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Science Rocks!

Door Alarm


your results

Sent in by:
Kimberly of Brooklyn, NY

Don't be alarmed when visitors BUZZ into your room.

Materials Needed

  • buzzers
  • batteries
  • cardboard
  • wire
  • aluminum foil
  • paper
  • magnets
  • any other materials you can think of
  • a door



  1. Check with a grown-up before you begin.
  2. Use whatever materials you can think of to build an alarm that will alert you when someone enters your room.
  3. Remember that an alarm is a special switch that is closed or opened by someone who doesn't know the switch is there. The alarm will sound when the circuit is completed.
  4. If your alarm doesn't work, try re-attaching the wires from the buzzer to the battery. The red wire needs to connect to the positive end of the battery and the black wire needs to connect to the negative end.

Once you get your alarm to work, let us know how you designed it. What makes it go off? How does the electrical current flow through it? Did you first try a design that didn't work? How did you change your design to make it work better?

Some of your Results

Sergio, age 10 of Richmond wrote:
The door alarm work again.

Jonathan, age 9 of Surprise, AZ wrote:
It was so cool! I made it so when you open the door the wire touches the paper clip and BUZZZZZZZZZ! Thanks ZOOMers!

Aileen, age 7 of Norwell, MA wrote:
cool! it freaked out my brother even though he's 14 and much older than me

Kate, age 10 of Saint Paul, MN wrote:
my brother freaked out.

Aaron, age 13 of MO wrote:
Cool! it scared my sister when she opened it. very funny.

Michel, age 8 of Chicago wrote:
i hooked it up and it worked! IT WAS SO COOL!!!

Chrissy, age 10 of Orangeburg, SC wrote:
When I first tried it and it did not work, I stripped the wires back on the 9 volt battery so that I would have more tip. I tried red to black & black to red on the poisitive & black on the negative I got a clicking noise with 9 volt. With the d it was a low click, and the winner was c it made a high click & buzz. HA HA HA I LOVE MY NEW ALARM, THANKS ZOOM & Kimberly.

Anne, age 12 of Bristol, England wrote:
It so... amzing. My family use 2 butt in 2 my room without me noticing. But not anymore since I put the alarm.

Jesse, age 12 of Mandeville, LA wrote:
The door alarm was great. I mounted it on my door. Then my dog hit my door and opend the door and the alarm whent off. IT WAS COOL!!!

Hannah, age 15 of Augres, MI wrote:
nothing happend, we did it just like you said, it was stupid we even re-did it like 3 times. it was bad

Priyan, age 14 of Chennai wrote:
there is no circuit given

Cam, age 7 of Saint Johns, MI wrote:
I made it with two big fat books, Tin foil, Spy kit buzzer, and a magnet. "Beeb beeb beeb beb beeb beeb Beeb" that is what the buzzer sounds like. and it worked!

Brian, age 14 of Fort Lauderdale, FL wrote:
It worked out great. Now my little brothers cant come in.

Estabon, age 4 of Lake Charles, LA wrote:
Omg, it wuz so asum. My sista was trying to take my stuffed possem. So I wuz in da kitchen watching Crocodile Hunter and eating Pork rinds when I herd the alarm go off. I ran up sters and saw her crying by my door. I luaghed and said "You shouldn't have gone and done that". Then I went outside to catch lizards.

Tyron, age 12 of Harvey, IL wrote:
It ain't work. We tried and tried and my dad almost lost his mind... Trust i tried hard and it doen't work

Marissa, age 12 of NY wrote:
it was very loud so when I have a suprise for my sister in our room and I am not there I hear the alarm and got her.

Bradybill, age 14 of Las Vegas, NV wrote:
i had broke the switch so nothing worked, but I tried to fix it and to get it to work. I was tring to make a door alarm but my plans didnt work.

Mariah, age 15 wrote:
It rang loud! I was scared myself

Sydney, age 11 of Brampton, ON wrote:
Well it activated and now my brother cant sneak into my room without getting caught

Tate, age 8 of ME wrote:
well it worked and it was cool

Candela, age 11 of Orem, UT wrote:
It totally worked it was awesome

Jessica, age 13 of MI wrote:
we did it in class for a lab experiment. I was so amazed it worked it scared me when it went off.

Dyshiki, age 11 of Peoria, AZ wrote:
o my gosh this alarm is da best thing in the world like totally awsome I was in the kitchen eatn a tuna sandwich wen I heard da alarm go off it wa my annoying brother staeling my make up it reaally wrks o my gosh

Meaghan, age 11 of Kitchener, ON wrote:
i toddly choght my sister when she was trying to stell somthing from my bedroom and my alarm went on so I stoped her

Tasmia, age 11 of Portland, OR wrote:
Well, my older sister always used to come in and bother me... the first time she came in while the alarm was set... AHHHHH!!! She was gone in a second! I was really happy with the results.

Drake, age 13 of New York, NY wrote:
i changed the door alarm a bit. it took an old tv set and Vcr and hooked it up so every time someone comes into my room iit sounds like a minigun going off

James, age 10 of Labury, IL wrote:
i decided to change the design a bit and include a few laser tripwires and photo cells(CDS) and a mobile phone.. as soon as my little sister went into my room my phone started ringing and it came up on screen "room breich" XD

Emily, age 6 of NC wrote:
my dog was going to the door of my bedroom the alarm made him go away

Allison, age 7 of FL wrote:
My sister came in and set it off!!!

Mariah, age 7 of York wrote:
one day my sister wanted to steel a toy the bell was so loud my sister sreamed and ran away.

not yet implemented