This circuit was found in an Electronics World of 1968. Its purpose in triggering a relay when the circuit receives signals from a vibration sensor. The circuit is used in emergency situations.
This circuit was found in a 1975 documentation. The SCR can be of any type and in this case, we...
This fuzz circuit is more elaborate with the previous ones, as it has a selection switch that...
The XR2206 is not a common component today, but if you have one you can build this function...