Signal generator (CB21057E)

Found in Popular Electronics, this '90s circuit generates harmonic-rich signals for testing audio equipment.

Fluorescent Rhythm Light For the Car (CB3810E)
This 1987 circuit uses a common ignition coil to generate high voltage to power a fluorescent lamp that...
Electronic Drums (CB26221E)
The sound of drums can be obtained with these two touch-triggered double-T oscillators. The...
Photodiode Comparator (CB20688E)
This high-precision circuit was found in documentation from the 1990s. The integrated circuit is...