Homemade Annoy-a-thing (Annoy-a-tron)




Thinkgeek.com sells a thing called an annoy-a-tron. Its basically a device that, when activated, beeps at a varied interval. While this instructable does not create an exact replica of think geek's annoy-a-tron, if you've got the materials and the know-how, you can make quite a few and deploy an entire fleet of them! :D

(please note that this is not an instructable on soldering or electronic components. prior knowledge is assumed)

Step 1: PARTS!

- 20k ohm resistor (red, black, orage)
- 10M ohm resistor (brown, black, blue)
- 10 uF capacitor
- perforated circuit board
- CMOS 555 timer (MUST be cmos / low power consumption to run on a 3v battery!)
- diode
- 3v battery (2032) & battery holder
- asst. lengths of wire
- mosfet (i use a VN10KM, others may work)
- piezo buzzer (apply current and get a beep, just the piezo element itself will not work for this)
- solder
- switch

- soldering iron
- wire cutters
- box cutter or exacto
- knowledge of soldering and electronics :D

Step 2: Nitty-gritty

the circuit diagram is shown below. hopefully it is readable.

if you've got a breadboard, lay one out first and make sure it all works!

AGH sorry! Revised schematic 4/4/09(thanks dad)

Step 3: On Perf Board and Component Leads

you can find perf board online or at places like radio shack. its really handy, and you can use an exacto or a box cutter to score along the perferation and break off pieces you need.

my project here is 11x9 holes. depending on the size of your components and your layout, your size my vary.

another good idea is to lay out your components before you cut (to know how much you need) as well as after you've cut it. knowing where things go before you start speeds up the process and prevents having to go back.

one last tip: when cutting off excess component leads, you can save them and use them to make connections to the bottom of your board.

Step 4: Final Thoughts

after you get all of your components onto your board, the bottom work begins. i try and lay the circuit out so many of the connections can be made by jumping between two adjacent holes with solder. i find the most difficult set to be the underneath work, as it requires steady hands and more thought.

hopefully all has gone well and your annoy-a-thing works! this set up i've just layed out should last about a month.

as with all little projects like this, a magnet can be added to the bottom. this will, however, add thickness, so i prefer using double sided sticky tape.

one of the things think-geek's annoy-a-tron has that this one lacks is a different length of time between beeps. this particular "annoy-a-thing" will beep about once a minute (+/- a few seconds depending on battery life).

ALSO: note that you can change the time between beeps by changing the value of the 10M ohm resistor. if i'm not mistaken, i believe a value of 20M ohm will make it 2 minutes, 30M ohm is 3, so on. (you wouldn't want to go too crazy and make it 10 minutes or something, i don't think that would work. but hey, nothing stopping you from trying!)

your comments are appreciated!



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178 Discussions


2 years ago

Would adding different value caps in parallel to c1(the 10uf cap) create a more random timing of the beeps?

3 replies

Reply 2 years ago

actually, no. When capacitors are connected in parallel, the total capacitance is the sum of the individual capacitors' capacitances. If two or more capacitors are connected in parallel, the overall effect is that of a single equivalent capacitor having the sum total of the plate areas of the individual capacitors.


Reply 2 years ago

oh yeah sorry. it has been a while since I've read wiring schematics.


Reply 2 years ago

I should mention with my design the timing isn't exact from one beep to the next. so long as it is programmed to be sufficiently long. there is enough error in the resistors, capacitor, oxford comma and power source to create a little bit of randomness to the actual timing of the pulse. (Also: this page explains briefly about capacitors in parallel or serial. http://www.allaboutcircuits.com/textbook/direct-current/chpt-13/series-and-parallel-capacitors/ )


3 years ago

Great instructable! I have a feeling that I could really drive someone insane with this...


3 years ago on Introduction

This is amazing, congrats!
i want to use it with a 9v battery can you point me in the right direction to make it?


4 years ago on Introduction

Hi, question here from an electronically challenged guy - on the original Annoy-a-tron, what is the adjustable pot for? I've messed around with it over the years but haven't noticed it doing anything.


6 years ago on Introduction

This may be a stupid question, but in the breadboard photo what are the large red 4 posted components in the top/bottom left corners of the photo?

1 reply

9 years ago on Introduction

I made a boardless version shown below. The first three pics are during construction and the last is the final product. It does not use a mosfet. The wait is about a minute with a half second beep.

3 replies

Reply 9 years ago on Introduction

Wow, those are some massive resistors.  Aren't  they a half watt and 1 watt, respectively? I was thinking about making a boardless one, but using 1/4 watt or smaller resistors.  Would they be able to handle it?


9 years ago on Introduction

any suggestions as to where i might find a cheap piezo as used here?  perhaps chinese store such as dealextreme with free s&h ? :)

2 replies

Reply 8 years ago on Introduction

I appreciate the reply, although the original comment is about 2 years old and I've found some better sources since then.

Save yourself a few bucks if you're planning to make more of these:




I'm just giving you the general pages because these places change their inventory every once in a while and I haven't bought any piezos that recently. I can vouch for goldmine's "3 lead piezo disk" - it's ok quality and you get 3 for a buck. just don't drop it or the wire leads will come flying off.

These places also have good prices on all the other components needed for this instructable. If you only want to make on order, I recommend dipmicro electronics (first link).