Institute Newton C. Braga

Circuit Bench

Telephone Repeater (CB12031E)
This circuit, obtained in a 1981 English magazine, is nothing more than a sound switch. Placed near...
Blocking Oscillator (CB25313E)
We found this circuit in Electronics Now magazine from 1996. The frequency is basically given by...
Musical Doorbell (CB12314E)
This circuit is from a 1988 publication, but we can assemble it with some component changes. For...