The background is that I have a high tech security siren that I wish to demonstrate to people. The siren is activated (ie it sounds) by pressing a spring loaded button. When one releases the button, the siren stops sounding. The issue is that in order for people to truly appreciate the capability of the siren, they need to experience it for more than 0.5 seconds - which is all they typically hear as they release the button as quickly as possible - due to the horrible nature of the sound. It's a catch 22 situation. So - what I thought of to solve this problem, is a small device - perhaps a cigarette pack sized box which has 2 buttons on it. One would cause the device to sound for 3 seconds, the other for 5 seconds - or thereabouts. That way there would be no option for the user to experience the 0.5 second blip. Has anyone a suggestion as to how to build a 'timed push button switch' like this? Any help would be greatly appreciated! Matthew Auckland, NZ
http://www.kpsec.freeuk.com/555timer.htm#monostable If you're inclined to build kits rather than design your own circuits, these guys aught to be down the street (may save some $ too, they have very reasonable prices): http://www.jaycar.com/productView.asp?ID=KA1732
you could get a refrigeration type time delay for not to expensive on ebay. there should be tons of different variations
Thanks! Hi Thanks to both of you for the helpful suggestions. I'll see if my local Jaycar shop has that Flexitimer kit - seems like just the thing for a complete electronics newbie like me!
