This circuit was obtained from an American 1980s documentation. The frequency depends on the crystal and the circuit may be a PNP that reaches the generated frequency.
Found in Motorola's 1968 power circuit manual, this circuit has a high input voltage and no...
The circuit shown in the figure can be used to detect vibrations or to provide amplified acoustic...
This circuit is from a1970 documentation. R1 may have 10k and P1 47k. The transistors can be BC558...