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
relay help please
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Re: relay help please
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.
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.