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First of I have no experience with electronics so I am not sure what I should be searching for to get this done.

All I have with me at the moment is a arduino and a few connectors and LED's. Is it possible to switch the kettle on/off using just these basics (i.e. I dont want to buy more stuff for now).

The kettle is the most basic kind , i.e. the ones that plug into a wall outlet and have a single switch to turn it on or off. Let me know if you need more info.

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  • \$\begingroup\$ Kinda dangerous for reasons mentioned below. Why do you want to do this anyway? What problem are you trying to solve? \$\endgroup\$ – Marty Jan 12 '11 at 23:30
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There's a particular problem here with the kettle that a relay will not solve. Kettles always have their own switch which trips off when they boil. So even if your relay is on, the kettle will not heat up unless this switch is also on. If you took the kettle apart and shorted out the switch, it would not trip off when the boiling point was reached, so this is very dangerous. If you think you can also replace the boiling point sensor and run the logic through your processor, you should think about the fail safe implications of this and consider your house insurance situation.

Depending on the type of switch used in kettle, it might be possible to fill it and switch it on mechanically, waiting for mains to be switched on by the micro. But you could only boil it once before having to mechanically reset the switch. If that works for you, fine, but bear in mind that kettle are not like lamps that you could just switch on and off whenever you like, and interfering with the switch is hazardous.

Most kettles that I have come across do allow the switch to be on even when there is no mains, but most toasters don't allow the basket to be latched in the down position without incoming mains, so you can see this could be a problem.

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    \$\begingroup\$ I can remember electric kettles that didn't have a switch, they didn't even have a thermostat! \$\endgroup\$ – Leon Heller Jan 12 '11 at 11:28
  • \$\begingroup\$ Whoa thanks for the awesome answer, seems this might be out of my league for a little while unless I can find a way to do this mechanically. \$\endgroup\$ – RC1140 Jan 12 '11 at 13:38
  • \$\begingroup\$ You could also consider replacing the boiling sensor (which is probably just a simple mechanical thing) with a sensor set for a temperature just above that of boiling water. Since you can't heat liquid water above boiling (at pressures you'll encounter in the home), and steam will depart the kettle, once the temperature exceeds that of boiling water you know the water is all gone, and you're just burning the kettle. That would keep you mostly safe in the event the arduino did something dumb. \$\endgroup\$ – Jay Kominek Jan 12 '11 at 17:15
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    \$\begingroup\$ Electric kettles are for wimps. Real kettles sit on a stove top. \$\endgroup\$ – finnw Jan 13 '11 at 0:58
  • \$\begingroup\$ Heh i am sure its going to work out easier controlling my stove \$\endgroup\$ – RC1140 Jan 13 '11 at 7:12
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If you want to control a 110V mains power device, a "power switch tail" is available for markets that use the US-style 110V outlets: powerswitch tail

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No, you don't have enough parts to build a circuit to switch on your kettle.

If it really is a basic kettle with no logic or low-voltage controls, then the switch is controlling your house voltage (110V/230V) directly. The practical limit to an Arduino or any microcontroller is about 5V. Additionally, microcontrollers can only handle DC voltages. If you tried to connect your Arduino to the kettle without any additional components, it would probably explode.

I would recommend that you use a relay to switch on and off your kettle. It is relatively easy to find 110V/230V AC rated relays, with current ratings large enough for safe switching. It is a fairly simple circuit to set up; you need a relay, a driver transistor, and a diode for relay coil.

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The current issue of MAKE (Vol. 25) has an article on controlling a crock pot, which is almost identical to what you'd need to do.

http://makeprojects.com/Project/Yobot-Arduino-Yogurt-Maker/499/1

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  • \$\begingroup\$ Thanks that is great as well but I dont have the parts etc readily available atm. Will keep it in mind though \$\endgroup\$ – RC1140 Jan 12 '11 at 13:41
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Use a mains relay controlled by the Arduino.

You need to take the usual precautions to ensure safety, of course.

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This is a somewhat different approach, and no arduino involved, but you may like the Automatic Button Pusher for inspiration.

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I just used an arduino to drive a servo to 90degrees then back again, and mounted the servo so it would actuate the kettles switch, I also used one of those solar cell battery's for charging your phone so that power is always there handy with an xbee to remotely control it

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