Institute Newton C. Braga

Circuit Bench

Music box (CB8626E)
This circuit was found in a 90s Popular Electronics. It uses an LS3404 melody chip that has...
Rectangular Oscillator (CB12685E)
The base of this circuit is one of the four Norton amplifiers existing in an LM3900 integrated circuit....
OR gate LM3900 CIR6569S CB15637E (CB15637E)
A 3-input OR gate can be made with an LM3900 amplifier, as shown in the figure. The purpose of the...