We found this circuit in the 1982 SGS linear integrated circuit manual. The L149 is not common today and the circuit can be implemented with equivalents.
Suggested by a 90’s Radio Electronics, this circuit automatically activates the recording switch of an...
Found in a 1960s Electronic Design, this circuit provides a signal from the sensing of an analog...
Operating at a frequency of around 180 kHz, this transmitter was found in a Science & Electronics...