hi, in GCSE electronics, i am making a burglar alarm and I am a bit stuck on the specification, i need about 30 points and i have about 22, any ideas?

so far i have:
Design
My alarm does not need to be portable
It must alert people that the house is getting broken in to
It must be vandal proof
The keypad must be easily accessible if I use one
It must be safe to use
It must be strong
It must be a basic colour
It must be appealing
It must be easy to use
It must not be too big
It must not be too small
It must be able to be installed in the average household
It must be a basic shape

Circuit
The alarm must latch when activated
It needs to be heard by other people
All circuitry must be hidden
If using a keypad, the alarm should only be de-activated by entering the correct code in the right order
The alarm must be activated if the correct code is not entered in a certain time
Must be tested by the user regularly
Must have various sensors to cover all areas
Must last a few years (last longer if mass produced
It must not be activated by accidents
It must cover all windows and doors
Must be easy to use

Thanks in advance for any help
Mike

Thanks for the ideas the colour one was just to make up the numbers lol

i will mention in the instruction booklet "it is advisable to get yourself a greman shepard or rotwiler should the alarm fail"

Mike

It must be safe to use

lol... probably get sued!!!!

Being able to enable/disable alarm zones.
Bunch of LEDs to show sensor/zone status.

These are good ideas .... but will be quite tricky

Door chime mode option when user is home.
Selftest feature.
Auomatic lockout of a failed sensor.
Memory feature to let the user know that the alarm as tripped but had reset.

this is for GCSE not security for a bank :P lol

need at least 2 chips for a grade a or b

ive got 4 and thats just for when the front door is opened...

555 monostable>555 astable>4510 up/down counter>4511 binary to display driver>7 seg display (gives 6 seconds for the user to de-activate alarm when front door is opened before the alarm goes off)

i need to link the output from the monostable to a NOT gate then to the alarm.... im going to get stuck on that part because i want the alarm to go off after the time period (after pin 3 goes back to low) so i will need a not gate to invert the signal to high but then before the door is opend, pin 3 will be low which will be inverted to high which will make the alarm go off!!!!! oops!