This circuit has the function of automating some type of equipment when a powerful transmitter is activated nearby. The circuit was found in a 1967 documentation.
The frequency of this astable depends on the capacitor that can be changed over a wide range of...
This circuit is from a documentation from the 90s. The transistor can be any general-purpose FET...
In the figure we have one of the many options found in this section for an intercom using ordinary...