Creating a compressed air effect

[Zzz]

Need some help on creating an effect...

I wanna make a "compressed air" effect. You know that "PSHHH" sound that can come out of buses? That.

If you've ever seen one of these http://www.bernberg.se/shop/fritid/dusch.jpg then you might know what I'm looking for more specifically. That is a portable shower, you pump it up, creating pressure inside > water will come out and so. You can also at the back of it (the side you can't see in the picture...) pull a thing like a valve up, and let the pressure out. The effect achieved there, when pulling the valve up, is what I'm looking for, but mechanically created. In other words: I don't wanna stop and start pumping up pressure inside a bottle...

I've got some space to work with... not anything huge, but big enough hopefully.

So, is there like some sort of mini pump that automatically will let air out when X amount of pressure is reached? Or something. Throw what you've got at me.

If you get what I'm talking about, but don't know any way to achieve the effect, maybe you know another word for what I'm trying to achieve. If you do, I'd be happy to hear it so I can look around some more :]

 

[terryr]

Re: Creating an compressed air effect

How about a high pressure cylinder with a hand valve? Something like an air hose nozzle that allows a quick pssst.

The cylinder could be from paintball.

 

[Zzz]

Re: Creating an compressed air effect

Could work, but I'd rather it'd be something functioning automatically without me needing to do stuff all the time for it to work.

[Edit]: It's more of a "background detail", not something you stop to do now and then. Imagine a robot that "PSHH"'es once in a while automatically. I want to create something like that, functioning automatically.

 

[Fly4v]

Re: Creating an compressed air effect

How about a can of compress air used to clean computers, RC servo to depress the top, and a circuit card to control the cycle of discharge?

 

[TheNickFox]

Can I ask why this has to be mechanical instead of say...electrical?

You could get this same effect by hacking one of those birthday cards that records a message, just recording the sound effect you want.

If you're going down the complex road of building some crazy contraption to measure pressures and manually activate a physical thing, why not just simplify your life and do it as a sound effect?

Is there any reason this needs to be done mechanically?

-Nick

 

[propnoob74]

Have you try rigging one of those air freshener thingamajig; the one you mount on the wall and they press the air freshener can in intervals of 10, 15 and 30 min, I think you may be able to tweak it to you convenience....

Walmart.com: AIR WICK White Freshmatic Ultra Gadget: Household Essentials

I'll bet you can take apart one of these and use a can of compressed air and make some magic....

 

[Genises]

were you to want this done wholly mechanically i would suggest syringes with an internal flap, but that's only if you can find a way to have the plunger pushed down when you want the noise and pulled up when you want to refill the canister, but be forewarned this will not be loud...

Personally, I agree with Nick, strings reaching to your elbows and knees connected to the play button on a cheap voice recorder with the sound effect recorded ought to be enough.

 

[Zzz]

Hold it: English isn't my first language, sorry, didn't think that far.

I only want it to function on its own, electrical would be awesome too. I just want it to be able to create the effect on its own, not me needing to push any button and so on. I'd love it if it could be made "real", no simple sound effect since I've got some parts that I'd hope I'd be able to get to move when the air is released (nothing major, just a part that kinda goes up a bit when air released. Won't bother me if this wouldn't work)

 

[Zzz]

Shameless bump.

 

[Honus]

It would be pretty simple to do. Just have a microcontroller programmed to turn on a solenoid valve at a precise interval. The valve would let air escape from a compressed air cylinder.

For the microcontroller you could use an Arduino or BASIC Stamp or whatever. This would connect to the solenoid valve using a transistor (TIP120 is pretty common) so that when the controller tells the output pin to go HIGH the transistor sends the signal to the solenoid valve and lets the air escape for a predetermined time, wait a few seconds (or minutes) and then trigger it again. This would happen over and over until you turn it off.

 

[Zzz]

Thanks! I'll look into that :]