#114

Safer Mains (Home Electricity) Detection
How to detect the presence of mains electricity (in your home) using a RasPi or Arduino

So I really want a SAFE way to detect mains in my workshop so can check whether I have left the lights, or more importantly, the heater on.

This method is a NO CONTACT method using just a handful of discrete components and costing a couple of pounds (or dollars), if that much!

It's easy to build on stripboard and runs from 3.3 volts to 5-volts. Actually, you can power this with 9v if you want, it will still work.

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PLEASE NOTE THE CIRCUIT DIAGRAM STATES 2N2904 TRANSISTOR. THIS SHOULD BE 2N3904 TRANSISTOR (or any NPN general purpose equivalent, eg 2N2222).

Everything here is in my GitHub:
https://github.com/RalphBacon/Safer-M...

This is what gave me the inspiration:
How to build your own non-contact voltage detector article (with video) by Kiran Daware
https://www.jameco.com/Jameco/worksho...

1PCS 5A Over current Protection Sensor Module AC Current Detection 12V Relay Module
https://www.aliexpress.com/item/1PCS-...

An assortment of transistors like the ones I use here (2pence or US 3c each!)
https://www.aliexpress.com/item/BC337...
Just watch as you open the lid so they don't all get mixed up (don't ask, no, really, don't)

The sketch I used is simplicity itself but does demonstrate the use of a boolean variable to keep track of the last state.
It's in the GitHub:
https://github.com/RalphBacon/Safer-M...

If you like this video please give it a thumbs up, share it and if you're not already subscribed please consider doing so :)

My channel and blog are here:
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https://ralphbacon.blog
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