home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: sci.electronics
- Path: sparky!uunet!spool.mu.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!saimiri.primate.wisc.edu!usenet.coe.montana.edu!news.u.washington.edu!uw-beaver!fluke!gtisqr!toddi
- From: toddi@mav.com (Todd Inch)
- Subject: Re: XMAS Lights Theft Alarm
- Message-ID: <1992Dec17.211226.9348@mav.com>
- Organization: Maverick International Inc.
- References: <ByoqLt.DLJ@waterloo.hp.com> <1992Dec08.215021.18099@mav.com> <1992Dec10.182447.16893@vpnet.chi.il.us>
- Date: Thu, 17 Dec 92 21:12:26 GMT
- Lines: 18
-
- In article <1992Dec10.182447.16893@vpnet.chi.il.us> cgordon@vpnet.chi.il.us (gordon hlavenka) writes:
- >>>... The device would work by detecting the AC current being
- >>>consumed by the lights, then triggering an alarm if it drops below a certain
- >>>point.
- > toddi@mav.com (Todd Inch) writes:
- >>This will be very nearly impossible with parallel-wired (C-7 or C-9) bulbs, and
- >>still difficult with series-wired mini lights. Here's why:
- >
- >But you don't need to look at a steady-state current, just a sudden
- >change. This should be pretty simple to spot.
-
- Hmm, didn't think of that. But what if the bulb is disconnected when the
- AC is at/near 0 Volts? I suppose that if the bulb is mechanically disconnected,
- the disconnection would generate some noise that might last long enough for
- the voltage/current to rise again (e.g. essentially switch bounce)?
-
- And of course, twinkle-lights just wouldn't do :-).
-
-