This circuit that emits siren sound can be used in a fire alarm. We found it in an old American documentation. The signal must be applied to a good audio amplifier.
MCP19124/5 Contains Independent Voltage and Current Control Loops Plus a Full Suite of...
A flash of light on one sensor or the touch of your fingers on the other type of sensor will turn...
This 1-transistor timer was published in Radio Electronics magazine in December 1960. The circuit has...