Help finding sound device to place in ammo can?

[+Cache Liberation Front]

Hi all,

 

We're doing a scary night cache, and want to place some kind of device inside the ammo can, so that when it opens, a loud noise will go off. We'd perferrably like a scream or moan or something of the spooky sort, but any kind of alarm would do.

 

Most of the battery powered magnetic alarms require you to flip a switch to deactivate, which won't work since the device will be inside the can.

 

Any suggesitons/links would be greatly appreciated.

 

Thanks!

[+JohnnyVegas]

I have used window screamer alarms in caches. THey are small and one side has a magnet in it. You connect the part with the magnet to the door of the container so that it is in contact with the alarm, when the contact with the magnet is broken the alarm starts. The hard will be setting the two parts up in the ammo box so that they are in contact when to ammo box is closed. I ended up building my own boxes out of wood.

I recently saw a four pack of these for $8.00 at Frys electronics (Outpost.com).

You can even fit these alarms into an altoids tin.

[+Cache Liberation Front]

I have used window screamer alarms in caches. THey are small and one side has a magnet in it. You connect the part with the magnet to the door of the container so that it is in contact with the alarm, when the contact with the magnet is broken the alarm starts. The hard will be setting the two parts up in the ammo box so that they are in contact when to ammo box is closed. I ended up building my own boxes out of wood.

I recently saw a four pack of these for $8.00 at Frys electronics (Outpost.com).

You can even fit these alarms into an altoids tin.

 

Thanks!

 

How do the cachers reset the alarm, though? Don't the contacts have to be touching (i.e. the box closed) to reset the alarm? Or does the alarm go off once the contacts are touching again? Or is there a shut off switch, which you have to turn back on to reactivate? Hmmm.

 

Maybe I'll just buy some and try 'em out.

[+GreyingJay]

Aren't there motion-activated Hallowe'en decorations at Wal-Mart and the like? Where you pass by or wave your hand or push a button and the character moans or cackles or screams or sings as required.

 

The sudden light from opening the ammox box might well be enough motion to trigger the device.

 

You could probably also rig a reed switch or contact switch (Radio Shack) to act as the on/off switch for something like this, or an alarm, or whatever. With a reed switch, a magnet fastened to the lid keeps the contacts open (you would need to buy a normally-open switch) until it is taken away (i.e. when the lid swings open). With a contact switch, there's actually a little lever (possibly with a roller attached to the end of it to protect it) which is kept physically closed by the lid, but springs open when the lid does.

 

Another option might be to have the "alarm" externalized in your environment (hidden box nearby, hidden wires). You could use a magnet hidden in the cache box, or the weight of the cache box itself, as a trigger -- when the cache is removed from its hiding spot, the alarm goes off.

Edited September 7, 2006 by GreyingJay

[+briansnat]

I don't have any ideas, but I'm glad I don't live in your area.

[+Cache Liberation Front]

I don't have any ideas, but I'm glad I don't live in your area.

 

Thanks for your helpful contribution (and the bump).

[+Bear_Left]

There's lots of proximity alarms (often used on shopfloors to trigger a sales spiel when someone approaches) that use changes in ambient light to trigger them. Some of them are also voice recorders (I have three or four of them for just this purpose!)

 

Record your scary/shocking sound effect and put the device in an ammo can. Even if it's dark, they'll shine a torch in to see the swag and logbook!

(Of course, hi-tech cachers using image intensifier goggles won't trigger this one, but there won't be many of them...)

[+Team Teuton]

Aren't there motion-activated Hallowe'en decorations at Wal-Mart and the like? Where you pass by or wave your hand or push a button and the character moans or cackles or screams or sings as required.

 

The sudden light from opening the ammox box might well be enough motion to trigger the device.

 

Actually, I think these are sound activated. But that would be the perfect solution to the problem. They're battery operated, cheap, aren't too loud and Halloween's coming soon.

 

If the 'guts' of these things were mounted inside an ammo can then the sound of the can being opened would be enough trigger to activate them.

 

Good idea.

[+theUMP]

We had a personal alarm (pull the cord, removing a pin, and the thing make a really load screech until you put the pin back in) as a swap in a cache of ours.

 

It was a little naughty, because the cache was in a disused railway tunnel, about 150m from the light at either end...

 

The first finder pulled the string to see what this little plastic box did. And nearly soiled himself!

 

You could attach one of these to the top and bottom of a cache container, or to the logbook bag. It'll make a row until the cacher a) picks up his torch from where she dropped it in shock and figures out that he has to put the pin back in before she gets any peace!

[+Mudfrog]

We have been trying to rig one up ouselves. I put the batteries and sound device under a false cover inside an ammocan with a microswitch to activate it mounted at the lid. It works great except, i would like it to automatically disable the sound after a few seconds so the cache finder wouldnt have to contend with the noise while looking through the cache. Then when the lid is closed back up, things would reset on their own. I'm sure this can be done with electronics (a time delay of some sort maybe?) but i havnt found anything that works with my application. Any ideas out there?

[+brdad]

I used a small board from a talking picture frame. Took it out of it's box, and placed it inside a small plastic box on the inside cover of an ammo box near the hinge. I rewired the puchbutton to a normally closed reed switch (magnetically activated, like a window alarm switch, which was also inside the box. I then glued a magnet to the inside of the ammo can near the voice box location with the cover closed. So, if the lid is closed, the switch is open, once it's opened, it plays the recorded message. Once the box is closed, it resets.

I wish I had pics of it all in place, but can't locate them. Here is the circuit board, though:

 

Edited September 9, 2006 by brdad

[bug and snake]

I have made two caches with sound modules in them. In both cases the modules came from dollar store toys.

Here are a drawing and some notes on how to get the desired result. I have not given complete details on mounting the parts, that is up to you but it is not hard to come up with something that will work.

The question regarding re-setting the sound when closing the lid is easy to deal with. First, remove the original actuator switch from the circuit and place a short circuit where it was. At this stage, if the batteries are connected then the module will sound continuously. (some toys sound modules have a set of sounds that they send out and then they stop)

Now use a microswitch (Radio Shack - inexpensive) to switch the battery power to the unit. Be sure to use the NC (normally closed) and the COM (common) terminals to do this. Ignore the third terminal. This configuration will ensure that the module is active when the box lid is not holding the switch lever down. This mode of operation is the best to ensure that the batteries will last for the longest time.

Be sure to protect the various parts of the sound system from short circuits and other damage in a way that works for your cache.

 

Email or PM if you have specific questions.

[heckle]

What about getting one of those birthday cards where you can record the message and mount it insode the can. When the lid opens, it reads out the message/coordinates, etc... Hmmm... I think I may do that myself.

[+Mudfrog]

This mode of operation is the best to ensure that the batteries will last for the longest time.

 

Is this why you put the microswitch in series with the batteries? It looks like you could use the batteries in the original battery holder and put the microswitch in place of the original actuator switch...

 

I can see this working pretty well with stuffed animal type sound devices because they play for a bit and shut off on their own. But i was wanting to use something, like a piezo horn or something like that, which doesn't shut off by itself. In otherwords, it would have to be something external to the sound module that does the resetting.

 

Has anyone run across a low voltage DC powered device that is user adjustable for the length of time that it sends power to an external device, that resets itself after this set time, and that does this all over again when a switch to it is closed again?

[+DocDiTTo]

I found one cache that used a sound mechanism. It was routinely broken by cachers trying to immediately shut it up, as it was a loud alarm. Something that makes a noise and then stops by itself wouldn't be so bad, but something that continues to make a noise until it's disabled will probably be permanently disabled by one of the finders. Expect to perform frequent maintenance runs on such a design...