substitue for piezo sensor

here's our circuit that we're going to make

lhttps://xtremecircuits.blogspot.com/2012/12/simple-knock-alarm-with-piezo-sensor.html

is there another sensor that i can use to replace piezo sensor? please help me

whats ur target? what u wanted to do? if we know more about ur requirement we can suggest u better solution.

still u can replace piezo sensor with condenser mic which we use comonly in phone, mobiles, voice recorder etc. but check the polarity before u connect cond mic. it has polarity.

if u want to varry the sensitivity replace the 1M resister just above the piezo/cond mic. for cond mic u can put 1K to 1M. I'll suggest u to put 10K.
(for test purpose put 1M preset series with 10K resistor)

- - - Updated - - -

did u see this? http://www.extremecircuits.net/2012/03/door-knock-alarm-with-timer.html
this will be better than that.

u can replace piezo with condenser mic. for that u need to remove the resistor across piezo and reduce the resistor value from 2.2M to 10K or 22K just above sensor.

Refer atached circuit.

thanks for help.i just want the same circuit but the sensor to be replaced only that's all.

s u can try with cond. mic

on the circuit i posted, vibration will be our input. so when i change the sensor with mic it will be the same input?

A piezo is easily mounted so it detects vibration.
A microphone will pickup all kinds of background sounds and will not pickup much vibration.
Also, the very low base-emitter voltage of the first transistor is too low to power the electret mic.

can you give me any suggestion about that matter?

A piezo transducer is what you need to detect vibration. Why don't you use one??

A piezo transducer is used in a smoke detector. A smoke detector must be replaced every 10 years so there must be many that are thrown away. Get one.
There are many piezo guitar pickup articles in Google that explain how to mount it.

aarviii said:

is there another sensor that i can use to replace piezo sensor? please help me

Click to expand...

Try piezo from cigarette lighter:idea: One end is rigidly mounted on the second can be hung from a small weight. The vibrations are bent rod.

Variety of Piezo metal will be available in electronic shops. Alternate source for a piezo metal is Piezo buzzer. Break the piezo buzzer carefully without damaging piezo metal disc.

In vinil player may be Piezo phonograph cartridge.