This circuit was published in an article in Radio Electronics magazine in October 1988. It uses components that are still common today, except for the sensor, which is a special type from that time.
This 2-quadrant modulator circuit was found in the May 1988 issue of Radio Electronics magazine. The...
This circuit was obtained in documentation from the 1980s. The triac and the unijunction support...
This circuit uses unijunction transistors and drives a small speaker through an output...