This harmonic oscillator controlled by crystal was found in an American documentation of the 90's. The circuit uses transistors of the time. Current equivalents can be used.
This digital circuit is from a Radio Electronics magazine from December 1991. It does not use a...
This circuit is an isolated shield for microcontrollers such as the Arduino, MSP430, PIC and...
August 2017 - This Maxim component, available from Mouser Electronics, is ideal for wearables,...