Audio Cable Tester (CB3827E)

This simple circuit tests both monophonic and other two-wire audio cables. The circuit is powered by two common batteries.

7 Segment Experimental Display (CB17499E)
This didactic circuit makes the sequential activation from 0 to 10 to demonstrate the functioning of a...
9 V x 40 mA power supply (CB12849E)
This power source was found in an old Argentine publication from 1973. The transistor could be the...
Low Voltage Oscillator (CB6188E)
This circuit operates at a voltage of 1.3 V from a single mercury cell. We found in an old...