Found in a 70s RCA manual, this circuit uses transistors from the era. Equivalent types can be used such as TIP31 for Q1 and BD135 for Q2.
This circuit was obtained from an English publication from the 70's. The circuit is still current for...
This circuit was found in a 1979 magazine. We can use any JFET like MPF102 or BF245. The relay is 12 V...
Found in Motorola documentation from the 90s, this circuit can be implemented with current...