This circuit, found in a 1958 magazine, is for reference only, since the components are not easy to find today. The transistors are germanium types and power supply is made by common cells.
The SN72741 integrated circuit is nothing more than the version of Texas Instruments of the known...
This circuit generates interval signals controlled by a light sensor. The basic time of the sound...
This circuit is from 1999 documentation. The integrated circuit used is not very common today. Both...