Found in an old American publication, this circuit generates signals of various waveforms. The frequency depends on the components. Operational amplifiers are from the period.
This control panel allows the use of NO and NC sensors, turning the alarm on after 30 seconds...
This circuit, found in a 1989 publication, only works with incandescent lamps. The maximum power...
We found this circuit in a 1968 Electronics World. The potentiometer should be set to trigger the SCR...