Eight
Member level 2
Hello.
I've been looking at some piezo elements with their driving circuits online, and I'm puzzled by a few things. A piezo element is supposedly a capacitive load, and, according to some forum posts, the polarity doesn't really matter. The manufacturers normally specify their rated peak-to-peak voltage. Now, suppose I have a driving circuit, which generates a 16Vp-p 50% duty cycle square waveform at 1 kHz. Assuming the piezo transducer is rated for this voltage, I'd like to feed the given waveform to the element, but I'm mystified how to correctly connect the device.
Should I connect one end to the driving circuit and the other to ground? Or should I create a low-impedance virtual ground at +8V in place of the normal 0V ground (or rather use a square wave generator i.e. a full-bridge that generates output from -8 to +8V in respect to the ground rather than 0V to 16V range)? See the attached picture. In both cases the element will be driven by a 16Vp-p range, but the mean voltage will shifted by 8V down to ground, allowing negative voltage to appear on the piezo element.
What is the difference in performance when driving a piezoelectric transducer in the two given ways?
I've been looking at some piezo elements with their driving circuits online, and I'm puzzled by a few things. A piezo element is supposedly a capacitive load, and, according to some forum posts, the polarity doesn't really matter. The manufacturers normally specify their rated peak-to-peak voltage. Now, suppose I have a driving circuit, which generates a 16Vp-p 50% duty cycle square waveform at 1 kHz. Assuming the piezo transducer is rated for this voltage, I'd like to feed the given waveform to the element, but I'm mystified how to correctly connect the device.
Should I connect one end to the driving circuit and the other to ground? Or should I create a low-impedance virtual ground at +8V in place of the normal 0V ground (or rather use a square wave generator i.e. a full-bridge that generates output from -8 to +8V in respect to the ground rather than 0V to 16V range)? See the attached picture. In both cases the element will be driven by a 16Vp-p range, but the mean voltage will shifted by 8V down to ground, allowing negative voltage to appear on the piezo element.
What is the difference in performance when driving a piezoelectric transducer in the two given ways?