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How to make piezo trigger lights? Answered

Hi, I wanted to make a piezo trigger that everytime it hits, it lights up a 2 meters led strip. I found a schematic, but have no idea how to read it. What would I need to get it to light up a 2 meters led strip, running on batteries. I also want it so everytime the piezo is hit, the light flashes a different color. thanks.


I leave the circuit to you to assemble - You going to need the bits:

A Piezoelectric sounder
4148 diode
4.7 Meg ohm resistor
0.1 microfarad capacitor
BSS84ZX FET transistor. (data sheet here http://www.datasheets.org.uk/250--BSS84*-datasheet.html)

You going to need to connect them I suggest strip or Varoboard is easiest for a beginner.

The mosfet connections are diagrammed below.


The circuit only gives a pulse when the sounder is tapped - You will need to be able to latch that pulse for however long you need - although perhaps a brief pulse of light will suit you.

Connect the LED strip to the end assuming the 5 volts will be enough to drive the LEDs if not you may need a relay or further transistor to supply higher power.

ok, here is what I got so far. I have look up most of the schematic, and pretty sure all of them are facing the right direction. for the bss4zx, where does the "OUT" go? and does the battery go to the "+5V"? and where does the led go?

here is the picture.


Im looking at the large picture and im sorry im still confused.

The out goes to what ever you want to switch - The BSS84ZX acts like a switch.

Initially connect an LED with a series resistor 330 ohms.

The battery + goes to + and the negative to yjr other side of the LED (load) you have connected. IF all is OK when you tap the sounder you should see the LED flash.

The diode 4148 should be connected with the band on the case towards the sounder.

The 0.1 micro farad capacitor should have one wire marked with a grey band or a dent in the case this is the negative end and goes towards the BSS84ZX

ok, here is how mine looks like after soldering it up. I don't know if the BSS84 is suppose to be that small. and still confuse about the led parts too.in the picture, so I jsut connect the red wire of the light to the battery, ad the white wire with the black one? http://img848.imageshack.us/img848/9885/20120503002049.jpg

If I need a higher voltage, do I just more transistor like next to a 4.7M? Another question is what is 'OUT' is that ground? and at the the +5v end, is that a single wire? don't led have a + and -? thanks again.


2 years ago

Hello, Ive been looking for this circuit for a long time. My problem I do not know how to read a schematic. Is there any way I can pay you or beg you to change the schematic into a wiring diagram (point to point ) for me? Please . I went on line to Mosure they have all these parts. Also I happen to have 25 TP-31 transistors. Would that work in place of the one you have? If not no problem.

Why a Piezo?
Why not an easier type of switch?


I am usin a piezo since its the best to pick up a drum vibration.

No The device marked 4148 is a diode.

The output will go from 0 volts to +5 volts when the piezio is tapped. the MOSFET transistor is acting as a switch normally off it will turn on when the sounder is activated.

To get a higher voltage you might be best using a 5 volt relay as in the diagram below

The relay is just used to switch the higher voltage for the LEDs Find a 5 volt relay as the output is 5 volts.