Electronics Gurus

[slapnpop]

I need some help with a *hopefully* simple circuit deisgn.

I've got some piezo elements that are used as drum triggers for midi systems. I'm trying to use those to flash an LED array off of signal from the drumhead/piezo, such that the light flashes when the drum is hit.

These are the details I need:

Piezo trigger

potentiometer for adjusting the sensitivity

the out leg needs to either be strong enough to push 1amp @ 12v, or activate a relay that can hanldle it

diagnotstics LED onboard (have 12v LEDs at my disposal)

12v powered

I know we've got several electronics gurus in house. Is this simple enough to do? Anyone who could whip up a schematic of what I'd need?

 

[HaulinAshe]

Hey Slap,

Let me see if I have it straight?

You already have a piezo element/trigger for the drum.

You need to source/sink 1.0 amps @ 12 VDC.

I know squat about drums, but seems like a piezo trigger made specifically for drums, probably already has some internal support circuitry built into it. Piezo element by itself would produce a modulated current that approximates the frequency of the drum vibration. The voltage would be pretty substantial, unless the element is customized in some way.

Any chance you have any specs on the element/trigger itself? Maybe even a manufacturer's web site to look at?

As I scratch (my head), pondering your needs, it seems that the frequency being generated by the piezo element is the biggest issue. Too high (fast on/off) to really have the effect you probably want on the LED array. (I think) you want the LEDs to flash on when you strike the drum and stay off otherwise. You don't want the LEDs to modulate with the vibrations. So we would need to tank the piezo pulse in a basic RC circuit and use that to trigger the source/sink device that carries the load.

Sound about right?

 

[slapnpop]

The triggers are ususally hooked up to a controller, we're using them outside of typical use.

The triggers themselvers are just a raw piezo element connected to a jack. Typically the midi interface box contains all the electronics, but we're not using one.

You're correct about how the function should work. I've found something that's almost exactly what I need, a "light organ" kit from Velleman. The only problem is that it's input is made to work in parrallel with speaker leads, not a low-level piezo signal. Worst case scenario I pair it with one of thier 3 watt amplifiers.

Ideally, the adjustment pot would function to adjust the volume threshold where the flash actually occurs.