Double door bell (CB7559E)

Found in an Elektor from the 90's, this double door-bell drive circuit switches a relay by triggering different points.

| Clique na imagem para ampliar |

20 W amplifier TDA1520Q (CB16670E)
This powerful amplifier was part of commercial sound circuits from the 90s. The integrated circuit...
500 Hz Tone Emitter (CB13469E)
This circuit generates a control tone that serves to adjust amplifiers, check audio cables. The...
Locked Micro Alarm (CB1513E)
This circuit locks when the sensors are opened. The relay can be 6 or 12 V depending on the power...