Cable Locator (CB21303E)

This audio detector circuit can be used for cable identification. We found it in a Popular Electronics from the 90s.

DC motor control (CB22298E)
This circuit was obtained from an American publication from the 60's. The transistors are...
Differential Light Sensor (CB11589E)
This circuit detects light variations using two LDRs as sensors. Operational amplifiers and...
Audible Indicator for Car (CB26291E)
Using the 555 this circuit was found in a Popular Electronics from the 90's. The circuit directly...