Small sound sensitive flasher

[Mosaic]

Hi:

I have a project to make a circuit to flash an LED each time it detects an impact.
Basically I am trying to make a pair of flashing drumsticks from acrylic tubing with a 3/8" ID.

The challenge is the Int diameter (3/8") of the clear acrylic drumstick tube.

I am thinking about a 7555 smd one shot with a vibration sensor or maybe a piezo sensor. Driven off about 3V of watch batteries.

Can anyone suggest a suitable sensor that would fit? Perhaps a low power SMD microcontroller maybe a better soln than a 7555 timer.....as it would have an ADC to sample a piezo sensor.

 

[DerStrom8]

Hi Mosaic. I'm thinking you could probably do this with just a few transistors and resistors. It may take some planning to wire together, but it should definitely fit in the space you describe. I found this schematic a while ago and thought it might do the trick:

**broken link removed**

I hope this helps!
Regards,
Der Strom

 

[Mosaic]

Thx... but that's a hi component count, although since I am driving an LED the last transistor & relay could be omitted. Voltage might be an issue. I am thinking of using zinc air PR44 type cells.
Chances are a 8 pin smd uC might offer the lowest parts count...but overall might be more expensive.

Still wondering about a sensor to fit in that diameter.

 

[DerStrom8]

Thx... but that's a hi component count, although since I am driving an LED the last transistor & relay could be omitted. Voltage might be an issue. I am thinking of using zinc air PR44 type cells.
Chances are a 8 pin smd uC might offer the lowest parts count...but overall might be more expensive.

Still wondering about a sensor to fit in that diameter.

The component count is rather high, but they are all very small. You could probably fit 4 1/4 watt resistors in there next to each other (making sort of a cylinder) and it would take up about a centimeter in length. Transistors aren't very big, and the electret mic would fit perfectly in a 3/8 inch hole. I don't think the number of components would be a problem.