This circuit was found in Philips documentation from 1967. The components are of the time, being transistors like BCY38 for TR1, BC108 for TR3, and others depending on currents.
May 2016 - It can be obtained from Mouser Electronics new microcontrollers from Texas MSP430...
This circuit uses a PLL4046 oscillator to excite a piezoelectric ceramic. The circuit is from an...
Found in Linear Technology documentation, this circuit drains only 70 uA of the monitored circuit....