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

Picture of Homemade Annoy-a-thing (Annoy-a-tron) 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!

Picture of 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

Picture of 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

Picture of 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

Picture of 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!


DannyD35 (author)2016-12-02

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

jonnyphenomenon (author)DannyD352016-12-02

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.

DannyD35 (author)jonnyphenomenon2016-12-02

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

jonnyphenomenon (author)DannyD352016-12-02

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. )

jonnyphenomenon made it! (author)2016-08-04

I made one like this forever ago. still use it today! every time it beeps I lose the game!

rah187 (author)2016-06-16

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

glomicilina (author)2015-08-01

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

monkeyracing (author)2015-05-02

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.

KG989 (author)2013-01-10

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?

JasonD17 (author)KG9892015-04-05


Jan_Henrik (author)2014-05-05

haha, very nice!

Derek Vigil (author)2011-09-05

What size of diode did you use?

J-Five (author)Derek Vigil2013-04-13

I believe it's a 1N914 Diode.

GASSYPOOTS (author)2012-03-24

na the more annoyin one is vuvulza plus fan

glansj (author)2009-11-21

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.

DavidKaine (author)glansj2010-05-30

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?

joerice01 (author)DavidKaine2011-07-02

An smd NE555 chip would work nicely with this.

beehard44 (author)DavidKaine2010-10-14

yah should work
i used 1/8 watt

raykholo (author)2009-10-10

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

krish98.sai (author)raykholo2011-05-23

I went to Radio Shack and got it for around 5 bucks, I hope this helps.

raykholo (author)krish98.sai2011-05-23

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).

krish98.sai (author)raykholo2011-05-24

WOW thats a great price thanks for the heads up!

cricketm24 (author)2010-12-06

If you skip the mosfet would you connect the wires to each other

Zem (author)2009-11-22

Help! D= When I apply voltage to my buzzer, it makes no sound. 

beehard44 (author)Zem2010-08-31

you need to give a frequency to the buzzer, not just plain DC

harishere (author)2009-09-30

Does this circuit really works with 3v?

aldude999 (author)harishere2010-05-25

the voltage rage for the 555 is 4.5 to 16 volts, so it should

beehard44 (author)aldude9992010-08-31

the CMOS version goes down to 2.8V minimum, but if you use the regular one, it might not work

beehard44 (author)2010-08-27

i wanted to make an SMD version of this, but when i contacted my local electronics dealer (wiltron general merchandise), THEY DONT EVEN KNOW WHAT SMD IS!!!1!!!1!!!

beehard44 (author)beehard442010-08-31

i'll just use a few SMD chips sampled and some resistors and capacitors scrapped from old electronics.

Nickel1010 (author)2009-11-08

 Could I change the interval between beeps by making the size of the 10m smaller and making the capacitor bigger?

aldude999 (author)Nickel10102010-05-25

Just change the value of the capacitor, or you could replace the resistor with a potentometer

Colonel88 (author)2010-01-30

I am going to make one of these and stick it on the ceiling in our Mrs. Blecher's class. She is old and still says Okey-doke :D

aldude999 (author)Colonel882010-05-25

put it in the ceiling and she'll never find it XD

raykholo (author)2010-02-19

I hate to bring up the transistor debates again, but the 555 can source 200ma of current, without need for the mosfet/transistor.  So the question is whether it is because of the diode and the voltage drop that it produces that the amplification is needed.  I am aware that it is not directly connected to the output pin and piezo but it is still a thought...

ANDY! (author)2009-11-22

I made one! it wistles and annoys the heck out of people. I gave it to my friend and it went bezerk  at class!

lmperkins (author)2009-11-20

Here is my version. I used a 3volt buzzer and skipped the MOSFET. I also played around with the resistor values to get a long pause and a short beep for maximum annoyance. I think it came out pretty nice. Thanks for the Instructable.


Nickel1010 (author)2009-11-08

The biggest resistor I can find around my house is 1.5m, but if I used a 100uf capacitor would the interval between beeps be about the same? I'm not sure if I'm using the right logic here..

far.peter (author)2009-11-08

Can you use a lin comos 555?

Colonel88 (author)2009-10-07

Hmmm... i did this without a MOSfet, just 555, a capacitor, and a resistor and it works just as well.

tommck (author)2009-06-23

It would be cool to hear it in action or even better to show some unsuspecting person reacting to it :)

harishere (author)tommck2009-09-30

Try you tube you will find there, i have seen it working, people going crazy, lol.

raykholo (author)2009-08-12

my finally finished product: using a normal 555 timer (not cmos), an NPN transistor and running off of 6 or 9 volts. Everything is free form built around an 8 DIP socket and the 555 was inserted when finished soldering...
my breadboarded version has the same exact circuit but a different buzzer, and can easily run off of 3 volts. That can work with a radioshack 3v battery clip. After taking the pics, i added 3 more 20k resistors to get a nice longer beep with a total of 80k ohms, and i might change around the 10m to make the intervals smaller.

U think this can work with an LED? if so then i want to use it in a new project of mine.

raykholo (author)2009-06-23

would a standard pnp transistor work instead of the mosfet?
i read the comments below about this topic, just unclear whether a pnp specifically will work.

im talking about a 2n3906, here it is on wikipedia: link
and u can find datasheets all over google


raykholo (author)raykholo2009-07-09

sorry i meant NPN

That should work well also. You will need a resistor between pin3 of the 555 and the base of your transistor (about 500ohm should work-just a guess).

sounds good i tried breadboarding the circuit today with that transistor, and it didnt work.... so i will try this out tmrw and get back to you thanks

I looked at the circuit again, and I think that you could even get by without the transistor. The 555 can source/sink enough current that the piezo should work directly connected between pin 3 and V+ Let me know!

well i cant get the circuit to work no matter what however, the output voltage is too low from the 555, so a transistor is needed the bigger problem though is the voltage ratings of the piezo buzzers i have tried it with three different ones: they only crackle at 3 volts, yet on 6 or 9 they work great...

let_it_out_org (author)raykholo2009-07-11

ahem...depends on your piezo

About This Instructable




More by let_it_out_org:Homemade Annoy-a-thing (Annoy-a-tron)"Timed Soundie" or "12 second sound grenade"!
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