Shortening piezoelectric decay itme

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wrongbat

New Member

• Jul 13, 2015

• #1

Hey there!

I'm using a square wave signal to drive a piezoelectric transducer. The transducer I'm using has a decay time of around 1.3ms. Is it possible to shorten the decay time by reversing the square wave signal (that is phase shifting it by 180˚) for a short period?

Thank you!

 

audioguru

Well-Known Member

Most Helpful Member

• Jul 14, 2015

• #2

You probably will not drive it with the correct phase to stop its resonance. How about shorting it?

 

AnalogKid

Well-Known Member

Most Helpful Member

• Jul 14, 2015

• #3

Not enough detail to hazard a guess. Are you saying you are driving it with an ultrasonic high frequency square wave, and it is ringing after the waveform ends, or it is a self-oscillating beeper and you are driving it with a DC level, and the audio has a tail on it, or what?

ak

 

alec_t

Well-Known Member

Most Helpful Member

• Jul 14, 2015

• #4

I'm with AG. Shorting it seems the simplest way.

 

crutschow

Well-Known Member

Most Helpful Member

• Jul 15, 2015

• #5

Shorting it will only help if the square-wave driver has a significant output impedance. Otherwise the driver would already look like a short.

 

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Diver300

Well-Known Member

Most Helpful Member

• Jul 15, 2015

• #6

A resistive load would absorb power faster than if you shorted it.

 

audioguru

Well-Known Member

Most Helpful Member

• Jul 15, 2015

• #7

He does not say why he wants to shorten the ringing time.
I think the piezo transducer transmits an ultrasonic beep then is used as a echo receiver to determine distance. It cannot receive if it is still connected to a low impedance transmit circuit, so the circuit must be disconnected from the transducer, but maybe it is disconnected too soon.