FYI, electronics people call this a "retriggerable monostable" or "retriggerable one-shot". Not that that's terribly important. (Because it isn't!) It's just a bit of electronics trivia for anyone who's interested. -Joe Kuchan >From: "ksgrimsr" <knut.s.grimsrud@xxxxxxxxx> >Reply-To: dmcnews@xxxxxxxxxxxxxxx >To: dmcnews@xxxxxxxxxxxxxxx >Subject: [DML] Re: RPM Relay >Date: Mon, 18 Jul 2005 14:57:46 -0000 > >The RPM relay is a pretty simple circuit based on a 555 timer chip. >The basic logic of the circuit is that a received pulse from the tach >causes the 555 timer chip to activate for it's timeout period (a >couple seconds). As long as it receives another tach pulse before its >timeout elapses, the timeout resets and the circuit stays active. The >net effect is that the relay activates on the first received tach >pulse and then deactivates a couple seconds after the last received >pulse. > To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/