This circuit uses a quadruple operational amplifier of the time. The circuit is from the 70s but can be implemented with modern operators that require the use of a symmetrical source.
This audio-driven relay was published in the July 1977 issue of Radio Electronics magazine. The...
This circuit can be used for signaling a panel with a common incandescent lamp. The lamp will...
This crystal oscillator is indicated for the calibration of IF steps of common radio receivers. The...