Switching 13amp plug electrically

[Bratters]

For a geek project I'm working on, I'd like to be able to switch a 13-amp appliance on and off (at the mains, i.e. at the plug/socket) - however, I'd like to be able to do it electrically based on a small (3-6v) input.

For example, if the 3v is applied, the appliance switches on, if 3v not applied, the appliance switches off. This would allow me to control a household appliance from a computer or similar.

Basically, as I understand it, this is similar to a relay - however to keep things simple and avoid soldering and too much DIY electrics, I'd like it all built into a 13-amp plug adapter.

Anyone got any ideas?

 

[RF Lighting]

http://www.tlc-direct.co.uk/Products/LMESA1.html


http://www.tlc-direct.co.uk/Products/LMESF4.html

 

[beinerts]

If you want to do it from your PC (via a board plugged in to a port in the back?), some level of electronics is probably required. You would need Opto transistor Isolators or Opto Triac Isolators. Unless of course, you can find something similar to the link posted above that would take low voltage input in this way. Don't atempt the DIY solution unless you know what you're doing though.

 

[beinerts]

Another thought, if you can set the secure FM code yourself on the plug linked above (or find it out), I'm sure you can get an interface board for your PC with a transmitter you can use to switch it. The more I think about DIY switching for mains appliances the less of a good idea I think it is!

 

[Bratters]

The more I think about DIY switching for mains appliances the less of a good idea I think it is!

Agreed, I'm certainly not going to try and "make" anything - I know my limits! The RF link above is certainly interesting, although still not exactly what I'm after. I really need to be able to control the 13A from a simple 3V DC line. If such a thing doesn't exist, I'll have to leave it - I'm not going to risk burning the house down and/or electricuting myself for this!

Thanks again, anyway.

 

[TicklyT]

Puts me in mind of the old (ancient?) telex machines.... When a message was received, it operated a small solenoid (based on a relay coil) that allowed a weight hanging on the on/off toggle switch to drop, operating the switch on it's way down. that started the motor of the machine.

The solenoid was also linked to a clutch on the motor shaft. When the solenoid released, the clutch engaged, lifting the weight back up and turning the toggle switch off as it passed.

Heath Robinson? Who is he?

 

[garyo]

Maplins do a remote control 13 amp socket for around £5 per unit. You should be able to feed your 3v signal somewhere into the socket or remote control electronics to trip the relay.

Gary

 

[beinerts]

I've happened across this:

http://www.siliconchip.com.au/cms/A_107104/article.html

No idea if there's a UK supplier. I guess you're also limited to switching local appliances only, unless you want extension leads across your whole house.

 

[plugwash]

looking at that page it looks like an article on how to build one not a readymade product, unfortunately the bulk of the article is pay to view

 

[Bratters]

Thanks for all the replies. There are several ideas there I'm tempted by.

On the other hand, I'm being pretty careful not to bite off more than I can chew with my limited electrics knowledge - I'll have a think!

Thanks.

 

[Adam_151]

What you need is a Solid state relay, the ELV lights an led inside and that switches the LV, some use transformers instead of optcouplers though.

Not sure how common 240v ones are though, seem widely available in the US for 110V though.

I personally would make my own with a Triac based optocoupler and a power triac, could give you the diagram for it, but things like that are probably best on an etched board etc

How is the computer going to be connected to this?

 

[davelx]

You can do it with one of these:

http://www.letsautomate.com/10014.cfm?

plus one of these:

http://www.letsautomate.com/10258.cfm?

 

[tim west]

Depends on the connection to the PC whether Parallel port(printer port) or using RS232 (com port) serial comms.
Parallel port would be easier for connecting unlike RS232 which being serial data you may have to interface through a microcontroller or the like, if you go the parallel port route then this may help you interface:

http://www.epanorama.net/circuits/parallel_output.html#circuithow

I would strongly suggest some form of optoisolation between the interface and the port.