On Wed, Feb 23, 2011 at 7:58 PM, Jones Beene <[email protected]> wrote: > No, no. It is not the PLC which is supplying the high frequency range. > > The thermistor material itself (barium titanate, no less) is "piezoelectric" > so supplying DC current to it produces ultrasound as an intrinsic feature. > Get it?
Maybe I do not understand the piezoelectric effect. I thought constant bias caused crystal stress and vice versa. How does a constant bias cause oscillations. Hmmm. Quartz (crystal) oscillators do indeed work that way. Off to do research . . . T
