Burglar alarm system for the house

Hi there..

Currently, i am working on a design project of burglar alarm system. This is required by the subject i took in my course. I am not really good in this 'sensor' field. Since this is a design project, the cost is not a matter.

There are some doubts i faced.

If i use motion detector, magnetic switch sensor, and security screen, would it be sufficient to ensure the security of the house?

Which one is better?A security screen or a glass break detector??

I have come across the motion detector with pet and curtain immunity. How does this thing works? How it can omit the motion of the curtain and the temperature of the pet?

Can anyone supply me more info on the type of the sensor to be used?

I would also like to know the range and the coverage area of the motion detector.

Thanks alot..

cwt said:

If i use motion detector, magnetic switch sensor, and security screen, would it be sufficient to ensure the security of the house?

Click to expand...

It depends on the kind of place you want to secure and the the location. For example if it is a flat in a city it's ok but if it is an industry building on the country it is not enough.

cwt said:

Which one is better?A security screen or a glass break detector??

Click to expand...

In my opinion and my experience I prefer the glass break detector.

cwt said:

I have come across the motion detector with pet and curtain immunity. How does this thing works? How it can omit the motion of the curtain and the temperature of the pet?

Click to expand...

It is ussually a matter of sensitivity.

cwt said:

Can anyone supply me more info on the type of the sensor to be used?

I would also like to know the range and the coverage area of the motion detector.

Click to expand...

Take a look to suppliers companies such as www.Paradox.com etc

If you need anything else or if you tell me the exact place you want to secure I'll be glad to help ypu more!

Thanks for your help.

I am doing an alarm system for a house. Just a normal double storey house will do. The owner of the house might have pets like dogs and cats.

I think using glass break detector, motion sensor and switch sensor will do. Do you agree? I would like to connect all those sensors to a main system, where it'll sounds the alarm when someone break into a certain zone.

I would like it to be simple but with fully secure environment.

I think you are ok. Simple is the best way!
Just be carefull to cover all the areas and pay attension about the pets and ppl walking outside the house (motion sensors -> windows)

What you mean by (motion sensors -> windows)??
You mean the curtain?

I have some doubts about the control panel. Is it we need to connect all the sensors to the control panel, which act as the main 'brain' of the whole system?

Regarding the magnetic switch, is it reed better than surface magnetic switch??

I mean the curtains and ppl moving outside the house. The motion sensors can't be pointed to a window.

Yes the control pannel is the brain of the system.

I think for your use magnetic switch type is ok.

I have something to ask about the control panel. How should i program it?

Is it for every zone, we need to implement some kind of 'logical' circuits and then connect the circuits output to the control panel??
Eg. if the glass break detector and motion detector is triggered, a HIGH will generated by the 'logical' circuit and than trigger the specific zone in the control panel. Is it like that?

Thanks for helping..

you might be able to use some ideas from here

**broken link removed**

It is basically the control panel is made up of sensors logically connected together?

Yes. When you'll decide your supplier, it will be easier for you to understand how the various components work from their specifications and termination instractunions.

Is there any helpful schematic diagram of a typical motion sensor?
A circuit shows how it should be connected to perform a certain application?

Hi cwt,

I am a professional alarm installer with over 30years of experience. Let me first say that what you are doing is how I started in the business. I wanted to build my own alarm system way back when. We didn't have the internet to ask for assistance then.

Let me see if I can remember some of your questions.

Motion sensors: A pet immune motion sensor is a sensor with a microcontroller built into it. The controller has a library of know false alarm causes and every time it "sees" movement, aka temperature change, within its field of view it runs thru the library and makes a determination if it qualifies for an alarm condition. The curtain you refer to is not a curtain in the sense of a covering over windows. The curtain refers to the shape of the viewing pattern of the detector.

Glass break: The are several types of glass breakage sensors available today. Audio type which "listen" for the sounds (specific frequencies and time frames/durations of the sounds) of glass breakage. Another type is one that adhers to the glass with thin double stick tape and uses a piezo crystal flexing to detect the glass breaking. The last type that was always my favorite is the shock sensor that mounts on the frame of the window. Which type to use depends on several factors. If you have curtains or blinds between the glass and the audio type detector then it probably won't work because the window dressings will muffle the glass break sounds. The stick on type is fine but if there are multiple panes of glass then you need a sensor on each pane and then that looks like crap! The shock sensor type is great because it can cover up to 72 sq ft of window and multiple panes. This sensor also requires a separate processor. You can have up to 50 sensors on one processor. They are tricky to work with but like I said earlier they are my favorite.

If I had my choice today I would probably use window screens. They cost more but I like having my windows open and still having security.

There are alot of sensors available today. You have to look at each situation and decide what sensor would be better suited for your application. Every installer has their preferred brand of products. Manufacturer's trining on the proper use and installation is extremely critical to a false alarm free installation. I personnaly never recommend a person doing it themselves only because of the false alarm factor.

Hope all of this helps. you can PM me at secser@ncweb.com if you need any further help.

BOBK

Added after 5 minutes:

Hi cwt,

I just went back to your previous posts. Are doing this for someone else or is it for yourself?

If you are doing it for someone else think first about one word>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> L I A B I L I T Y <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

I think about it all the time. If there is a loss to the homeowner and you installed the alarm system for them and it is proven that the system was ON and it didn't work, guess what? Their insurance company will come after you for their loss.

Just some thoughts!

BobK

Thanks..alot!!

This is a design project for one of my subject. Yes, i am designing a system for commercial purpose. But i need not to be so 'deep' into it because this is only a design project and the time given to complete this task is not much. So the 'surface' information will do for me..

I have some doubts to ask about. I have been thinking the following situation quite some time.

Eg. the owner need to take something at the living room. So when he walk to the area, the motion sensor senses motion and triggers the alarm. By considering this situation, i would like to AND the motion sensor with some other sensors (magnetic switch or shock detector). By doing this, the owner will not be detected even if he roam around the area, since the rest of the sensors remain untriggered. However, if an intruder break in, he shall trigger the motion sensor and either the magnetic switch or the shock sensor. So, both sensor will produce high output and the AND circuit will gives high to trigger the alarm system. Can this concept works?

For now i am keen to know more about motion sensor. I would like use 'indoor' and 'outdoor' motion sensor. Any to recommend?

As for the shock sensor, will any slight vibration triggers it? Eg. a tennis ball hit the window but the window does not break.

Hi cwt,

Okay, you say this a commecial project but you're talking about the person walking into the living room. First of all let me explain how I do things both residentially and commercially.

Residential: I typically recommend door opening sensors on all exterior doors with the exception of the garage overhead door. I recommend opening sensors on all ground level windows and windows on the second floor that have a roof ledge below them. Then I recommend one or two motion sensors in the "traffic pattern" of the house. (The "traffic pattern" is the part of the house the intruder would most likely have to pass thru while the are running around). I don't really like using motion sensors that much so I like to use floor stress sensors as long as I have an open basement ceiling below. I reserve motion sensors for last resort. Now I program my systems so the motion sensor or interior devices are always bypassed. I instruct the customer to only use the interior devices when you are leaving the premise. When they come back home, they disarm the system which automatically bypasses the interior devices and then if they want, they can re-arm the system with only the perimeter devices on. You have to keep things simple!!!

Commercial: I put opening sensors again on all perimeter doors including overhead doors. Then I carefully place a few motion sensors to pickup someone moving around inside in key areas. If the customer has a specific valuable area(s) they I place more sensors to cover those areas. When the customer arms the system they arm everything and when they disarm it they disarm everything.

I use a security control "platform" that gives me alot of programmability. I can use my smallest to the largest panels in residential, commercial, or industrial applications. Today it's all in knowing and understanding the features the system is capable of doing. I always start with a conversation with the client to find out exactly what it is they want to accomplish then I go from there and present my plan to them. I go over the programmable features that I am selecting and how they will work for them. And on top of everything else, I let them know we can always do more down the line. All of the systems I install have modems built into them so I can call up the panel and make any necessary changes. Some of our systems have a 255 event programmable clock. The panel can be programmed to carry out an event years away if need be or it can be set up to happen only on holidays. We can program relays and/or X-10 devices to turn things on and off on various schedules. I'm using some of my systems in schools to control magnetic locks on doors. An if they need a schedule change I just call up the system and make the changes without having to waste gas driving there.

Whew! What a load. Hope this helps. Let me know if I can be of any further help to you. By the way, where are you? I'm 25 miles Northeast of Cleveland, Ohio in Mentor, Ohio.

Regards,

BobK

Wow..thats a whole lot of explanations..haha..
Since my title is burglar alarm system for the house..so it should be a residential alarm system. My word 'commercial' is in terms of selling the system to customer. Maybe i use the word wrongly..lol..

Your 'opening sensors' refers to? And the 'bypassed' refers to?

Actually i am not quite into these sensors, just a newbie..so i might not understand some terms..hope you understand me..

BTW, i am from malaysia..thousand thousand of miles from your place..hahaha!!

Hi cwt,

The term opening sensors refers to a switch built in a plastic housing that is installed somewhere on the door or window that when the door or window is opened is breaks a circuit. Opening sensors are typically "closed circuit" type devices. This means that while the door or window is closed, the circuit is complete and current can flow through the switch. These switches can be a one part device or a two part device. A one part device usually has a housing with a plunger sticking out. The device is mounted on the hinge side of the door so when the door is closed the plunger is pushed in and the circuit then becomes closed. The two part switch consists of the switch and a separate magnet. When the 2 parts are within 1/4 to 1/2 inches of each other the circuit is complete and a current then flows through the switch. If you go to www.amseco-kai.com/products.htm click on BURGLAR you can then look at different types of magnetic switches, glass breakage sensors, just about anything you are asking about.

Bypassing is a term where you tell the alarm system that you don't want this sensor or group of sensors to cause an alarm when you arm it. This bypassing procedure then prevents any alarms to occur on these devices until you disarm the system.

If you go to www.napcosecurity.com you can look at some of their systems and get product descriptions that will help you understand some of this better. They have a button at the top of the page labeled SENSORS. Then click on IQ PROFILER. This will take you to a page that tells you about the motion sensor I was talking about with the built-in false alarm library.

These two sites should prove a bit more helpful. If you need more info, just let me know.

Have anice day!

BobK

Hei..is there any circuit connection for the magnetic switch? I want to understand how the thing works. How it acts during NC? How it acts when it is open?

Added after 3 minutes:

Which type of motion sensor is suitable to use as perimeter detector?

Hi cwt,

A NC or normally closed switch in the alarm business is a switch that is open when there is NO magnet near it and closed when the magnet is close to it.


______/ ________ An open circuit switch symbol

There are inputs on alarm control panels that we call "zones". Zones stands for areas of coverage. Some panels have as few as 4 zones and some panels can have 8 zones on the main board and then be expanded out up to 255 zones depending on the panel selected and what your application calls for.

The are 2 terminals on the control panel for each zone. These are typically a high side and a low side. The low side is ground. The Normally closed switch would be wired between these 2 terminals. This forms a loop.


High side terminal O--------------o---o---|
| ] loop
Low side terminal O-----------------------|

Additional NC switches are wired in series with the first one so that the wire goes in one side and goes out to the next switch then finally on to the returning terminal on the control.

There are variations of this setup depending on the system. We now have mostly resistor loops whereby we can have both open and closed circuti switches on the same loop and the resistor more commonly called the EOLR or end of line resistor provides supervision of the wiring and helps detect grounding of the wiring which can jump out some sensors.

What do you mean what type of motion sensor is a perimeter sensor? Are you looking for an outdoor type of sensor? Motion sensors are normally used inside the home and they are for spot detection. They look at a specific area and detect movement in that area. To ask a sensor to cover alot of area is asking for false alarms. That's why microwaves and ultrasonics are not used anymore by themslves. They are called volumetric type sensors because they cover the whole area, wall to wall and ceiling to ceiling and are subject to interference by many things.

Take care,

BobK

Ya..i was refering to outdoor sensor. I have come across an outdoor sensor..

**broken link removed**

That means we no need to have any outdoor sensors?

Hi cwt,

Smarthome is a company that sells lighting control equipment as their main products. Yes they also sell a few alarm systems and component to Do it Yourselfers. The sensor you were looking at is for lighting control, not an alarm system motion sensor. Please understand that alarm system components are made to a higher standard because there is a presumption that the police will be notified when the alarm goes off. Because of this alarm system components must be made AND INSTALLED so as to prevent false alarms. This sensor you were looking at can trigger from flashes of bright light such as car headlights and lightning and can also trigger from animals walking around in its field of view.

Now I need to ask if you want an alarm system for the ouside perimeter of the house or the house itself, meaning doors, windows, etc.?

BobK