Diode Tester (CB22137E)

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

Touch Switch (CB13983E)
This circuit, very traditional, was found in a practical Elettronica of 1977. The source cannot be of...
BTL Amplifier TDA2020 (CB4358E)
This integrated amplifier was found in a non-existent British magazine from 1975. The used...
Precision Current Source (CB21052E)
Found in National Semiconductor documentation from the 1990s, this circuit employs basic...