TTL Counter (CB21360E)

This counter from 0 to 9999 was found in English documentation. The power source must be 5V with at least 1A.

Powerful FM Transmitter (CB18668E)
This small transmitter with 2 transistors can reach several hundred meters using a 30 to 70 cm...
Electromechanical Totalizer Powered by Light (CB12099E)
This circuit was found in a Modern Electronics from 1990. It activates an old electromechanical pulse counter,...
Integrated Mixer LM1900 (CB19608E)
Although the integrated used originally is uncommon today, more modern operating equivalents can...