Using one unijunction transistor and two bipolar transistors, this circuit generates a signal from 25 Hz to 3 kHz. The circuit is from Electronics Now magazine, January 0, 1994.
The automatic modulated siren circuit shown in the figure really produces an interesting sound...
This circuit for incandescent lamps was found in a 70s documentation. The circuit uses an SCR...
In the figure we have a circuit in which two moving bar/dot indicators are connected together to...