Darkness Monitor (CB21019E)

Found in Popular Electronics this circuit triggers an SCR and lights an LED when the location of the sensor is dark.

| Clique na imagem para ampliar |

Code Practice Oscillator (CB22251E)
We found this circuit in an American documentation from the 50's. The transistor is made of...
Glitch Detector (CB20896E)
Found in a Popular Electronics from the 80's, this circuit triggers an SCR keeping an LED on when...
Wide Band Oscillator (CB4932E)
The frequency of this oscillator can be set in a range from 5000 to 1. We found it in an old...