There was an article in QST years ago about how to use a 555 timer for cor and timeout timer with a hang timer, I actually built one and it worked. I think it would work in your situation.
Maybe some kind soul could find it and post it. tom > [Original Message] > From: w6jll <[EMAIL PROTECTED]> > To: <[email protected]> > Date: 4/21/2008 7:21:37 PM > Subject: [Repeater-Builder] Carrier Control Timer > > With regard to Tom's use of a carrier control timer - I am using GE > EXEC II and MVP's in my system. Although I have relied on the external > controller's time out functions, I would like to have a "backup" timer > in the transmitters that would take the repeater transmitter off the > air at say 10 minutes, if for some reason the contoller circuit failed. > I've looked at the 555 but the problem is that in the monostable mode, > the pulse input to start > the cycle has to be shorter than the timing cycle (according to some > design notes, about 1/3rd or less). Obviously, this won't work for the > intended application since the pulse (key down) would be longer than > the timing cycle. I'm sure someone on the bulletin board has > designed/implemented what I'm looking for. Any thoughts would be > appreciated. TNX Fred W6JLL > > > ------------------------------------ > > > > Yahoo! Groups Links > > > > > > -- > No virus found in this incoming message. > Checked by AVG. > Version: 7.5.524 / Virus Database: 269.23.2/1389 - Release Date: 4/21/2008 8:34 AM
