This buzzer trigger can be used for small alarms. We find it in an 80’s American documentation. The supply can be done with voltages from 3 to 18 V.
This circuit uses an optical door opening sensor sensing the action of ceiling light or another...
This circuit can be used as a basis for the design of battery chargers with up to 1.5 A of...
This assembly is from 1957 from a Raytheon manual, but can be modernized using a BC548, 6 V power...