Xref: utzoo rec.autos:20771 rec.autos.tech:9615 sci.electronics:7216
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!brutus.cs.uiuc.edu!apple!usc!merlin.usc.edu!nunki.usc.edu!cyamamot
From: cyamamot@nunki.usc.edu (Cliff Yamamoto)
Newsgroups: rec.autos,rec.autos.tech,sci.electronics
Subject: Re: Car Alarms
Message-ID: <4602@merlin.usc.edu>
Date: 2 Aug 89 15:37:18 GMT
References: <5501@pt.cs.cmu.edu> <446ab2ec.f87f@gtephx.UUCP> <5835@stiatl.UUCP> <5526@arcturus> <6039@stiatl.UUCP> <945@pedsga.UUCP>
Sender: news@merlin.usc.edu
Reply-To: cyamamot@nunki.usc.edu (Cliff Yamamoto)
Followup-To: rec.autos
Distribution: na
Organization: University of Southern California, Los Angeles, CA
Lines: 42

In article <945@pedsga.UUCP> vatche@pedsga.UUCP (Vatche Daghlian,SPCSYS,7546) writes:
>I am in the process of determining the best alarm system to
>install in my new car.  The names that I have run across 
>are:
>	    1)  Crime Stopper
>	    2)  Ungo Box
>	    3)  Derringer
>
>Has anyone out in NET-land had any experience with any one
>of these units.

I have an Ungo in my car and am very happy with it.  I think someone else
also posted they have an Ungo as well.  The Ungo has it hands down in terms
of motion/shock sensing.  Allow me to elaborate a bit.

They use two mecury "bulbs" mounted perpendicular on the horizontal axis.
These "bulbs" are surronded by coils that are connected to a circuit similar
to that in a metal detector.  When you arm the alarm, the microcontroller
allows 30 seconds for the mecury to settle down to the position of car (i.e.
on a hill, embankment, etc).  Once settled, the microcontroller "nulls" the
detector for the current position of the mecury.  From this point on, any
disturbance to the mecury will cause the detector to go off "null" and
trigger the alarm.

This type of motion/shock sensing has no moving parts (unless you consider
mecury in a glass bulb a 'moving part') and thus never wears out.  Because
detection is done electronically, you can adjust the sensitivity and forget
it.  Sensitivity doesn't change due to worn out parts.  Other alarms either
use a mechanical weight-loaded switch that turns on when jarred or a ball
bearing encased above a circuit board with copper traces for conduction when
jarred.

The Ungo can be had for as little as $145 (non-remote) uninstalled.  I'm not
familiar with Crime Stopper but the Derringers start at $300 installed
(** I was going to get a Derringer until I found out no wiring instructions
    are provided and the warranty is void unless a dealer does it for you )
I preferred to install a car alarm myself and since the Ungo had a better
sensor and came with wiring instructions I purchased it.

If you need more tech info on the Ungo let me know.

Cliff Yamamoto