This circuit can be used as a shield for microcontrollers. The relay is power compliant, and the transistor is general purpose.
We found this circuit in the Radio Electronics magazine of May 1977. The circuit has the frequency...
This 200 kHz oscillator was found on a 90's EDN. It consumes only 2.8 mW and has CMOS compatible...
This tracker for audio and RF signals was found in old American documentation. Transistors and...