Found in an Elektor from the 90s, this circuit converts signals from the 280 kHz band to 516 kHz, making it possible to tune them in common AM radios. The components used are from that time.
This circuit was obtained in the Philips integrated circuits manual of 1990. The indicated power is...
In the figure we show an application in which the 4093 excites a stage with 4 transistors in the...
This 1995 documentation circuit detects when an extension on a phone line is active. Adjustment of the...