Found in American documentation from the 1980s, this circuit makes use of components of the time, which are uncommon today. The circuit detects the approach using a sensor formed by metal plates.
The selected circuit was obtained in a Texas Instruments opto-electronics manual. The transistors can be...
This circuit is suggested by Texas Instruments' Linear Circuits Applications. It consists of an...
This is a typical quartz crystal oscillator for the 3.5 MHz frequency (80-meter range) used in...