It serves as a reference, since today we can have simpler and more compact solutions. This circuit is from an Electronics Experimenter Handbook from 1992. The integrated circuits are from that time.
This circuit was obtained from Radio Electronics from the 90s. The infrared sensor is of an...
This circuit is suggested by Motorola and is based on a 1723 voltage regulator. The 2N3055...
Found in documentation from the 1980s, this circuit generates signals that can reach a few...