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From: The Natural Philosopher <tnp@invalid.invalid>
Newsgroups: comp.sys.raspberry-pi
Subject: Re: USB controlled mains switch
Date: Sun, 19 Jan 2025 13:07:51 +0000
Organization: A little, after lunch
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On 19/01/2025 09:04, Chris Green wrote:
> Adrian <bulleid@ku.gro.lioff> wrote:
>> I'm looking for a USB controlled mains switch (230V AC) that I can
>> connect to a PI to turn a mains power supply on and off.
>>
>> I've done a bit of digging around on the net, and the options seem to
>> fall into two categories, either a relay device which means having to
>> rewire the device (which I'd rather avoid), priced around 30Euros or one
>> that sits in line (between the device and the supply).  The latter
>> appears to be in excess of 100Euros, which is considerably more than I
>> want to pay.
>>
> I don't understand the difference. Surely anything that's going to
> turn something on/off needs to be "one that sits in line (between the
> device and the supply)" doesn't it?
> 
> Do you mean (the ones that cost 100 Euros or more) something that
> already has a mains plug and socket on it?  I think they're going to
> be expensive simply because they aren't much in demand.  What 'the
> world' wants is a WiFi connected switch and they're two a penny of
> course.
> 
> 
>> Any suggestions on where to look ?  I'm not interested in a wireless
>> solution, as it is likely to be used in places where signals are not
>> reliable.
>>
> I think you'll probably have to bite the bullet and get a relay board
> of some sort. Does it **have** to be USB?  There's lots of quite neat
> relay hats for the Pi.
> 

They aren't especially able to handle 230V at sane currents.

I made my own board up.  Featuring onboard PSU and mains chokes and 
filers and a fuse, a 13A capable relay and a pi PICO. Also has an 
optional temperature sensor hooked up to the ADC

Can send you the Gerbers if interested


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