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 1995 circuit uses an audio amplifier that is no longer common today. However, other...
The phototransistor of this alarm can be of any type. The relay must be sensitive type according...
This digital clock has a traditional configuration with well-known CMOS integrated circuits. The...