This servo circuit was found in 1969 Motorola documentation. Integrated circuits and transistors are types of the time, hard to find today.
This circuit is self-powered, that is, the sinusoidal signal that must be converted into a square is...
This audio-driven relay was published in the July 1977 issue of Radio Electronics magazine. The...
This is the traditional configuration of a high-pass filter with an operational amplifier, such as...