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Ringer triggred curcit

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New Member
I am trying to build a curcit that is triggered by a cell phone ringing. The trouble I am having is finding something suitable to sense the cell phone ringing. I have tried to use a peizeo for this. IE: when the phone vibrates it causes the piezeo to vibrate. It seems though that the cell phone does not have enough accelreation to cause the piezeo to have any voltage. I also tried to use a photodiode but that is not working eather.
Can someone suggest something to use or a better way to use the two things I am trying to use?


Well-Known Member
Either should work fine. If you don't post your schematics, however, nobody can tell you what's wrong with them.

Please post your schematics and with any luck, someone can tell you what you're doing wrong.

Note that you might not get a lot of responses, since it's all to easy to imagine a cell-phone trigger being used to detonate a bomb, and nobody really wants to tell somebody else how to do that.



New Member
C1 2µf
R1 250kΩ
R2 500kΩ

Out high ~1 second
Out low ~0.7 seconds

SW1 pressure switch that the phone sits on to activeate curcit
SW2 ringing sensor (I would like for this to be a switch, that once activated, to stay closed until SW1 is opened.)
I hope this helps some.

The trouble I am having is finding a switch for SW2 and figureing out which to use, a piezo or a photo dector.

With the piezo, I can't seem to find one that is sensitive enough to feel the vibrations of the cell phone. With the photo dector, I'm not sure if what wavelength to go with and which type. IE transistor, diode or what.


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