A reliable (modified) alarm clock that will wake the dead. I put this together after having several wind-up alarms break on me. It's basically an electronic alarm clock modified to trigger an alarm bell. Since I'm pretty much comatose when I sleep this is just what I needed.

Step 1: Get Materials

Here's what you need to make this:
1.Alarm clock - mine is a cheap one that I got from Walgreens. It gets it's power from the mains and has a 9v battery for backup. I don't remeber how much it cost but it was probably less than $15.

2.Some basic knowledge of electronics and construction techniques. (really?)

Step 2: Get Materials

3.Some sort of doorbell or alarm bell that is loud - The electromagnetic kind work well.(If you use something different then you may have to change wall wart #2) I got mine from eBay. It's like the buzzer type of old doorbell but with a hammer and bell attached.

Step 3: Get Materials

4.(2) Wall wart type power transformers. #1 is 9v DC output (somewhere around 350 ma) and #2 is 9v AC (@500 ma).

Step 4: More Materials

The rest you need is:

5.Relay - 12vdc coil, and able to handle your bell supply power.

6.555 Timer - I think pretty much any standard variation will work.

7.2n3903 Transistor - (this may be superfluous)

8.1 M Ohm Resistor

9.Some hookup wire

10.Extension cord - this is optional, but if you use one make sure its the kind with 3 outlets so you can plug in the clock and two wall warts.

11.hardware and some sort of case to put it all in


solder, some sort of support (pcb, breadboard, etc.), soldering iron, multimeter (or just a voltmeter), wire stripper, screw drivers, a knife maybe

Step 5: !Warnings!

OK, a couple of warnings:

1. Just so we're clear, you need to exercise extreme caution when working on this project. Don't work on aynthing when it's plugged in!!! I've been electrocuted many times and it's never very fun. Make sure that the circuit is insulated when it is plugged in (by a case generally).

2. The 555 chip can be damaged by static discharge. In fact I usually buy doubles for this very reason. Don't wear static prone clothing and leave the chip in it's packaging until you're ready to use it.

3.The ground shown in the schematic is a floating ground, which means that it is exclusive to the circuit and SHOULD NOT be connected to earth ground (mains).

4.I'm not that knowledgable when it comes to electronics so this is presented as I did it. There is a lot of variation that could happen with different components and some things may not work together.

I think that's it... just use common sense.

Step 6: Open Your Clock

With it unplugged, open your clock (no touchy capacitors) and solder two lengths of wire on to the buzzer disc/ speaker (where the 2 wires from the clock circuitry are soldered on). Run the two new wires out of the case (I used the power cord hole) and button the case back up.

Carefully clip the ends of the wires to your meter. and plug the clock in (sorry for the safety contradiction). Your meter should read something like 16 volts. If not then your clock may not work, although with some basic electronics knowledge you could probably get it to work. But this setup may work anyways with a range from 10v to 18v approx.

Finally, with your meter still connected, get the alarm to go off. The voltage should drop to around 7-5v when the buzzer sounds. If so, then you have a winner.

Step 7: Wire It Up

(you may want to breadboard this first to make sure it works.)

Construct the circuit using your favorite method. and wire it to the other components as show in the schematic.

Step 8: Button It Up

Make a case for the guts (wood works well for this). I made a box with the necessary holes and put the circuit, relay, wall warts, and outlet end of the extension cord in there. I mounted the bell to the top with screws and the clock with velcro. That's pretty much it...

Step 9: Take It for a Test Drive

Set the alarm for some time in the future and enjoy!
REALY!!!!,       no one comented on this pic at all,     REALY!!!!   ;<]
<p>JFC, man. You want comments? Try spelling as if yer life depended on it...</p><p>Apologies. To be nice, &quot;that's a lovely picture. Where'd U find it?&quot;</p>
@sgamer1771, If you want expieriance, just fiddle arounf with old, or broken stuff to see what it does.<br />
thats how i became a pro at fixing things
@sgamer1771, really is this youtube, comment on the persons comment
Alarm clock + 1000 watt amplifier + Lots of speakers = Angry friends&lt;br/&gt;<br/>
Angry friends = Ex Friends...<br/>
Angry friends=You're f***ed.<br/>
not really...
He would be, if I was the avenging friend. 220V flowing through aluminium tape under the sheets. Never fails!
Well...that would be kind of a bad idea, as you would need to arrange them in a way...besides, anyone doing that to you would never have been your friend...Anyways, Something having to do with flyback transformers is more fun :D
&nbsp;Fly back transformers? Please.. its all about the 30 alarm clocks built into the walls (._.)
make the list[s] in paragraph form<br /><br />the numbers get confusing &gt;:(<br />
I'm a personal fan of some of the Rube Goldberg "wake yourself up" machines, where the alarm goes off and effectively drops a brick/bucket of water/cat etc. on your head. For the most part though, I tend to wake up fairly easily with a generic alarm clock set to buzz, or my cellphone set to 1812 Overture :) vibrating alarms help too. If someone comes in there to wake me up though, I'll be in a bad mood allll day.
GOJIRA! :D That's a way to wake up! :D
get a rock band record the 120 decibel increase volume wake up
ha ha you think you could connect an electric airsoft gun so it shoots you when the alarm goes off?
Wire a solenoid to the clock and mount it in the trigger of a .50 cal rifle loaded with blanks! :P
me and my friends have a proposal to make an alarm clock that sack whacks you repetitively until you get up. and another one that has a hydrolic ram under your bed and rams you into the ceiling where there is a big fist....
FRESSER WROTE A BOOK DOWN THERE!!! XD but it explains alot
i never use alarm clocks, the noise always gives me a panic atack in the morning. instead, i set the alarm on my cell and put it on vibrate under my pillow. when it goes off it shakes the whole bed XD
*trys method*<br/>*hears something being crushed*<br/><h2>XD!!!</h2>
and one time i did this prank to my roommates:i set my alarm to midnight and then *12:59.9*BEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEP!they were pretty pissed off
WIN, Thats genius! On my alarm clock you can controll the volume of the buzzing, it can get quite extremley loud :P
I actually didn't do it because the roommates included some kid who beat up whoever he was pissed off to
All of those images look like a vector, where did you get/make them?
I'm sorry, but why are you using the DC Transformer? you might as well open the alarm clock up, find the wires from the internal transformer, trace them to the PCB. Near them there should be 4 black diodes (4001 or 4004 or something like that). They form a bridge rectifier. from their rectified outputs there should be traces leading to a more or less big cap. Something around 16V 470µF (that's what i found in mine). Now simply hook a 7805 (5V regulator) to the cap. The 7805 gives you a stable 5V that you can use to power the NE555. This saves the cost of a second external transformer. You would also not be wasting so much energy through that 9V DC transformer. The best circuit would be without the 555: find the main IC (there are usually two: one for the clock and the other one is a "tiny radio") and google its datasheet. Many cheap alarm clocks use a chip called ??8560 (first two symbols change between different manufacturers). In the datasheet find the "alarm out" pin. now measure the voltage between this pin and the cap ground when the alarm sounds and when it's off. If the pin goes high when the alarm sounds, simply connect the base of you npn transistor to it (remember the resistor!) and the relay to the C pin of the transistor. If you use a relay up to 12 V you might be able to power it from the clock supply. Don't forget the diode across the relay coil to protect the transistor! This solution saves lots of space, parts (money) and energy, because you don't have to power additional parts. Unfortunately the clocks supply is usually too weak to power the bell, so you'll need that additional AC transformer. Depending on the current required by your bell you might even use the internal power supply, as the bell is not going to ring the whole day ;) (At least i hope you can get out of bed faster)
Wow, I'm loving these pictures.
how about, instead of attaching it to a bell which wakes up everyone in your house, you tape two wire ends where the bell would go to your finger, so you get shocked.
i simple wire mine up to all computer speakers
There should be a diode across the coil of the relay, to prevent it from zapping the transistor. When current is removed form a coil, it makes a spike of reverse voltage. That is how they make the high (~35,000 V) voltage for the spark plugs in cars from a mere 12V battery. Diodes have a line on one end. Put that end on teh transistor end of the coil, and he other end on the other coil wire. Most bells can run form DC, so just use the same power source as the rest of the circuit. Put a diode on that too, with the line on the plus side.
could someone make an instructable on that and then I can make big sparks??<br/><sup>sorry to comment on an old post......</sup><br/>
That is the principle of the spark in car engines: The coil in the car is given 12 V, and when it is interrupted, the secondary of the coil produces a huge voltage, like about 35,000V. In a tube TV, the flyback transformer does a similar thing to produce the high voltage. It can be very dangerous. <br/>A safer way to make big sparks is an electrostatic generator. They can make higher voltage, but with less amps, so they are safer. Here is one nice project: <br/><a rel="nofollow" href="http://www.cavemanchemistry.com/dirod.html">http://www.cavemanchemistry.com/dirod.html</a><br/>I have made one, and it works great. <br/>
Yeah. It could reach back and kill the 555 as well or even the clock itself.
you could get a 80-90 decibel piezo buzzer from radio shack or the dollar store (burglar alarms) and wire it to your alarm clock
I'm not sure why the 555 is there. Is it simply a buffer between the alarm clock sound output and transistor?
try attaching it to a car horn thats what I did there is no way to get back to sleep after that :0
whoa <br/>=I MEAN IT<br/>
thx u relly achomplish my hard timz
what is a good source to start learning about electronics and contruction techniques. I know basic soldering from adding a chip, but that is it right now.
i use Jet Audio on my computer it has a built in alarm with a fade in for the music i want to listen to
I would really love to have the relay drive a robotic arm to slap and/or turn the bed upside down so my night owl brother can wake up. He's one sleeper! tsk!
I use this <a rel="nofollow" href="http://onlineclock.net">Online Alarm Clock</a> hooked up to my stereo, cranked full blast..that's loud !<br/>
Easier method: Use a clock radio. Not loud enough? Easy. Rig a bell or buzzer to a timer and transformer. I ended up training myself to auto-wake up before the clock radio goes off, because of how I hate being woken up by the alarm. It's nearly like being woken up from a coma, just like you describe. When I was a teenager, I used an electric timer and a homebrew buzzer. It worked. Digital timers can be had that are accurate enough to be used in this way. When I used the timer, it was a mechanical timer that I had to calibrate to the desired alarm time.
i wired my amp up to the clock. Boy, does it wake me.
Out of sheer curiosity, I added a 12 volt car air horn compressor with horns. Some simple transistoring, and the alarm triggers the 12 volt compressor. My wife is still mad, but I didn't sleep in that day!
the bell is the bit i cant find
Lets see..<br/>the relay and bell are probably the hardest to find.<br/>I got the relay from a local surplus store but you could find them maybe on ebay or there are some here <a rel="nofollow" href="http://www.sciplus.com/category.cfm?subsection=16&amp;category=156">http://www.sciplus.com/category.cfm?subsection=16&amp;category=156</a><br/><br/>The bell is just an old style of doorbell that will run on low voltage (not 120v) that I found on ebay.<br/>
Should be able to get everything (except maybe the bell) at radioshack.
I'm having difficulty finding the parts- where can i get them?

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