This circuit was found in the magazine of radio amateurs 73 in a 90's edition. The components are current and the transistor is of general use.
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...