This circuit is from a 1972 Motorola publication. The used transistor can still be found, but it can be used equivalent. The circuit is powered by the amplifier with which it must operate.
This interesting circuit provides an output proportional to the input voltage, regardless of its...
The proposed circuit generates signals in the range between 9 kHz and more than 44 kHz, which, it is...
A modulated (intermittent) siren, using the four gates of the 4001 integrated circuit is shown in the...