Telephone dialer (CB9235E)

This circuit was obtained in Radio Electronics from the 90s. The integrated circuit is uncommon today.

| Clique na imagem para ampliar |

600 ohms line Amplifier (CB16795E)
This circuit uses a 741 operational amplifier that must be powered by a symmetrical source of 6 to...
Oscillator 4011 (CB14983E)
This adjustable oscillator has the traditional configuration already presented in other articles. The...
Simple Power Supplies (CB20187E)
In the figure below we have the main configurations of power supplies with the most used...