How to activate a relay via the Internet?
 

I need (want?) to be able to activate a 12vdc relay remotely via the internet. I know how to wire the relay at the source, but how do I connect/control the contact via Internet?

Vonage or something like that to ring a bell. Sort of like what the terrorists do using a cell phone to set off a bomb?

Who is the primary target?

Nah. I need to buzz-in the UPS guy at my shop when I'm not around.

Also thinking about hooking up an air horn mounted outside the building. I'd like to be able to blow the horn when viewing my webcams and see someone poking around. That should get their attention...

http://www.oopic.com/oopicr.htm

I have built a couple robots based on one of these little buggers.

Not sure I have the ability to make something work out of that! I know I need a controller of some sort. That would be plugged in to my server which is on 24/7 at the shop. N/O or N/C contacts would be wired to the door buzzer or horn.

What kind of server? Windows? Linux?

Windows. It's not "technically" a server. Just a PC I keep running so I can log-in remotely to do my bookkeeping and check on the webcams. I log-in via a remote access program (sorta like PC Anywhere).

If you want something off the shelf, you need to look at 'home automation' products.

http://www.smarthomeusa.com/Shop/PC-Home/

EDIT: Check this out: http://www.smarthomeusa.com/Shop/PC-Home/X10-PC-Interfaces/

Ah-ha...didn't even think about that. That's what I get for trying to think "outside the box"!

Thanks. SmileWavy

There you go... SmileWavy

You need a PLC (programmable logic controller) set up. Configured for a static IP, connected to a router or to an Ethernet hub/switch off an existing router. Basically you need to set up a private network that has full time Internet connectivity. You also need a power source and logic output modules. The source feeds the input side to the output module. The PLC commands the output module to source the voltage to your relay.

There might be a PC based card that will do the same thing. In that case your CPU would always have to be on with VPN capability from your remote PC.

The entire world beat me to it.SmileWavy

Yes, PC is always running. I remote-in via PC Anywhere.

remote
 

x10 unit's can control anything you want. I think Radio shack carries them. Very simple to install and use. My son controls most of his house that way.