Searching \ for 'PIC Alarm system' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/microchip/devices.htm?key=pic
Search entire site for: 'PIC Alarm system'.

Truncated match.
PICList Thread
'PIC Alarm system'
1997\11\12@092351 by : Cassie Carstens

flavicon
face
Hi All
My PIC based alarm system have been blown up with a High Voltage
zapper; those handheld units for shocking people/animals...
Aparently this is a new craze among burgulars. Thy kill home alarms,
car alarms and cct video with these zappers.

Short of using screen cable for every sensor, is there other devices
or goodies that can protect alarm systems from this assult????

Regards
Cassie

1997\11\12@093422 by Pasi T Mustalahti

picon face
On Wed, 12 Nov 1997, : Cassie Carstens wrote:
> My PIC based alarm system have been blown up with a High Voltage..
> Short of using screen cable for every sensor, is there other devices
> or goodies that can protect alarm systems from this assult????

PTM: Optics: take half a meter rod of dry air. Make separated
powerfeeds to both ends and hope for the best.
Make the logic work so that light is pulsating when everything is OK.
Hi voltage destroys just about every electronic device. (I been working
with rgt devices just enough)
--------------------------------------------------------------------------
PTM, spam_OUTpasi.mustalahtiTakeThisOuTspamutu.fi, .....ptmustaKILLspamspam@spam@utu.fi, http://www.utu.fi/~ptmusta
Lab.ins. (mikrotuki) ATK-keskus/Mat.Luon.Tdk                    OH1HEK
Lab.engineer (PC support) Computer Center                       OI7234
Mail: Turun Yliopisto / Fysla, Vesilinnantie 5, 20014
Pt 02-3336669, FAX 02-3335632 (Pk 02-2387010, NMT 049-555577)
--------------------------------------------------------------------------

1997\11\12@105045 by Pierce Nichols

flavicon
face
On Wed, 12 Nov 1997, : Cassie Carstens wrote:

> Short of using screen cable for every sensor, is there other devices
> or goodies that can protect alarm systems from this assult????

       Ouch... hrm... you could connect the sensors through
opto-isolators (to protect the core) and then rig up a detection circuit
that sets off the alarm if this happens.

       -p

"I have a work order for the immediate demolition of your reality tunnel."

       -Bob, RAW Construction Corp.

------Begin Geek Code Block------
v3.12
GAT[GCS,GS]d-@s+:!ac++@>$u+>+++>$
P+>+L+>++E+>+W+N++!oK+W--O-M-V--
PS+PE+Y+PGPt+@5+X++R+[GURPS][DARK
SUN]!tvb++>+DI+!DG++e>+++++hr%y++
------End Geek Code Block--------

1997\11\12@112738 by Robert Nansel

flavicon
face
>Hi All
>My PIC based alarm system has been blown up with a High Voltage
>zapper; those handheld units for shocking people/animals...
>Apparently this is a new craze among burgulars. Thy kill home alarms,
>car alarms and cct video with these zappers.
>
>Short of using screen cable for every sensor, is there other devices
>or goodies that can protect alarm systems from this assault????
>
>Regards
>Cassie

Yikes! And I thought I'd heard everything!  What do those zappers put out?
Several kilovolts, I'm sure.

By "screen cable" do you mean shielded cable? I have doubts how effective
plain shielded cable would be against this type of attack.

Hmmm...I'm not sure what could be done about this except to use either
fiber optics for any cable runs or optoisolation on the controller board,
though 5300 KV seems to be tops for cheap optoisolators. If the zappers
produce more than this, you're sunk.

Oh, what else...clamping diodes & current limit resistors on every I/O.
The sensors would all have to be hardened in some way, too.

Defensive software techniques would be helpful, too. Zilog has a really
great appnote on their website: "Using Software Techniques to Maximize Z8
System Software Noise Immunity."

       http://www.zilog.com/frames/z8otp/pdf/z8_app.pdf

It's for their Z8, but the techniques are applicable to most any MCU. These
guys are _really_ paranoid (for example, they suggest scanning your hex
files before programming your MCU to make the WDT reset opcode doesn't
appear anywhere but one place, the place where you call it).

Intel appnote AP-125 "Designing Microcontroller Systems for Electrically
Noisy Environments" is also a good reference Sorry, I don't have an URL for
this one; maybe somebody else out there does...

-BN

----------------------------------------------------------------------------
  Country Robot            "Modular robot components
  69 S. Fremont Ave. # 2     for education and industry"
  Pittsburgh, PA 15202
----------------------------------------------------------------------------

1997\11\12@114854 by Larry G. Nelson Sr.

flavicon
face
You can try using a series resistor to limit current and clamping the
signal with an MOV, Transorb, Diode or other clamping device. This is in
effect protecting from ESD but even more severe. Digital I/O are easier to
protect than analog I/O but the big problem is giving a path for this high
power impulse to go. Perhaps a gas discharge or spark gap would also help
on the lines vulnerable.
Another system that people are playing these types of game with are the
slot machines. These now have to be protected from this type of attack by
design.


At 10:46 AM 11/12/97 GMT+2, you wrote:
{Quote hidden}

Larry G. Nelson Sr.
L.NelsonspamKILLspamieee.org
http://www.ultranet.com/~nr

1997\11\12@121352 by Martin McCormick

flavicon
face
       In the United States, there have been several reports of thugs using
stunners on victims to disable them while a crime was being committed, but
I don't believe I have heard any stories about one-man thunderstorms:-)
yet.  I'm sure it isn't long before somebody tries it here.

       I would think that regular fiber optics could harden a system quite
a bit.  The main problem would be that all the alarm sensors would have to
work with light rather than electricity.  Another more practical possibility
would be to have a PIC do all the sensor monitoring and send a status
message via an optical coupler to a well-hardened PIC circuit that looked
for this status message and turned in an alarm if anything strange happened.
This would mean that the thief would most likely just set the alarm off as
he was trying to zap it.  The PIC that was out on the front line and reading
all the sensors would need to have some kind of validity checker on each
sensor like the resistor used to terminate fire alarm networks so that if
that particular sensor were blinded by a zap, it would do something different
rather than just not respond to the opening of the window or whatever.

Martin McCormick WB5AGZ  Stillwater, OK 36.7N97.4W
OSU Center for Computing and Information Services Data Communications Group

1997\11\12@121401 by lilel

flavicon
face
> >Hi All
> >My PIC based alarm system have been blown up with a High Voltage
> >zapper; those handheld units for shocking people/animals...
> >Aparently this is a new craze among burgulars. Thy kill home alarms,
> >car alarms and cct video with these zappers.
> >


Fight fire with fire.  See the discussion on Tesla generators.  Have
a nice spark gap connected through a circuit that turns on the high
voltage juice, hook that to the frame of your car and ground it
through a little steel chain hanging out the  \bottom......


Best Regards,

Lawrence Lile

1997\11\12@122627 by Martin McCormick

flavicon
face
Robert Nansel writes:
>Yikes! And I thought I'd heard everything!  What do those zappers put out?

       About 50 KV with very little current.  That way one still lives,
probably wishes he were dead.

Martin McCormick

1997\11\12@144855 by Harold Hallikainen

picon face
On Wed, 12 Nov 1997 10:41:44 -0500 Pierce Nichols <.....pn30KILLspamspam.....COLUMBIA.EDU>
writes:
>On Wed, 12 Nov 1997, : Cassie Carstens wrote:
>
>> Short of using screen cable for every sensor, is there other devices
>> or goodies that can protect alarm systems from this assult????
>
>        Ouch... hrm... you could connect the sensors through
>opto-isolators (to protect the core) and then rig up a detection
>circuit
>that sets off the alarm if this happens.
>

       How about putting a pull-up resistor on the sensor, then running
the "pulled-up" sensor through a relatively high value resistor to the
PIC input.  The high value resistor should limit the current through the
PIC input clamp diodes while normal voltages can still pull the high
impedance input up or down.
       I've done this on status monitoring equipment at TV and radio
stations (similar resistor network driving HC devices) and have not yet
lost any parts with lotsa lightning around.


Harold

1997\11\12@150542 by Eric van Es

flavicon
face
Robert Nansel wrote:

> >Hi All
> >My PIC based alarm system has been blown up with a High Voltage
> >zapper; those handheld units for shocking people/animals...
> >Apparently this is a new craze among burgulars. Thy kill home alarms,
> >car alarms and cct video with these zappers.
> >
> >Short of using screen cable for every sensor, is there other devices
> >or goodies that can protect alarm systems from this assault????
> >
> >Regards
> >Cassie
>
> Yikes! And I thought I'd heard everything!  What do those zappers put out?
> Several kilovolts, I'm sure.
>

Can't be too high - it would kill humans if things get that wild. Besides they
run off 'D' cell batts (usually). Although around here the burglars will
probably borrow their taxi's battery to do the job.... :(.

> By "screen cable" do you mean shielded cable? I have doubts how effective
> plain shielded cable would be against this type of attack.
>

Don't think so either - if the HV is running down the one of the cores connected
to the sensor.... Unless its merely to protect against the discharge of these
zappers. That could be considered extremely large noise.

> Hmmm...I'm not sure what could be done about this except to use either
> fiber optics for any cable runs or optoisolation on the controller board,
> though 5300 KV seems to be tops for cheap optoisolators. If the zappers
> produce more than this, you're sunk.

See above. These things will (my reasoning) not produce more than 15kV. Few
milliamps too.They are commonly used to remove drunks from private property and
to break into houses... aagh! i get it... <G>

Else we can wait for MChip to patent and develope a "Brown-UP" circuit... <G>

--
Eric van Es               | Cape Town, South Africa
EraseMEvanesspam_OUTspamTakeThisOuTilink.nis.za | http://www.nis.za/~vanes
LOOKING FOR TEMPORARY / HOLIDAY ACCOMODATION?
http://www.nis.za/~vanes/accom.htm

1997\11\12@160533 by Sean Breheny

face picon face
At 09:56 PM 11/12/97 +0200, you wrote:
>Robert Nansel wrote:
>
>> >Hi All
>> >My PIC based alarm system has been blown up with a High Voltage
>> >zapper; those handheld units for shocking people/animals...
>> >Apparently this is a new craze among burgulars. Thy kill home alarms,
>> >car alarms and cct video with these zappers.
>> >
>> >Short of using screen cable for every sensor, is there other devices
>> >or goodies that can protect alarm systems from this assault????
>> >
>> >Regards
>> >Cassie


This sounds very strange to me. I don't understand why a car alarm would
have any external sensors, or why the CCD camera on a business alarm system
couldn't be sheilded behind glass or put up too high to get at.

I thought that car alarms sensed vibration of the car. Can't this be done
with a sensor that is well within the body of the car, away from access?

I'm sure that there is something that I am not thinking about, but I can't
think of what it might be.

Sean

Sean Breheny,KA3YXM
Electrical Engineering Student

1997\11\12@234056 by tjaart

flavicon
face
Lawrence Lile wrote:
>
> > >Hi All
> > >My PIC based alarm system have been blown up with a High Voltage
> > >zapper; those handheld units for shocking people/animals...
> > >Aparently this is a new craze among burgulars. Thy kill home alarms,
> > >car alarms and cct video with these zappers.
> > >
>
> Fight fire with fire.  See the discussion on Tesla generators.  Have
> a nice spark gap connected through a circuit that turns on the high
> voltage juice, hook that to the frame of your car and ground it
> through a little steel chain hanging out the  \bottom......

Yeah, zap the bastard! I've wondered about the possibilities of
converting a welding machine into a constant current source.
Run the circuit through all the burglar bars and wait for that
sucker to try and saw it off...

--
Friendly Regards

Tjaart van der Walt
tjaartspamspam_OUTwasp.co.za
_____________________________________________________________
| WASP International http://www.wasp.co.za/~tjaart/index.html |
|       R&D Engineer : GSM peripheral services development    |
|   Vehicle tracking | Telemetry systems | GSM data transfer  |
|    Voice : +27-(0)11-622-8686 | Fax : +27-(0)11-622-8973    |
|              WGS-84 : 26010.52'S 28006.19'E                 |
|_____________________________________________________________|

1997\11\13@041012 by : Cassie Carstens

flavicon
face
Hi All
Thank you for the responses.

It seems that the best insulation/protection is 'wire-less' sensors.
But if your wire-less control panel is conected to a communicator
then you still have a conductor to the controller through your phone
line.

As far a cars a concerned, you do not need a reachable sensor. A lot
off wires are available under your car's engine companrtment and even
more under your dashboard. Any connection that is linked to your
alarm system is open for attack.

Fight fire with fire ? Telsas ? shotguns ? One feels like it.
Unfortunateley our Human Rights Bill protects the criminal more than
its law abiding citizens.

I wonder if they will jail a free running (autonomous) robot if it shoots
a burgular in one's house? Or perhaps sends it to the electric chair.

Kind regards
Cassie

1997\11\13@075559 by Gary Sutcliffe

flavicon
face
At 10:46 AM 11/12/97 GMT+2, you wrote:
>Hi All
>My PIC based alarm system have been blown up with a High Voltage
>zapper; those handheld units for shocking people/animals...
>Aparently this is a new craze among burgulars. Thy kill home alarms,
>car alarms and cct video with these zappers.
>
>Short of using screen cable for every sensor, is there other devices
>or goodies that can protect alarm systems from this assult????

Actually its not all that difficult, just takes some care.  Earlier this
year I designed a PIC based unit for a customer that had to get CE
certification for him to sell the product in Europe.  Besides RF emissions
and susceptibility tests, there is an ESD test. Essentially they take a
high tech cattle probe and zap it.  The CE requirements required that it be
able to take an 8KV zap without affecting operation.

I solved the problem with the following techniques:

1.  Good solid ground plane on the PCB.  A multi layer board with power and
ground planes would have been better, but cost was an important factor so I
had to go with a 2 sided board.  You want a very low impedance ground plane.

2.  Current limiting resistors (~100 ohms) and 5.5V MOVs on every input and
output. Harris makes some nice 1206 SMT chip MOVs.  I don't have the part
number handy, email me if you need it.  I think it was the MLA series.

3. Keep the electronics insulated from the case. Be sure there are no
openings that will allow the zapper to get at components or the PCB.  You
don't want to provide a path through the electronics to earth ground.

Good luck!

- Gary


------------------------------------------------------------------------
Gary Sutcliffe,  W9XT          Unified Microsystems
@spam@ppvvppKILLspamspammixcom.com              PO Box 133 Slinger, WI 53086
http://www.qth.com/w9xt        414-644-9036

1997\11\13@105542 by Scott Stephens

picon face
At 11:24 AM 11/12/97 -0500, you wrote:
>>Hi All
>>My PIC based alarm system has been blown up with a High Voltage
>>zapper; those handheld units for shocking people/animals...
>>Apparently this is a new craze among burgulars. Thy kill home alarms,
>>car alarms and cct video with these zappers.
>>
>>Short of using screen cable for every sensor, is there other devices
>>or goodies that can protect alarm systems from this assault????
>>
>>Regards
>>Cassie
>
>Yikes! And I thought I'd heard everything!  What do those zappers put out?
>Several kilovolts, I'm sure.

50,000 to 500,000 volts. Its important to keep in mind the waveform, and
spectrum. Stun impulses are probably in the KHz bandwidth, making sparc
gaps, resistors and capacitors effective.

After you read the Intel AN-125 and zilog stuff, have a look at Microchips
APP note (I forget #) on SCR latchup. If a transient hits your power supply,
it could cause this type of fault to your PIC and other CMOS chips. It will
take extra harware to deal with.

If somebody realy is mad at you, see a tutorial on EMP bombs on Winn
Schwartau's infowar site (http://www.infowar.com?). You may have to go back to
using vacuum tubes ;)

1997\11\13@134458 by Eric van Es

flavicon
face
Sean Breheny wrote:

> At 09:56 PM 11/12/97 +0200, you wrote:
> This sounds very strange to me. I don't understand why a car alarm would
> have any external sensors, or why the CCD camera on a business alarm system
> couldn't be sheilded behind glass or put up too high to get at.
>
> I thought that car alarms sensed vibration of the car. Can't this be done
> with a sensor that is well within the body of the car, away from access?
>
> I'm sure that there is something that I am not thinking about, but I can't
> think of what it might be.

Sean - car alarm typically have: door, bonnet & boot switches and an ultrasonic
sensor for movement detection.

Sometimes in ZA there are some -very_ sharp nails under the seat too
<MaliciousGrin>

Cheers!
--
Eric van Es               | Cape Town, South Africa
KILLspamvanesKILLspamspamilink.nis.za | http://www.nis.za/~vanes
LOOKING FOR TEMPORARY / HOLIDAY ACCOMODATION?
http://www.nis.za/~vanes/accom.htm

1997\11\13@145547 by Montaigne, Mike

flavicon
face
Just a quick idea for comment on this thread:
Small B&W cameras are small (even hidden in smoke detectors) & cheap.
Why not interface to PC (or pic in commercial version) which would take
picture(s)
and store on local disk and/or download to BBS or web-page by phone
whenever triggered by security system.
Obviously this idea is designed to capture a picture of the perpetuators
and
get it 'off location', before they can 'zap' the system.

{Quote hidden}

1997\11\13@162756 by Mike Ghormley

flavicon
face
Robert Nansel wrote:

>SNIP<

>Intel appnote AP-125 "Designing Microcontroller Systems for Electrically
>Noisy Environments" is also a good reference Sorry, I don't have an URL
>for this one; maybe somebody else out there does...

Yes, it is at:

       http://developer.intel.com/design/auto/mcs96/applnots/210313.HTM

It is worth the read, IMHO.

Best regards,

Michael

1997\11\13@174936 by TONY NIXON 54964

flavicon
picon face
I developed a small device that uses any auto wind camera to take a
snap shot of would be thiefs. Any sensor can trigger the device and
the rate and amount a 'shots' is programmable.

I figured, if it worked for banks and the like, it would work from
home.

It also takes photos of yourself sneaking in after a late night at
the pub.


Tony


Just when I thought I knew it all,
I learned that I didn't.

1997\11\17@071830 by paulb

flavicon
face
TONY NIXON 54964 wrote:

> I developed a small device that uses any auto wind camera to take a
> snap shot of would be thiefs. Any sensor can trigger the device and
> the rate and amount a 'shots' is programmable.

 Was that the one published in one of the local mags?

 Cheers,
       Paul B.

More... (looser matching)
- Last day of these posts
- In 1997 , 1998 only
- Today
- New search...