voice activated vibration

[Rikotango]

Hi there, first time here, if this works that would be real cool.

I am looking for either buy a device or build a device that would vibrate at the sign of a little sound.

The smaller the device the better. I would like the vibrating surface to be the size of a quarter, a nickel or a dime even, however, a device with the size of a wrist watch would also do.

I know there are vibrating alarm watches out there, those devices would be great but i would like it to vibrate when the device hears a sound. vibrating watches are vibrating alarm that you have to set a specific time to activate.

the sound could be as faint as a cat scratching on the opposite side of the door or as loud has a harley passing by. and the distance between the sound source and the device could be as small as 1/8 inches or several feet away.

any ideas guys?

Thanks
RikoTango

 

[transistor495]

You can do it by constructing a high-gain/highly sensitive microphone amplifier circuit which triggers a monostable 555 timer which has a tiny vibrator motor as the load. Can be made in a tiny package.

You can experiment with different gain of the mic-amp to suit the sensitivity of operation. However I doubt with the cat scratching thing... if it is that much sensitive then it won't take a rest. Start with a hearing-aid circuit

 

[alec_t]

One problem will be that the microphone will detect the vibrations generated; so the vibrator will never turn off unless very selective filtering is applied to the mic signal.

 

[transistor495]

Good thought, there are a couple of quick(can be dirty) analog solutions comes in to mind other than complicated filtering:-

*) Mic-amp circuit powered by the transistorized switch driven by stable mode of the monostable so that the mic is switched off when 555 is triggered. This should be experimented to find the effect of motor inertia..

*) Extra timer delayed switch-off for the mic-amp to overcome the inertia.

In short the mic will be deaf while the vibrator works.

I think it can overcome the self-triggering problem

 

[audioguru]

Use most of a "whistle to find my keys" product. Instead of producing a beep it turns on the vibrator motor.

 

[Rikotango]

Thanks guys for the responses.

transistor495 - that sounds good except by the time I am done with all the electronics that gadget will be much larger than what I would like it to be, dont you think?

audioguru - I couldn't find one that vibrates instead of it making a loud sound. Do you know of a link that would show me one or better yet i can buy one?

Thanks,
RT

 

[transistor495]

I doubt with the battery life of those vibrating alarm watches which use button cells.

The 'whistle key finder' gadget is supposed to be give an audible alarm, not a vibration, right? If you want to modify it then you may replace the beeper with a vibrator, but again I doubt if it can give enough current to drive the motor! Also it responds to particular frequency preferably a loud whistle to make it triggered. It is not sensitive for your application. You may not be able to modify it for higher sensitivity because it might use a COB for small size for a key chain.

You should make the whole electronics to suit your requirement I think. The above solution which I've given can be made in a mobile phone sized version, and need a good effort.

Side note:- Reviews on 'whistle key finder' product. Interesting:-

https://www.amazon.co.uk/Tobar-Keyfinder-Keyring-Whistle-Activated/dp/B000246JIQ

Pretty as expected

 

[audioguru]

A cell phone or pager vibrates with a tiny motor swinging around an unbalanced weight.
RC model airplanes and helicopters use these tiny motors and replacement motors are available at hobby stores.
Here is the motor in some of my RC airplanes and helicopter: