The RCA integrated circuit used in this control is uncommon today. The circuit is from an Electronics Now from July 1995. The sensor determines the value of the adjustment potentiometer.
This TTL circuit is from a Radio Electronics magazine from February 1973. The circuit must be...
Common operational amplifiers like the TL series, CA3140 and others can be used in this circuit...
This circuit uses only two common transistors and provides good audio power in a speaker. Readers who...