Diode Tester (CB22137E)

This diode tester was found in an English publication from the 1980s. Transistors are general-purpose types of the time.

Second Order 1 kHz Low Pass Filter (CB13444E)
This filter was found in a 1975 American technical publication. The filter can be of any type and...
Motor Control (CB24934E)
This motor logic control was found in the September 1985 issue of Radio Electronics magazine. The...
Modulated siren 555 (CB8651E)
This configuration can be found elsewhere on this website and section. The circuit is from Popular...