• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

5 Zone Alarm System

Status
Not open for further replies.

ElectroMaster

Administrator
Each zone uses a normally closed contact. These can be micro switches or standard alarm contacts (usually reed switches). Zone 1 is a timed zone which must be used as the entry and exit point of the building. Zones 2 - 5 are immediate zones, which will trigger the alarm with no delay. Some RF immunity is provided for long wiring runs by the input capacitors, C1-C5. C7 and R14 also form a transient suppresser. The key switch acts as the Set/Unset and Reset switch. For good security this should be the metal type with a key. At switch on, C6 will charge via R11, this acts as the exit delay and is set to around 30 seconds. This can be altered by varying either C6 or R11. Once the timing period has elapsed, LED6 will light, meaning the system is armed. LED6 may be mounted externally (at the bell box for example) and provides visual indication that the system has set. Once set any contact that opens will trigger the alarm, including Zone 1. To prevent triggering the alarm on entry to the building, the concealed re-entry switch must be operated. This will discharge C6 and start the entry timer. The re-entry switch could be a concealed reed switch, located anywhere in a door frame, but invisible to the eye. The panic switch, when pressed, will trigger the alarm when set. Relay contacts RLA1 provide the latch, RLA2 operate the siren or buzzer.

 

gbadex

New Member
hi

hello
my name is toye and i'm a student at a uni in Nigeria, pls i'd like to know if you help me out on a simple project..SMOKE DETECTOR; kindly get accross to me if you possibly can.thank you
 

Thunderchild

New Member

Nigel Goodwin

Super Moderator
Most Helpful Member
Thunderchild said:
u damn copycat this is located at http://www.free-electronic-circuits.com/circuits/5-zone-alarm.html and so r lts of other diagrams in this section and they r linked to by the forum anyhow !
What makes you think they weren't copied from here?. The posting date here is 2002, how long have the files been on the other site? - the only indication on 'whois' is that it's a VERY recent domain!.
 

audioguru

Well-Known Member
Most Helpful Member
I found my projects copy-catted all over the web, usually at sites that I have never been to before. I don't care if they "steal" my designs because they keep my name on them. :lol:
 

Zeshan

New Member
hi

i have a question.. u know near by key switch u have a circle.. can u tell me plz what is that.. mean which electronics symbol is that... plz reply me as soon as possible.

thz & regard

Zeshan
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Zeshan said:
hi

i have a question.. u know near by key switch u have a circle.. can u tell me plz what is that.. mean which electronics symbol is that... plz reply me as soon as possible.
It's a siren or buzzer, it's mentioned in the text.
 

Zeshan

New Member
hi

thx 4 ur kind info... just 1 more thing.. u know near by transistor... is it relay again or what :?: .. plz let me know...

thx & regard

Zeshan
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Zeshan said:
hi

thx 4 ur kind info... just 1 more thing.. u know near by transistor... is it relay again or what :?: .. plz let me know...
Again, the text clearly calls it a relay.

I notice in your diagram you show two relays, why is that?.
 

bloody-orc

New Member
he uses 2 relays cause he uses relays that have only one contact pair. in the schem that is given in the beginning there is a relay with 2 contactpairs and therefore only one is needed. he might noh have understood that.
 

Zeshan

New Member
hi

hi

i m in college n studying electronics.. i just want to do some practice so it will help me in future... if this circuit works then i ll modify it... as i told u i constructed but its not working somehow. I tried to construct th ecircuit as presented. can i ask wot type os relay is that.

thx

zeshan
 

Zeshan

New Member
hi

hi

i constructed this circuit on electronic workbench but its not working.. any idea why.. pls tell me any possible reasons..

thx

zeshan
 

Mike - K8LH

Well-Known Member
audioguru said:
I found my projects copy-catted all over the web, usually at sites that I have never been to before. I don't care if they "steal" my designs because they keep my name on them. :lol:
Very interesting... Do you have an example I can look at, I'm very curious?

Regards, Mike
 

haka

New Member
normally this is use for wat? can show me some title ? hehe.. cos i would to do it.. as my project.. hehe.. can i do da?
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top