Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/17/84; site hplabsb.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!ucbvax!hplabsb!bl
From: bl@hplabsb.UUCP (Bruce T. Lowerre)
Newsgroups: net.cycle
Subject: Re: locks and alarms
Message-ID: <3350@hplabsb.UUCP>
Date: Tue, 18-Mar-86 20:36:52 EST
Article-I.D.: hplabsb.3350
Posted: Tue Mar 18 20:36:52 1986
Date-Received: Fri, 21-Mar-86 03:18:25 EST
References: <3331@hplabsb.UUCP> <643@bentley.UUCP>
Organization: Hewlett Packard Labs, Palo Alto CA
Lines: 33

> In article <3331@hplabsb.UUCP> hplabsb!bl (Bruce T. Lowerre) writes:
> >I've owned four motorcycles starting from my college days.  I had one bike stolen
> >along with my room mate....
> 
> Did you report this to the Bureau of Missing Persons?  :-)

Very good!

I started to write about another alarm device but I'm not sure it made it
to the net.  I'll do it again; apologies if this is a repeat.

Before we invented the center stand alarm, I built an alarm in a metal
box (small chasis box) that contained a MC battery, loud horn, two
relays, and two key switches.  The alarm worked by threading a 15 foot
shielded cable through both tires and pluging in back into the box.  The
alarm itself was an active device in that a current was flowing through
the cable.  If the cable were unpluged or cut then the horn would go off.
The active circut was achieved by one of the relays being locked down by
an alarm set switch (one of the key switches).  If this relay popped up
(normally closed switch), it closed the circut on the second relay, locking
it down and activating the horn.  The second key switch was the on-off
switch.  Both polarities of the active relay circut went through the
shielded cable, the positive through the center conductor and the negative
through the shielding.  This circut had a low amp fuse in series with it.
If an attempt were made to push a pin through the cable (trying to bypass
the length of cable), the fuse would blow and set off the alarm.

This device really worked!!  I never had the alarm go off, probably
because is was very intimidating.  A would be thief wouldn't know what
was in the box.  Could be an alarm, 1,000,000 volts, stick of dynamite,
or neutron bomb.  The problems with it are that it wasn't very portable
and the battery would wear down eventually.  However, it was very good
for keeping one's bike in place overnight.