Electronics 2000

hello all .please help i have been asked to build a buzz wire (you have to move a ring across a wire maze with out the buzzer going off when it touches the wire) its for a school fete , i need the buzzer to go off for a second or two. it needs to be safe and run on a 12 volt battery ,
the thing is i do not know the type of relay to use . been looking on ebay but cannot find one
ps happy xmas to all

Given your (now deleted) abusive posting I'm not too willing to help - people post here in their spare time, no-one is paid to do so.

If you want the buzzer to sound for a couple of seconds you'll need a timer circuit. You could use a 555 timer in monostable mode, this can control a transistor to drive the buzzer. If the buzzer you want to use needs a high current you could drive a relay from the transistor to switch the buzzer, but it probably isn't necessary. I assume the whole thing will run from batteries? Google 555 timer circuits - there is plenty of info around. Electronics Assistant (available from the 'downloads' menu at the top of the page) can help with the component calculations.