This very low frequency circuit was found in a 1964 Electronic Design. Transistors may be modern equivalents. The filter is low pass type.
The CMOS 4046 integrated circuit is not very common today, consisting of a very efficient PLL for...
This old circuit is suitable for signaling applications. The lamp must be incandescent, and the...
In the figure we show how the half wave rectification of a signal can be done using an operational...