Intermittent buzzer (CB20494E)

This two-tone buzzer can be powered by a solar panel. The circuit is from a 1991 documentation. The transistor is a general-purpose type.

Flip Flop with the Operational LM3900 (CB4510E)
Other series amplifiers such as the MC3301, MC3401 and LM2900 can be used on this circuit. We...
CMOS Touch Switch (CB222E)
To small metal plates are used as sensor in this circuit. The skin resistance is enough to trigger the...
Transistor RIAA Preamplifier (CB1372E)
We found this circuit in documentation from the 1970s; The circuit uses Japanese transistors of...