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.
We found this circuit in a 1967 American documentation. The diodes are general-purpose and the...
This circuit uses a pressure switch to turn a relay on or off. The supply must be 6 or 12 V...
The selected circuit was found in the Texas Instruments optoelectronics manual. RC and C1...