Good news! The same people who gave us PowerSwitch Tail have produced a kit for a similar device to switch 240vAC devices on/off.
A more extended discussion of controlling household voltages...
Forgive my cross post to one other forum? As a former fire fighter, I have something of a bee in my bonnet about people using household voltages...
$17.95 for the kit. Not bad! (Obviously you could roll your own cheaper, but this is convenient).
Another alternative to the switch tail is to use opto-isolated relays.
The advantage is that you can switch up to 8 devices instead of one. Price is around $25.00
The arduino board is safe from AC electrical current on its side.
The danger would be in hooking the wires into the relays but hey turn off your house power first.
The price is good. Here is one URL. These relays can be connected to a arduino sensor board that is stacked onto the arduino microprocessor but probably could be connected directly to the arduino.
http://arduino-direct.com/sunshop/index.php?l=product_detail&p=156
A 4 relay board is advertised here but I don't know if this can be connected to the arduino microprocessor or not. Price is about $11.00.
I HAVE successfully connected the 8 relay system to the arduino and can operate both 110v and 220v household devices..
s
I would generally look to use a zero-crossing SSR for switching AC mains, especially high power devices such as heaters. However, that PowerSwitch Tail device does have the advantage for inexperienced users that no mains wiring is required.
The switch tail would appear to be the safest approach with many appliances.
For 220V appliances in my home that I consider worth controlling with my arduino uno and the switch tail would be the hotwater heater, and electrical space heaters (baseboards).
In these two cases I would have to install female plugs on the ends of the existing wires and this would be most conveniently done inside or beside the fuse panel so that I could plug in the switch tail. So I still have to "play" with 220v wiring in my house on the switch tail side.
The other two appliances where I would not have any issues with would be the dryer and the kitchen stove since in many cases they both have female plug ends nearby into which I could insert the switch tail.
So in many cases we still have to tackle the 220v wiring in the house even if we go the switch tail route. In these cases the opto-isolated relays would not be any less advantageous than the switch tail?
Feedback? is welcome
s
Also worth looking at are Solid State Relays (No sparks (v.bad around gas boilers imo)... much cleaner switching (no bounce) and last a lot longer than mechanical relays). I picked up a Fotek 25Amp SSR for around £5 UK off Ebay and has so far worked perfectly with the heating system. The SSR's are opto-isolated and use triacs for switching so deffo worth looking at as an alternative. Anyone else had experience with SSR's?
Ps. They can also be used as lighting dimmers by setting a rapid pulse on/off (although not tried this with energy saver bulbs)
Cheers,
Ian
I haven't had any experience yet but I've also purchased the same SSR and plan to use it with my heating system. They're meant to be much more reliable than the mechanical relays and safer. Hopefully, it should work fine with my boiler too!
About the SSR's - this chap had a good post on another forum - Tomo (got to admit he appears condescending however he does have some good info in his post on SSR's)
Cheers,
Ian
I used SSRs to interface my living room baseboard heaters to a programmable "furnace" thermostat and it's been working for a couple years now. I pulled them from old copiers and ganged them up, two 120v/20a rated SSRs per leg (4 in total). I have two 8' baseboard heaters so I figured using 4 SSRs would ensure they wouldn't need to work very hard and indeed, they don't even get warm while operating.