This basic Schmitt trigger was found in an American publication from 1968. The circuit uses transistors from the time. Modern general-purpose types can be used.
This circuit intermittently activates a relay. It was obtained in a 1980 publication. In fact, we...
Suggested by a Popular Electronics, this small amplifier that has a detector to follow RF...
This source gently applies the voltage to the load, causing it to rise slowly, thus avoiding...