Digital Inverter with PNP Transistor (CB25626E)

This circuit inverts the signal of any logic using a general purpose PNP transistor. The supply voltage determines the logic.

Tic Tac Toe with LEDs (CB4322E)
We found this circuit in a 1986 documentation. It uses only LEDs, batteries, resistors and the...
Automatic Control For Pumps (CB4437E)
This circuit is from a 1988 documentation, but uses components quite common today. The circuit...
Hybrid Amplifier (CB25724E)
This interesting high-quality amplifier configuration was featured on the cover of the June 1994...