Found in RCA documentation from the 1970s, this circuit is intended for firing thyristors in inverter circuits. The components are from the era and the operating frequency is 10 kHz.
Found in documentation from the 1980s, this amplifier uses an integrated circuit from the time....
The purpose of this circuit is to monitor the operation of an alternator in cars with a 12 V...
High selectivity filters can be obtained by combining same frequency crystals in series as shown...