5 ms·

How are you switching mains power safely? I looked into it, but gave up when I realized I'd have to install a rectifier in the wall which just seemed like a fir

How are you switching mains power safely? I looked into it, but gave up when I realized I'd have to install a rectifier in the wall which just seemed like a fire waiting to happen.

lstodd 7y ago
There are basically two options: - learn how to and design a PCB with relays or FETs or whatever, following all the best practices for it to not catch fire. - buy off-the-shelf rail-mounted relays/contactors, then design a driving circuit that will be all low voltage. Assembling it all on a breadboard won't cut it (as in will blow up sooner or later), that's for sure.
wrycoder 7y ago
I use these blocks from Sparkfun: Solid State Relay - 40A (3-32V DC Input) They have four screw terminals - two for 3VDC to control and two for 24V - 380V AC for the load. They have the CE certification. I bolt them down inside a NEMA enclosure and use standard residential wiring techniques (buy a book or two!) to wire them to standard outlets, where I plug in the load. The controller (Arduino etc.) is typically mounted in a small plastic box outside the NEMA enclosure with a terminal strip to attach sensors and so forth. It's powered by a wall wart. This approach meets code and is perfectly safe. For level of competence needed - you should be capable of doing residential electrical wiring. That's a useful skill to learn.
mopsi 7y ago
You can use smart plugs like Sonoff S20[1] and flash your own firmware. They have the widely used ESP8266 inside. I use ESPurna[2] on them, which has many common integrations built-in (Alexa, MQTT, etc) and is very easy to extend further. [1] https://www.itead.cc/smart-socket.html https://www.itead.cc/smart-socket.html [2] https://github.com/xoseperez/espurna https://github.com/xoseperez/espurna
83 7y ago
I've been looking into this as well since the time/risk/insurance issues of diy are kind of putting me off. The Functional Devices RIB (Relay In a Box) devices for ~$10 look pretty slick, only downside is 12v control signal. I ordered a couple to play with but haven't had time to install them yet.

How are you switching mains power safely? I looked into it, but gave up when I realized I'd have to install a rectifier in the wall which just seemed like a fire waiting to happen.

lstodd 7y ago

There are basically two options: - learn how to and design a PCB with relays or FETs or whatever, following all the best practices for it to not catch fire. - buy off-the-shelf rail-mounted relays/contactors, then design a driving circuit that will be all low voltage. Assembling it all on a breadboard won't cut it (as in will blow up sooner or later), that's for sure.

wrycoder 7y ago

I use these blocks from Sparkfun: Solid State Relay - 40A (3-32V DC Input) They have four screw terminals - two for 3VDC to control and two for 24V - 380V AC for the load. They have the CE certification. I bolt them down inside a NEMA enclosure and use standard residential wiring techniques (buy a book or two!) to wire them to standard outlets, where I plug in the load. The controller (Arduino etc.) is typically mounted in a small plastic box outside the NEMA enclosure with a terminal strip to attach sensors and so forth. It's powered by a wall wart. This approach meets code and is perfectly safe. For level of competence needed - you should be capable of doing residential electrical wiring. That's a useful skill to learn.

mopsi 7y ago

You can use smart plugs like Sonoff S20[1] and flash your own firmware. They have the widely used ESP8266 inside. I use ESPurna[2] on them, which has many common integrations built-in (Alexa, MQTT, etc) and is very easy to extend further. [1] https://www.itead.cc/smart-socket.html https://www.itead.cc/smart-socket.html [2] https://github.com/xoseperez/espurna https://github.com/xoseperez/espurna

83 7y ago

I've been looking into this as well since the time/risk/insurance issues of diy are kind of putting me off. The Functional Devices RIB (Relay In a Box) devices for ~$10 look pretty slick, only downside is 12v control signal. I ordered a couple to play with but haven't had time to install them yet.