Institute Newton C. Braga

Circuit Bench

10 Hour Timer (CB18957E)
This long-time circuit uses a field effect transistor, which may be the BF245, and depends on a...
Two meter amplifier (CB8980E)
This circuit for the two-meter band of radio amateurs was found in 1980s documentation....
Doorbell Sound (CB16704E)
This audio oscillator circuit was found in a 1992 publication. In the original article it is...