This circuit was found in Intersil's documentation from the 70's, being indicated for powering operational amplifiers. The circuit divides the voltage from a single source.
This proximity (capacitive) alarm triggers a relay that, in turn, triggers an audible warning...
This sensitive circuit was found in old documentation. The SCR can be any of the 106 series and...
This traditional multivibrator configuration uses an LDR as a sensor. The circuit emits sound when...