail is a solid state relay).

I was thinking Main power supply> To a voltage regulator to step down the voltage>Arduino>

You can get a ~12VDC or 5VDC power supply. The Arduino has an on-board 5V regulator.[/b] If you look-up the specs, the "recommend operating voltage" is 7-12VDC. Or, you can bypass the regulator and run it from 5VDC.