This circuit was obtained in a documentation from the 70s. The operational amplifiers used are uncommon today. Modern equivalent types can be tried out.
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...