Seeking Schematics

[Jeff Wisnia]

Hi all,

My home is fitted with a 19 year old wired intrusion alarm which has
worked faultlessly since it was installed by a sub to the the general
contractor who built the place. The only service it's required has been
changing the backup gel cell every few years.

I'm a retired EE with many years of experience designing solid state
control systems. I have the technical knowledge and tools to service 20
year old electronics down to the component level. Proper documentation
makes the job easier and avoids my having to "reverse engineer" a device
just to find out what should be going with it's circuitry.

The core Control Panel in our home's system is a Guardaware CU-22

The followng accessories are also used:

Moose Products, Inc. MPI-11 Siren Driver module

Corby Industries Model 86 Latching Relay (Used to bypass an IR motion
detector.)

Guardaware LM-1 (I haven't yet figured out its function, but I suspect
it might be used to blink the green "Loop Closed" LRD's on the keypads
to indicate that the alarm's was tripped, after the "Burglar Bell"
output has timed out.)


We had some unusually severe lightening storms here last week which
knocked out power to the neighborhood. Coincidentaly the CU-22 had the
driver transistor for it's "Burglar Bell" output relay go leaky so the
relay was pulled in anytime the CU-22 was powered by it's ac source,
regardless of the Panel's status. Interestingly enough, if the CU-22 was
running off it's backup battery the "12 volt" bus was lower by enough so
the transistor leakage wouldn't quite pull in that relay.

I was lucky enough to be able to troubleshoot and repair that one easily
enough, but it caused me to think about future service needs. I do have
the Installer's Manual which came with the CU22, but I'd sure like to
get a schematic of the whole pc board to tuck away for the next time I
have to fix it. Schematics of the accessory units would also be nice to
have.

I haven't been successful Googling up anything much about those items,
probably because they're all nearly 20 years old now. I can't even tell
if Guardaware, Inc. is still in business.

Cany anbody help with prints or leads to places where I can get them?

Thanks guys,

Jeff


--

Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can smile when things are going wrong, you've thought of someone
to blame it on."

 

[Jeff Wisnia]

Like most alarm manufacturers, Guardaware never issued panel schematics to
the trade. Jim has a great manual collection but this is one thing you
won't find there. Unfortunately, you're not likely to find it anywhere else
either.

Thanks, and while it's not the first time I've encountered
manufacturer's apparant paranoia over stuff like that, I've always felt
it was pretty short sighted, since if another manufacturer really wanted
to get the design, it'd take at most a couple of days to trace out the
schematic from the circuit board (particularly a single sided board like
the CU-22) and to get what you need, proving it correct with a
breadboard. I've even seen manufacturers sanpaper the labeling off of
integrated circuit chips for the same silly reason.

The world of electronics has of course changed since my CU-22 was
manufactured, and what I just said isn't as applicable to the current
crop of solid state electronics with their integrated processors and
such. Hell, most electronic components are so darned small now that you
practically need a microscope to see them, so tiny that there's no room

The CU-22 was a very simple panel. If it fails again it's hardly worth the
effort to repair it, considering the cost of a replacement panel and keypad
would be in the neighborhood of $100 to $110 (retail).

Well for me it'd be *three* keypads and the little bit of additional
work swapping them in. I did have a look around the web in anticipation
of not being able to fix the panel, and it appears there's not much
current stuff out there that would be a quick swap for the CU-22 and be
happy working with my three existing "dumb" keypads which just give a
momentary contact closure to toggle the panel's arm/disarm and a couple
of LEDs to indicate "loop closed" and "armed". But if I'm wrong about
that, please clue me in.

I totally agree with what you say, for anyone in the business or for
someone whose every spare minute is worth money to them or even those
who would rather play golf or do crossword puzzles than fix broken
stuff. But what applies to folks still in the rat race doesn't
neccessarily apply to those of us who have successfully made it into
retirement.

I'm one of those odd ducks who delights in a doing a successful fix of
something that only needs the right 25 cent part replaced to make it
good as new. And it's determining just which part that is that's the
challenge. I get as much of a kick out of that as I would solving the
whole New York Times crossword puzzle. (As if I ever could.<G>)

Regards,

Jeff

--

Jeff Wisnia (W1BSV + Brass Rat '57 EE)

http://home.comcast.net/~jwisnia18/jeff/

"If you can smile when things are going wrong, you've thought of someone
to blame it on."

 

[Aegis]

Although paranoia is rampant in the trade, I don't think that is the reason
alarm manufacturers don't circulate board level schematics. It's mostly
because there is so little demand for them. Very few tradespeople in the
alarm industry have the skills to do board level repairs. Most installers
wouldn't know which end of a diode is which.

Alarm companies almost never (there are a few exceptions, of course) repair
alarm equipment any more. There are two forces at work behind this. On the
one hand, the equipment is becoming almost entirely microprocessor and SMD
based as you mention. OTOH, over the last ten years or so the industry has
been flooded with non-technical "technicians" who are only trained to
install whatever mini-system their employer is hawking. You can thank the
ADT "authorized dealer" program and similar fast-buck deals for that.

Do you blame ADT for the same thing happening globally across most
(non-alarm) technical industries too? You've got engineers and trained
primates... No room for the tech anymore.

 

[Charles Booth]

Jeff,

You sound like a Bostonian. Retired engineer from Raytheon maybe?

I have a few CU22 panels, used, but functioning. May even have some
keypads for it. Most of my Guardaware installs were CU66's and a few
CU88's. I still have a few hundred CU66's still operating in the
Greater Boston area.

I also have some Corby pads.

Guardaware, a company from Brockton Masachusetts area, was acquired by
International Electronics Inc. (IEI) and the original design engineer,
Chris, may still be there doing his thing. I always thought Chris's
ideas were ahead of their time.

I've saved a lot of "junk," aka antiques, from the 1960's and forward
that will probably end up in the collection owned by Ralph
Sevinor of Wayne Alarm in Lynn Massachusetts.

I still have several customers with CU22's that were installed by
other companies a long time ago.

Reply here if I can be of any assistance.

This thread has reminded me that J. R. requested that I send him
copies of all the Guardaware documents that I have. Was supposed to
do it several months ago. Where does the time go?

Charlie