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.
This circuit was found in an American audio documentation from 1968. The configuration can be...
This TTL pulse stretcher or stretcher was found in a 90's EDN. The time constant R x C1 determines...
This circuit was found in July 1986 Radio Electronics magazine. The maximum current is 1.5 A. The...