Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!apple!gem.mps.ohio-state.edu!tut.cis.ohio-state.edu!husc6!m2c!wpi!reynhout From: reynhout@wpi.wpi.edu (Andrew Reynhout) Newsgroups: sci.electronics Subject: A pathetically simple question... Summary: time-delay circuit schematic request Message-ID: <4377@wpi.wpi.edu> Date: 29 Sep 89 14:47:51 GMT References: <1989Sep28.122217.26867@watcsc.waterloo.edu> Reply-To: reynhout@wpi.wpi.edu (Andrew Reynhout) Distribution: sci.electronics Organization: Worcester Polytechnic Institute, Worcester, MA. USA Lines: 14 Help! This is an amusingly simple question, but I've been working on it for some time now, and can't come up with an answer... I need a circuit that will, on application of power, cause a delay of 5-20 seconds before allowing current to flow through (a different part of the circuit) Basically, it should take, say, 12v, wait 10 seconds, then trip a relay. It's for an alarm circuit. (I didn't see much point in paying $159 for $30 of components and a few hours of work.) I tried a deceptively complex setup with a FET and a timing cap and all sorts of other nasty things, but I can't get ANYTHING out of it. Any help would be greatly appreciated... Andrew