Timeline for Quantifying the piezoelectric effect of ceramic capacitors
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
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| Sep 12, 2014 at 14:00 | comment | added | Scott Seidman | Yup, the series cap Ce is a term corresponding to the elasticity of the crystal. These are pretty interesting models, with some of the electrical elements being electrical elements, and some being electrical analogues of mechanical elements. | |
| Sep 12, 2014 at 13:52 | comment | added | George Herold | @ScottSeidman, Re: models. Ah right. (looking at wiki) there's a series capacitor between the voltage source and bulk capacitance. For the (one) peizo transducer that I've used the low frequency time constant was about 1 second or so. (It's been years since I looked at it.) | |
| Sep 12, 2014 at 13:27 | comment | added | Scott Seidman | en.wikipedia.org/wiki/Piezoelectric_sensor -- lots of great models. In fact, at high frequency, you have to model the inertia of the crystal as an inductance to show proper resonance. | |
| Sep 12, 2014 at 13:17 | comment | added | George Herold | Yeah that makes sense, @ScottSeidman. I'd model the piezo as a voltage source in parallel with the cap. And sure if there is some leakage current it will be less.. but that would be a fairly low frequency.. a long time. | |
| Sep 12, 2014 at 13:10 | comment | added | Scott Seidman | Piezo can get pretty attenuated at low frequency. How low would depend on the input impedance of the upstream amplifiers, and to some extent, the nature of the crystal itself. Essentially, a piezo crystal is like a cap, with charged plates separated by an insulating crystal, but the crystal has a finite resistance, as does the upstream amp, so the charge leaks away. | |
| Sep 12, 2014 at 12:57 | history | answered | George Herold | CC BY-SA 3.0 |