Institute Newton C. Braga

Circuit Bench

Crystal Radio (CB21207E)
This crystal or galena radio was found in documentation from the 1990s. The earpiece must be a...
Milliohmmeter (CB25813E)
This very low resistance meter was found in the February 1995 issue of Electronics Now magazine. The...
Sinusoidal audio generator (CB8644E)
Found in a 90s QST, this circuit uses an operational amplifier that is still common. It generates...