Institute Newton C. Braga

Circuit Bench

Light Alarm with the 741 (CB12591E)
The sensor for this alarm is an LDR and it consists of an oscillator that goes into action when...
Magnetic proximity sensor (CB7920E)
This sensor triggers an oscillator emitting sound when a magnet is approached by a reed switch....
Regenerative superheterodyne (CB23730E)
This interesting circuit of a one-transistor receiver was found ina march 1961 Radio Electronics...