If you don't like the first answer, ask the question again... Sound Impact Sensor

sunblock

I can't (repeat CAN NOT) seem to get the Sound Impact Sensor to NOT work when powering it from the 3.0-3.7V range. And since I'm not a 50 lbs brain on this electronics stuff, can someone explain why this works? I realize from the ealier post that it is probably on the ragged edge of the electrical specification for the device--and some would say SHUT UP, its working so move on--but it bothers the heck out of me. Is it the current I'm pumping thru the the circuit? Can I eliably use it this way? Can I use a Cap to suck up enough juice to keep it fed with 5V? Or do I need another power supply from the battery just to feed this thing? But mostly, I've tried all of the batch that I ordered, as well as the ones I brought back from AFGH and they all perform the same at "under voltage." But s a programmer, if it says 5V, and nothting else, then ^$#%#$ it should not be working at 3.0-3.7.

Christof Eb.

Hi, what's the problem?
If you look at the schematics, which are provided by friendly Parallax, you can see that there is a microphone, a transistor and a ne555 timer. They seem to work at 3.0 volts. You can have a look at the datasheet of the timer.
Christof

Phil Pilgrim (PhiPi)

Think back to the rules of logic. "If you supply 5V, it will work," does not imply, "If you don't supply 5V, it will not work." But, as is typical with electronics, deviating from the spec may not provide reliable operation under all conditions. Without a spec sheet that characterizes the module at 3.3V, and absent a documented history of reliability at that voltage, you're pretty much on your own to determine whether it's useful to you at that voltage and under the conditions to which it will be subjected.

-Phil