The Insanity Bringer Ringer (IBR) is a diabolical little device designed to annoy and ultimately drive your victim crazy. As far as electronics go this thing is cheap and simple to make. Here's the idea:
Have you ever heard a ringing in your ears and you can't tell if its actually real or if its just in your head? The IBR's job is to simulate that. It consists mainly of a light sensitive switch and a buzzer. It rings when it is dark and shuts off when there is light. When the victim goes to bed and shuts their lights off they will activate the ringing. The victim may become annoyed and want to find the source, but when they turn on the light to start looking, the IBR shuts off. Hopefully the victim will figure its just in their head and go back to bed, starting the cycle again.
I was originally going to call it The Sleeper Beeper but it seems that name is taken for a drowsy driver prevention system. :P
Step 1: Circuit Design
I'm not that great at designing electronics but this is what I came up with. Basically the ambient light sensor (TEPT5700) triggers the 2N3904 which will turn the buzzer on or off. Ideally R1 and R2 should be pots. R1 adjusts the sensitivity of the light sensor and R2 adjusts how loud the buzzer will be.
Cue bad paint schematic!
Step 2: Parts Needed
This is what I used to make the IBR:
(1) Buzzer (easiest to just get one with an internal driver, mine is a CEP-2224)
(1) Vishay TEPT5700
(1) 2N3904 NPN transistor
(2) 1Mohm trim pots
(1) 9 volt battery
(1) Battery Clip
(1) small piece of proto board
Step 3: Build It!
I cut the protoboard down to about the outline of the 9volt battery, then I laid everything out and soldered it up.
Step 4: Hook the Battery Up and Try It Out!
I just taped the battery to the underside of the board. Not pretty but it gets the job done.
I measured the circuit current and it was drawing about 50uA in light and about 100uA when dark. I believe an average 9v has a capacity of around 500mA so this means this device can ring continuously for about 200 days. :P
Step 5: Hide or Disguise It!
Find a good place to hide it, or if you're really crafty, try to disguise it into something. Just make sure the sensor is peeking out.
Second Prize in the
April Fools Day Project: Prank Contest